atrophy, slow pulse-rate, somnolence, and coma. The temperature is
variable, more commonly rising during the more acute stages of the
disease, and falling to normal or subnormal during the quiescent
periods.
Localizing features are to be found in squints, inequality of pupils,
retraction of the head and neck, dyspnœa, and dysphagia, whilst
compression of the cortical motor centres is evidenced by twitchings,
convulsions, and spasticity of the limbs. General convulsions are by no
means uncommon. Remissions and intermissions of both local and general
symptoms are frequently observed, paralyses, for example, fluctuating in
depth and character.
_B._ The bones comprising the vault of the skull become greatly thinned
and widely separated from one another, the fontanelles enlarged, and the
sutures unduly prominent. The head becomes enlarged in all directions,
and its increased weight renders the child incapable of retaining
postural control, the head being top-heavy and falling about in all
directions.
The bones of the base share in the deformity. The pressure exerted on
the orbital plates of the frontal bone force the globe in the downward
direction in such a manner that the infra-corneal sclerotic is obscured
by the lower lid, whilst the supra-corneal portion is unduly prominent.
The bony eminences in the region of the sella turcica are diminished in
size, the middle fossa of the skull flattened from side to side, and the
posterior fossa from before backwards. In such cases the skull assumes
an almost dolicocephalic appearance. In any case, the disproportion
between the enlarged skull and diminutive face is a marked feature.[14]
The scalp becomes stretched, hairs are sparse and brittle, and the veins
dilated.
=Treatment.= _Indications for operation._ The results obtained by
operation for internal hydrocephalus are not sufficiently encouraging to
enable the surgeon to urge immediate operative treatment.[15] Still, it
is perfectly clear that he cannot possibly carry out surgical treatment
with benefit to the patient if the ventricular distension is allowed to
progress to such a degree that marked cortical flattening and
degeneration occurs. No fixed probationary period can be laid down as a
guide, each case must be judged on its own merits. Special attention
should be paid, however, to the disks and lower extremities. Any
suggestion of optic neuritis or spasticity should be regarded as
urgently demanding operative interference.
_Lumbar puncture_ cannot be expected to confer other than temporary
benefit even under the most favourable circumstances, whilst, in the
event of interference in the normal communication between the
ventricular and cerebro-spinal spaces, no relief can be anticipated.
Connal recommends that lumbar puncture should be carried out daily, or
twice daily, over extended periods of time. This operation, however, is
by no means devoid of danger, and the results obtained by such treatment
are not at all satisfactory.
=Operation.= Operations are carried out (_a_) with the object of
withdrawing fluid from the distended ventricular cavities (ventricular
puncture), and (_b_) to establish a communication, or short-circuit,
between the ventricular space and other spaces (ventricular drainage).
_Ventricular puncture._ This operation may be carried out through the
anterior fontanelle, through the frontal bone, or over the descending
cornu of the lateral ventricle.
_Through the anterior fontanelle._ The region of the fontanelle is
shaved and cleansed in the usual manner, after which the surrounding
parts are cut off from the field of operation by a large sheet of gauze
or lint, in which a hole is cut sufficing to allow of exposure of the
site of election for puncture.
The patient should be in the recumbent position, the head well towards
the end of the table. The operation is performed without an anæsthetic
or under local anæsthesia. A site is chosen at the outer angle of the
fontanelle, about 1 inch away from the median antero-posterior line,
thus avoiding all possibility of injuring the superior longitudinal
venous sinus. The trocar and cannula, of small size, is passed directly
inwards, towards the base of the skull, for a distance of not more than
2 inches. The trocar is withdrawn and the fluid allowed to escape
slowly. If the cerebro-spinal fluid escapes at high pressure, the flow
should be regulated by the finger placed over the mouth of the cannula,
and, in any case, it is inadvisable to allow of the withdrawal of more
than 50 c.c. (approximately 1¹⁄₂ ounces) at one sitting. The cannula is
withdrawn and the site of tapping covered with collodion gauze. Even
when adopting all precautions the operation is not without danger, and,
added to this, is the fact that few surgeons care about introducing an
instrument blindly into the cerebral cortex--the risk of puncturing one
of the distended superficial cerebral veins is sufficiently obvious.
_Through the frontal bone._ Tillmanns, in recommending this procedure,
states that ‘the needle should be inserted about 2 centimetres from the
central line and 3 centimetres from the precentral sulcus. You strike
the ventricle at a depth of from 3 to 5 centimetres’. He claims that
this method leads to satisfactory results. It is open, however, to all
the objections of puncture through the fontanelle.
_Over the descending cornu of the lateral ventricle._ This operation is
strongly recommended by Keen on the ground that excellent drainage is
supplied. A point is mapped out on the skull which lies 1¹⁄₄ inches
behind the external auditory meatus and the same distance above Reid’s
base-line. If the postero-lateral fontanelle be open a small trocar and
cannula may be introduced at the upper angle of the space--thus avoiding
the lateral sinus--and passed inwards in a direction towards the summit
of the opposite ear. If the fontanelle be closed, a scalp-flap is framed
and a bone-disk removed with a ¹⁄₄¹⁄₂ inch diameter trephine. The dura
should not be opened. The evacuating instrument is then introduced
through the membrane in the same direction as before. In either case it
should not be passed for a greater distance than 1¹⁄₂ inches, and, in
all cases, the exploration should be of a progressive nature, that is to
say, the trocar should be withdrawn once for each ¹⁄₂ inch of brain
substance perforated. The escape of cerebro-spinal fluid must be
regulated in the manner previously described.
If trephining has been necessitated, the bone-disk is not replaced, thus
allowing of subsequent tappings through the trephine-hole, this gap now
taking the place of a patent postero-lateral fontanelle.
Keen’s method of ventricular puncture presents many advantages over
other methods, though still open to the objection that the actual
central puncture is done blindly.
=Ventricular-subdural drainage.= A point is mapped out on the scalp
which corresponds to the surface-marking of the descending horn of the
lateral ventricle (see p. 3), and, with this point as a guide, a
scalp-flap is framed, the base of which lies immediately below the
indicated spot whilst its convexity is situated between 1¹⁄₂ and 2
inches above. This flap should not include the pericranium. The flap is
turned down to its base, the pericranium stripped aside and a disk of
bone removed, at the upper part of the exposed bone, with a ¹⁄₄ or ¹⁄₂
inch diameter trephine. The bone is usually very thin.
[Illustration: A
B
FIG. 26. DIAGRAMMATIC REPRESENTATION OF THE AUTHOR’S OPERATION FOR
HYDROCEPHALUS INTERNUS. A. The osteoplastic exposure of the brain (A,
The bone; B, Upper two-thirds of trephine hole; C, Dura mater; D, The
four dural flaps; E, Site of brain perforation; F, The brain; G, Line of
fracture of bone-flap; H, The bone-flap; I, The Scalp; J, Lower third of
trephine hole). B. Ventriculo-subdural drainage (_s._, The scalp; _b._,
The bone; _d._, The dura mater; _v._, The lateral ventricle; _t._, The
drainage medium between the ventricular cavity and the subdural space;
_s.l.s._, Superior longitudinal sinus; _f.c._, Falx cerebri).]
When this disk is removed, the dura is separated from the bone, and,
with the aid of a strong pair of scissors, the bone is cut in such a
manner as to form a bone-flap, the margins of which lie well within
those of the scalp-flap (see Fig. 26). This flap is broken across at its
base, turned down, and covered with gauze.
At the lower portion of the exposed dura mater, a crucial incision is
made through the dura mater and a blunt-pointed trocar and cannula
introduced at the centre of the exposed brain, all visible vessels being
avoided. The diagnosis is now confirmed--by the withdrawal of the trocar
and the escape of cerebro-spinal fluid.
[Illustration: FIG. 27. THE CONVERSION OF HYDROCEPHALUS INTERNUS INTO
CEPHALOCELE.]
By the introduction of a bundle of horsehair or catgut, passed through
the cannula so as to project into the ventricular cavity, and, after the
withdrawal of the cannula, tucked, with respect to the proximal ends,
into the subdural, extra-dural, or subaponeurotic spaces, it is obvious
that drainage may be established between the ventricles and the other
regions. Experience showed, however, that drainage into the
subaponeurotic space usually converted the condition of hydrocephalus
into one of cephalocele (see Fig. 27), the fluid collecting as a
localized fluid tumour over the region of exploration, whilst
extra-dural drains did not permit of sufficiently rapid reabsorption of
fluid. Subdural drainage gave the best results, the cerebro-spinal fluid
being brought into relation with the pia-arachnoid meshwork of vessels.
It would, of course, be infinitely preferable if the ventricular fluid
could be brought into direct relation with the veins of the
_subarachnoid_ space, for the cerebro-spinal tension and venous pressure
are equal, and all excess of cerebro-spinal fluid would be absorbed as
soon as it is formed. This course is, however, impossible to carry out.
We have, therefore, to rest content with less direct contact, drainage
into the _subdural_ space. This ventricular-subdural drainage, as
obtained by horsehair, catgut, and silk, apparently leads to but
temporary benefit, probably owing to falling together of the brain
substance and obliteration of the adventitious passage.
Silver tubes and bone tubes have been utilized, but the results are
sometimes disappointing. In one of my recent cases the two halves of a
bone tube were utilized. The tube was cut across in an oblique manner at
about its centre, the two parts set at right angles to one another and
sewn together with silk. One arm is introduced into the ventricle, the
other tucked underneath the dura mater. The child improved considerably,
but the method is not altogether satisfactory and by no means easy of
application. In another case I utilized strands of silver wire. The
depth of brain-tissue necessary to reach the ventricular cavity was
measured, and two or three strands of wire introduced so as to project
well into that space, then steadied with forceps whilst the proximal
ends were bent at right angles to the surface of the brain and tucked
underneath the dura mater. The method was unsatisfactory.
Tubular drainage is not essential, for the fluid escapes from the
ventricle as much alongside the tube as through its lumen. Still, I
believe that tubular drainage is preferable to other methods, and,
realizing the difficulty of introducing a right-angled tube--one arm to
project into the ventricle, the other to lie beneath the dura
mater--Messrs. Arnold & Son are now making for me small and light
right-angled silver tubes so constructed that each limb can be inserted
independently, after which they can be locked together. This method
appears to overcome many of the difficulties previously encountered. The
tube is inserted after the formation of the osteoplastic flap, as
described above. The four dural flaps are then united, preferably by
cross union of their apices, the bone-flap is replaced, and the
scalp-flap sewn accurately into position. Collodion gauze, applied to
the wound, aids in the prevention of cerebro-spinal escape.
The scalp and bone-flaps are framed, and the dural incision carried out
low down, so as to make the opening to the brain as valvular as
possible. All these precautions are taken to avoid leakage of
cerebro-spinal fluid, a most troublesome complication--adding to the
risk of infection and often resulting in an acute eczematous condition
of the surrounding skin.
By this method it is hoped that a permanent fistulous communication will
be formed between the lateral ventricle and the subdural space.
=Ventriculo-abdominal drainage.= The following method of drainage has
been devised by Cushing: ‘It having been established that the ventricle
can be emptied by the lumbar route, and that the withdrawal of fluid is
not prejudicial to the child’s well-being, the following procedure is
carried out. A laparotomy is performed; the posterior layer of
peritoneum to the left of the rectum is split; the body of the fifth
lumbar vertebra, just under the bifurcation of the vessels is exposed;
the bone is trephined and one-half (the female portion) of a silver
cannula, exactly the size of the trephine, is inserted and held in
position. The child is then turned on his face and a laminectomy
performed; the subarachnoid space is opened, the strands of the cauda
separated, and the posterior half (male portion) of the cannula is
invaginated, so that it locks into the portion inserted anteriorly. Both
wounds are then closed. The fluid for a time finds its way into the
peritoneal cavity, but ultimately into the retro-peritoneal space whence
it is taken up by the receptaculum chyli, as experimental observations
have shown.’
Cushing has carried out this operation in 12 cases with a considerable
degree of success.
Recently, another method of treatment has been carried out by
Cotterill.[16] A large semilunar flap is made from the occipital region,
exposing the bone. Trephine circles are made on either side of the
median ridge, and the intermediate part of the bone, together with the
posterior part of the foramen magnum, is removed. The dura mater is
opened and the occipital sinus ligatured. The lateral lobes of the
cerebellum are then held apart, and the thickened arachnoid over the
posterior part of these lobes and over the roof of the fourth ventricle
exposed. This roof is opened. The wound is then closed.
By this method drainage from the ventricle is said to be reestablished.
Though without personal experience of this extensive procedure, one
cannot avoid expressing considerable doubt as to its advisability.
My own experience would lead me to the following conclusions:--
1. Whilst recognizing that internal hydrocephalus usually demands
surgical interference, it is only in some few cases that material
benefit results. Some recent successful cases point to the possibility
of better results in the future.
2. The operation which promises the best results, combined with
the least risk to the patient’s life, is that described as
ventriculo-subdural drainage.
[4] _Der Hirnbruch und seine Behandlung._ Moscow, 1896.
[5] _De la céphalhydrocèle traumatique_ (_Travaux de Neur. Chir._, iii.
1898).
[6] _Archives Italiennes de Biologie_, vol. xxxviii, p. 444.
[7] _Der Hirnbruch und seine Behandlung._ Moscow, 1896.
[8] _Beitr. zur klin. Chir._, vol. iii, p. 228.
[9] _St. Bart. Hosp. Reports._ Lawrence Ward. May 5, 1896.
[10] _Beitr. zur klin. Chir._, vol. vii, p. 228.
[11] _American Practice of Surgery._ Bryant and Buck.
[12] _Tumours, Innocent and Malignant._ Bland Sutton.
[13] _Brain_, 1902, p. 140.
[14] In estimating the size of the head, the following tables--after
Bonnifay--will be useful:--
_Age._ _Circumference of head_ (average).
Birth to fifteenth day 343 millimetres (approximate).
Fifteenth day to 2 months 368 „ „
At 3 months 388 „ „
Six months to 1 year 429 „ „
One year to 2 years 459 „ „
_Normal rapidity of growth of the head_
During the first 3 months 44 millimetres (approximate).
During 3 to 6 months 41 „ „
From 6 months to 1 year 30 „ „
During second year 14 „ „
It should be noted that enlargement of the head can only take place
during the years previous to synostosis of the skull bones. Leonard
Guthrie (Harveian Lecture, March 17, 1910) writes, ‘I cannot find from
any recorded cases of hydrocephalus acquired in later childhood and
adult life that an increase in the size of the head has been any aid to
diagnosis, and I believe it is true that internal hydrocephalus acquired
after the sutures are set is hardly distinguishable from a
non-localizable intracranial new growth giving rise to headache,
vomiting, and optic neuritis.’
[15] The treatment for acquired hydrocephalus dependent on tumour
formation is discussed elsewhere. This section deals with the congenital
variety and with those cases of acquired hydrocephalus not due to
obstruction by tumours.
[16] _Review of Neurology and Psychiatry_, vol. ix, No. 1, p. 1.
CHAPTER IV
FRACTURES OF THE SKULL
=General considerations.= Fractures of the skull do not form more than
one-twentieth part of the fractures admitted annually into the
hospitals, but, in spite of this relative infrequency of occurrence, the
difficulties attendant on diagnosis, the numerous associated
complications, and the all-important question of treatment, invest this
subject with a special interest.
The whole question of skull fractures is beset with difficulties, many
of which, it is hoped, will be swept away in this and subsequent
chapters.
Brief allusion must first be made to some important points in connexion
with the anatomical structure of the skull, such as bear relation to
fractures and aid in the appreciation of the extent and mechanism of the
fracture.
The =vault= varies in density to a remarkable degree, not only in its
several parts, but also in different individuals. Cases have now and
again been recorded in which a very trivial blow, totally insufficient
to produce any definite osseous lesion in the normal individual, has
resulted in the production of a vault or basic fracture. Each case,
therefore, must be judged on its own merits.
The vault derives its strength from its shape and structure. The two
tables are of equal strength, and, for the most part, separated from one
another by a variable amount of diploic tissue. This diploe is most
abundant in the frontal, parietal, and upper occipital regions. These
parts are proportionately strong. Two regions are practically devoid of
this inter-tabular buffer--the squamo-temporal and cerebellar (see Figs.
29 and 30). A recognition of this comparative weakness is of great
practical importance in view of the fact that both these regions are
liable to special lesions--injury to the middle meningeal artery in the
first case, and, in the second, cerebello-medullary lesions. Nature’s
‘mistake’ in providing coverings unsuited to requirements has been
compensated for in part by additional protection--the temporal and
nuchal muscles.
[Illustration: FIG. 28. DIAGRAM ILLUSTRATING THE LINES ALONG WHICH
FORCES RECEIVED ON THE VAULT ARE TRANSMITTED TO THE BASE. (For further
description, see text.)]
Further, not only does the skull vary in density in its several parts,
but it is also ribbed and strengthened by various bony bars and
buttresses that pass up from base to vault (see Fig. 28). These
‘ribbings’ are seen to extend upwards from the crista galli, from the
external angular frontal process, from the auditory region, and from the
occipital protuberance. Presumably, these ‘ribbings’ were so constituted
for a definite purpose; in any case, it is clear that they play an
important part in the reception and conduction of forces to the base of
the skull. It is apparent, moreover, that the parts intervening between
these ‘ribbings’ are liable to injury in direct proportion to their
general position and strength. The deep groovings of the bone for the
reception of the middle meningeal artery afford an additional source of
weakness to the bone in the squamo-temporal region. (See Fig. 50).
[Illustration: FIG. 29 A. THE BASE OF THE SKULL.]
[Illustration: FIG. 29 B. THE BASE OF THE SKULL AS SEEN ON
TRANSILLUMINATION.]
Further reference will be made to the relative strengths of the various
regions of the skull. Sufficient has been said to show that nature has
provided the skull with various paths by means of which forces applied
to the vault can be conducted and distributed to the base.
Before, however, proceeding to discuss the effects produced on the base
of the skull, it is necessary to add that nature provides other methods
by means of which the intensity of a blow, delivered over the vertex of
the skull, is diminished. The forces are broken up and distributed in
the following manner:--
1. Though the force tends to travel in the direction of the applied
force, yet the convexity of the skull allows of the dissemination of
that force over a large superficial area.
2. The intervention of cartilage or fibrous tissue between two or more
of the component bones of the vault tends to diminish the intensity of
the force, to break it up and to alter its direction.
3. The bony ridges, along which the forces tend to travel, themselves
terminate blindly (see Fig. 28). Thus,
(_a_) Forces passing from the frontal region converge, more or less, to
the crista galli.
(_b_) Forces from the external angular frontal process pass along the
wings of the sphenoid bone to the anterior clinoid process.
(_c_) Forces from the auditory region are projected along the summit of
the petrous bone towards the apex of that process and to the posterior
clinoid process.
(_d_) Forces applied to the occipital region travel inwards along the
internal occipital crest to the strengthened margins of the foramen
magnum, or are projected outwards along the lateral sinus ridges. In the
former case, the force either passes forwards towards the dorsum ephipii
and so again reaches the posterior clinoid process, or is directed more
laterally towards the jugular process of the occipital bone, there
meeting the fibrous tissue intervening between that process and the
corresponding part of the temporal bone.
4. All forces, whether transmitted along the internal occipital crest,
the temporal bone, the sphenoidal wings, or the crista galli of the
ethmoid, are further transmitted to the dura mater attached to those
prominences and ridges. The dura mater undoubtedly plays an important
part in the reception and transmission of the forces.
5. The forces all show a tendency to converge towards the pituitary
region, the great ‘water-cushion’ of the brain--a region bounded by the
clinoid processes. That these processes receive a considerable part of
the forces transmitted is confirmed by the fact that they are frequently
torn away from their basic attachments. This is especially the case with
respect to the attenuated base of the anterior clinoid process.
It is obvious, therefore, that forces tend to be transmitted from the
vault to the base, and yet the base is, in many respects, the weakest
part of the skull. It is perforated by numerous foramina, it is hollowed
out in places for the formation of air sinuses and for the reception of
the integral portions of the auditory apparatus. Furthermore, it
presents a more or less plane surface, one differing in all respects
from the marked convexity of the vault. Those forces, therefore, which
are received by the base of the skull are not subjected to that
diffusion which forms so conspicuous a feature in the case of the vault.
All these points tend to show that the base of the skull is more or less
unsuited for the reception of severe blows, direct or transmitted,
whilst, on the other hand, nature has taken into consideration and
provided fairly adequately against the dangers incident to vault
injuries.
It is not proposed at this stage to discuss further the relative
strength of vault and base. Points, other than those already enumerated,
will be brought forward in subsequent sections.
FRACTURES OF THE BASE OF THE SKULL
Fractures of the base of the skull are produced in two ways:--
1. By violence applied _directly_ to the base--perforating wounds of the
orbit, bullet-wounds through the mouth and base of skull, the driving
inwards of the bones of the face, the driving upwards of the condyle of
the jaw (the ‘knock-out’ blow of the pugilist), and, as the result of
heavy falls on to the feet or buttocks, the upward driving of the
condyles of the occipital bone.
2. By violence applied _indirectly_--blows applied directly to the vault
and transmitted to the base. This variety will be considered first as it
receives the greatest prominence in surgical textbooks. Various
explanatory theories have been advanced, of which the following are the
more important:--
(_a_) =Aran’s theory of irradiation.= This theory states that ‘fractures
of the base result as extensions from fractures of the vault, the
fracture following the shortest anatomical route to the base’. Although
this theory must be accepted as offering a satisfactory explanation for
the occurrence of a certain proportion of basic fractures, such, for
instance, as result from a blow applied directly to the vertex, it
certainly cannot be accepted as accounting for the great majority of
basic fractures. The theory was advanced on the hypothesis that basic
and vault fractures were necessarily co-existent. That combined lesions
of this nature are frequently in evidence is not to be doubted for one
instant. It is, however, ‘putting the cart before the horse’ to say that
the vault fracture is always the primary lesion. Such is by no means the
case.
(_b_) =The bursting and compression theories.= The skull is here
regarded as an highly elastic sphere, compression of which leads to
diminution in the diameter along the axis of greatest pressure, bulging
occurring in other diameters. The bulging exceeding the limits of
elasticity a fracture occurs, the line of fracture varying according to
the different features present. Thus, when the lines of fracture run
parallel to the direction of the compressing force the bone bursts open
along the convexity (bursting fractures), and when the lines of fracture
run at right angles to the direction of the compressing force a fracture
by compression is said to result (compression fractures).
These theories are based on experiments carried out on the cadaver, the
skull being enclosed in a tight-fitting box and subjected to pressure
sufficing to bring about a fracture. Undoubtedly, the head may be
compressed between two forces, as, for instance, when a person is
knocked down in the street, the vehicle passing over the head, or, as in
a case recently under my care, where a boy, hanging by his feet from the
side of a barge, was crushed between the barge and the wharf as the
vessel swung inwards with the tide. Cases of bilateral compression are,
however, of infrequent occurrence, the great majority of basic fractures
resulting from blows applied directly at the region of the level of the
base of the skull (see p. 76), or from the forward propulsion of the
body, the head coming into violent contact with a resisting object, as,
for instance, when a person is thrown out from a motor-car, the head
striking against a tree, brick wall, &c. In the first case, there can be
no question of bilateral compression, and in the second the compression
is exerted between the vertex and the occipital condyloid region.
Moreover, the fundamental points on which the bursting and compression
theories are grounded are based on erroneous principles. The skull
cannot in any sense be regarded as a sphere, nor does it possess the
requisite elasticity to bulge and allow of compression in the manner
that the theory demands. The skull, in reality, forms rather less than
two-thirds of a sphere, the base passing inwards from the lower limits
of this partial sphere in a more or less horizontal plane. This can be
readily verified by placing the skull on a table so that its base
corresponds to the surface of the table. The elastic properties of the
skull have also been greatly exaggerated, and far too little attention
has been paid to the peculiar anatomical formation of the base.
(_c_) =The contre-coup theories.= Fractures of the base occasionally
occur in which evidence is conclusive that the blow was received on the
vault, the vault itself remaining uninjured. Such cases have given
origin to this theory, one stating that ‘from the point struck a wave is
transmitted through the semi-fluid brain, producing a fracture at some
more distant point’. Helferich, for instance, maintains that isolated
fractures of the orbital roof, and more rarely of other parts of the
base, are produced by the influence of hydrostatic pressure. There can
be no question that waves are transmitted through the brain and
cerebro-spinal fluid, but that such waves should be capable of producing
a basic fracture is, in my opinion, beyond the bounds of possibility.
The theory is opposed to all my experience of basic fractures, and the
cases brought forward in support are capable of a much more probable
explanation. The base is undoubtedly the weakest part of the skull, and
a blow on the vault may fail to produce a local lesion and yet, when the
force is transmitted to the weaker base, may there bring about a more
definite result. For instance, it is by no means uncommon to find that a
blow on the frontal region fails to fracture the vertical plate of that
bone and yet suffices to produce a fracture, often comminuted, of the
orbital plate of the frontal bone or of the cribriform plate of the
ethmoid, two fragile plates, either of which may shatter like a plate of
glass from the effect of forces transmitted across them. In further
support of this theory, the following case, recently under my care, may
be cited. The patient received a heavy blow over the left occipital
region. A fracture passed inwards across the left cerebellar fossa
towards the posterior border of the foramen magnum, and a second
fracture, entirely distinct from the first, passed across the right
orbital plate of the frontal bone. In this case, the force conducted
across the base, from behind forwards, failed to fracture the strong
basi-occiput, but succeeded in producing a more definite lesion on
reaching the fragile orbital plate.
Some of the celebrated surgeons of the last century insisted that the
course pursued by basic fractures was to be explained on anatomical
grounds, but their views have been neglected and theories based on
experimental evidence have been accepted in their place. All
experiments, such as those previously mentioned, are useless, and
definite conclusions can only be gained by carrying out in every case
the following method of investigation: (1) by obtaining in the first
case an accurate history as to the manner in which the injury was
received; (2) by noting all visible and palpable signs of external
injury; (3) by careful observation of all the clinical symptoms during
the progress of the case; (4) by comparison of such with the lesions
found in case of death.
Over 300 cases have been investigated by me after these principles. In
about 30 per cent. of the cases sufficient evidence was obtained to show
that the basic fracture resulted and extended from a primary fracture of
the vault. These cases were to be explained by Aran’s theory of
irradiation. This theory, however, errs in stating further that the
fracture follows the shortest anatomical route to the base. This is not
correct, for the line of fracture corresponds to the direction of the
applied force and is influenced to a very large extent by the resistance
offered, the weaker areas being picked out and the strong buttresses
avoided. It is only in the most severe cases that the fracture travels
to and traverses across the base in such a direction as to show that,
for the time being, all laws are in abeyance.
In about 5 per cent. of cases the fracture resulted from bilateral
compression, from falls on to the buttocks, &c., and from blows applied
to the angle of the jaw. These cases afforded examples of the bursting
and compression theories.
On the other hand, in over 60 per cent. of cases, the injury was
received over one of the following situations: (1) in front, over the
frontal eminence or supra-orbital ridges; (2) in the antero-lateral
region, over the external angular frontal process; (3) in the lateral
region, over the lower temporal, auricular, and mastoid regions; (4) in
the posterior region, over the superior curved line of the occipital
bone or over the external occipital protuberance.
In all these cases, therefore, the blow was inflicted at or near the
level of the base of the skull, the resultant fracture being a fracture
by direct violence, the fracture traversing the base and splitting it
much in the same way as a chisel splits a board of wood. The ‘grain’ of
the wood may be regarded as representing the weaker basic lines, and any
‘knot’ the resistance offered by the strong basic buttresses, the forces
being momentarily turned aside, but soon again passing onwards, parallel
to the original direction, but not necessarily in the same straight
line.
[Illustration: FIG. 30. PLAN OF THE BASE OF THE SKULL. _a_, _a_, The
transverse pre-condyloid line; _a′_, _a′_, The line pursued, in whole or
in part, by the ‘typical’ basic fracture.]
Any blow delivered at or near the basic level tends _primarily to
involve the weaker area, the base, passing secondarily upwards on to the
vault_. One may go even so far as to say that in most combined vault and
basic fractures, the vault fracture is a secondary development, the
basic fracture being the primary lesion.
There is, however, still another important anatomical feature bearing
on the mechanism of basic fractures, one that must necessarily come into
force in the greater number of such fractures. The base of the skull may
be said to consist of two parts, one lying anterior to the condyles of
the occipital bone, the other posterior to and including the condyles
with their vertebral attachment. These two segments are united to one
another by a weak chain--represented by a line drawn from one external
auditory meatus to the other, with, as a connecting link, the sphenoidal
sinus in the middle line.
When the base of the skull is viewed from below, it will be seen that
the weak line includes both Glaserian fissures, both petro-sphenoidal
sutures, both foramina lacera media, with the sphenoidal sinus again as
a connecting link. The two parts of the skull are, to all intents and
purposes, merely cemented together by the union of the basi-sphenoid and
basi-occiput. Consequently, if a blow be received on the antero-lateral
region of the head, the anterior segment tends to be split off from the
more fixed posterior part, the fracture following the weak line
previously indicated. This weak line occupies so important a position in
the mechanism of basic fractures that careful observation will show that
the greater number of middle fossa fractures follow that line, wholly or
in part. Such a fracture of the middle fossa may be termed ‘the typical
fracture of the base of the skull’ (see Figs. 30, 34 and 39).
=Summary of theories.= Aran’s theory of irradiation, with certain
modifications, accounts satisfactorily for about 30 per cent. of basic
fractures.
The contre-coup theory may be rejected entirely.
The bursting and compression theories are unsatisfactory, accounting for
not more than about 5 per cent. of fractures.
The majority of cases result from direct violence applied at or near the
basic level, the fracture passing across the base in the general
direction of the applied force, but not necessarily in the same straight
line.
Up to this point certain facts and theories have been discussed, such as
bear on the general mechanism of basic fractures. It now remains to
consider other factors that exercise influence on the general direction
of the fracture.
=The influence of sutures on the line of the fracture.= Complete
maceration of the skull is always essential in endeavouring to estimate
in what way the various sutures of the skull influence the extent and
direction of a fracture. Sutural separation is generally regarded as of
infrequent occurrence. An examination of a large number of macerated
skulls has shown, however, that sutural separation is in reality of
common occurrence. Certain sutures show a special liability to such
changes, especially the masto-occipital, the petro-occipital, and the
petro-sphenoidal. Separation of the sutures is more common in the young
adult; in the infant and in the old such conditions are seldom observed.
Allusion has already been made to the fact that forces transmitted from
the vault to the base, or vice versa, undergo a marked diminution in
intensity when the sutures of the skull are encountered, the ‘fracture’
showing a marked disposition to follow the line of the suture. When the
force is excessive, all rules are temporarily in abeyance, but, under
ordinary circumstances, the separation along the line of a suture
corresponds fairly accurately with the dentations and serrations of the
suture involved. Sutural separation without actual fracture is a
possible occurrence, but is decidedly rare. Such isolated fractures are
confined, more or less, to the sagittal suture in the vault, and the
masto- and petro-occipital sutures in the base.
=The influence of air-sinuses, &c., on the line of the fracture.= The
_sphenoidal sinuses_, two in number, are usually separated from one
another by a thin septum. This septum is, however, often deficient, and
a single cavity exists. The sinuses make their appearance about the
seventh or eighth year; they vary greatly in size but, when fully
developed, occupy the greater part of the so-called body of the
sphenoid, extending backwards almost as far as the junction of the
basi-sphenoid and basi-occiput, and spreading outwards into the wings of
the sphenoid and over the roof of the orbit.
The sinus is bounded on all sides by a thin lamella of bone; its roof
forms part of the middle fossa of the skull, the sides are separated by
a thin bony wall from the cavernous venous sinus, and the floor aids in
the formation of the roof of the naso-pharynx. There exists, therefore,
in the very centre of the base of the skull--in the region of the
so-called buttress of connexion between the posterior and anterior
segments of the skull--an exceedingly weak area, one which must be
implicated in the great majority of basic fractures. The ‘weak line’ of
the base of the skull--previously referred to--is now still more
accentuated.
The sphenoidal sinus is involved in at least 40-50 per cent. of basic
fractures, comminution of the sinus wall being often so excessive that a
probe can be passed with the greatest ease from the middle fossa into
the naso-pharynx. Blood is thus allowed to escape readily into the
naso-pharynx, and a source is opened up for the possible development of
meningeal infection.
Reference to the various illustrations of fractures of the base will
supply further evidence as to the special liability of the sinus region
to injury. It will be seen that nearly all fractures that pass one
middle fossa to the other, or from one middle fossa to the opposite
anterior fossa, traverse this region.
The _frontal sinuses_, also two in number, are separated from one
another by a thin osseous septum. Up to the age of puberty these sinuses
are either absent or represented by a small cell. Subsequently, they
develop rapidly, often extending into the orbital roof. The upper and
inner boundary--usually very fragile--assists in the formation of the
anterior fossa of the skull. The outer boundary--the perpendicular plate
of the frontal bone--is much more dense, and, consequently, a fracture
of the outer wall is almost necessarily associated with a fracture
involving the inner or orbital boundary, that is to say with a fracture
of the anterior fossa.
_The ethmoid cells._ The ethmoid bone consists of a collection of cells
which communicate with the nasal cavity (middle and superior meati), and
which are merely separated from the anterior fossa of the skull by the
thin cribriform plate. This plate of bone is of so fragile a nature that
splintering occurs in the great majority of anterior fossa fractures.
The special dangers that arise from the possibility of meningeal
infection are obvious.
_The auditory region._ That part of the petrous bone which encloses the
auditory apparatus, and which transmits the seventh and eighth pair of
nerves, is proportionately weakened and correspondingly liable to
fracture. The special details of these fractures are dealt with on p.
102.
[Illustration: FIG. 31. TO ILLUSTRATE THE RELATION OF BASIC FRACTURES TO
CRANIAL NERVES.]
=The influence of basic foramina.= It has often been stated that a basic
fracture is arrested on meeting one of the larger foramina of the skull.
With this view I am not in agreement, for not only are the larger
foramina frequently involved, such as the foramen lacerum posterium and
medium, but the largest foramen of all, the foramen magnum, is often
implicated. It will be granted that certain foramina are but rarely
involved, but this is due to the fact that they are aside of the chosen
and definite paths of basic fracture. Thus, the foramen ovale and the
foramen spinosum are only exceptionally involved because they lie
immediately anterior to the petro-sphenoidal suture, whilst the anterior
condyloid foramen--transmitting the hypoglossal nerve--is rarely
implicated because it lies internal to the usual posterior fossa
fracture. On the other hand, the foramen lacerum medium is involved in
nearly every fracture that passes from one middle fossa to the other.
=The probable line of basic fracture in any given case.= When the
various weaker lines and areas are taken into consideration, and when
the direction and site of the applied force are known, one is generally
enabled to foretell with considerable accuracy the probable transbasic
course of the fracture. After investigating over 300 cases, I was
enabled to frame the following rules with respect to the probable line
of transbasic fracture.
_Direction, &c., of _Probable resultant basic fracture._
the applied force._
1. Force applied to The fracture passes backwards from the
the median frontal perpendicular plate of the frontal bone to the
region. cribriform plate of the ethmoid, thence between
the optic foramina to the body of the sphenoid,
the thin sinus roof being usually comminuted. From
there the fracture diverges to the opposite side,
and tearing off the posterior clinoid process,
passes along the petro-occipital suture to the
jugular foramen, being then continued on the other
side of that foramen along the masto-occipital
suture, and so again to the vault.
[Illustration: FIG. 32. DIAGRAM OF LINES PURSUED BY BASIC FRACTURES.
Force applied to the median frontal region.]
2. Force applied to The fracture passes across the anterior fossa
the lateral frontal towards the sphenoidal fissure, tearing away the
region, in the anterior clinoid process, and again comminutes the
situation of the roof of the sphenoidal sinus. Progressing onwards,
external angular with or without fracturing the posterior clinoid
frontal process. process, the fracture passes either along the
anterior part of the petrous bone at its junction
with the greater wing of the sphenoid towards the
opposite middle and external ears, or along the
petro-occipital suture to the jugular foramen, and
continued along the masto-occipital suture as in
the previous case.
[Illustration: FIG. 33. DIAGRAM OF LINES PURSUED BY BASIC FRACTURES.
Force applied to the lateral frontal region in the situation of the
external angular frontal process.]
3. Force applied to The fracture passes across the roof of the bony
the region of the auditory meatus towards the junction of the
external ear. anterior and inner walls of the middle ear, the
membrane undergoing a variable amount of
destruction and displacement. The fracture is then
continued across the tegmen tympani, and after
following the petro-sphenoidal suture reaches the
foramen lacerum medium, being again continued on
the opposite side of that foramen to the
sphenoidal body. Thence it pursues one of two
courses. Most commonly the fracture passes
backwards obliquely to the opposite middle and
external ears, following a course similar to that
already indicated.
In such cases the fracture may extend on each side
up on to the vault in such a manner that the two
segments are merely united by the soft parts;
whether the fracture be so complete or not, a more
minute examination of the line of separation will
evidence many interesting points. An inspection of
the anterior aspect of the posterior fragment
shows that the fracture passes just in front of
the geniculate ganglion of the facial nerve, the
ganglion being laid bare, whilst its petrosal
branches are usually torn. The fracture also
passes anterior to the Eustachian tube and the
horizontal part of the internal carotid artery. On
examining this posterior fragment the following
structures will be seen, passing from without
inwards: the posterior half of the external
auditory meatus, the mastoid antrum, the lacerated
membrane and the ossicles of the middle ear, the
geniculate ganglion of the facial nerve, the
Eustachian tube, the horizontal part of the
internal carotid artery, the Gasserian ganglion,
and the posterior half of the sphenoidal sinus in
the middle line (see also Fig. 39).
After reaching the sphenoidal body, the
alternative course for the fracture to pursue is
to pass towards the opposite sphenoidal fissure
and, tearing off the anterior clinoid process, to
be directed across the anterior fossa, parallel to
the original direction but not in the same
straight line.
[Illustration: FIG. 34. DIAGRAM OF LINES PURSUED BY BASIC FRACTURES.
Force applied to the region of the external ear. _a_ ... _a_, The
‘typical’ basic fracture (see also Fig. 30).]
4. Force applied to The fracture follows the occipito-mastoid suture
the mastoid region. to the jugular foramen, and is again continued on
the opposite side of that foramen along the
petro-occipital suture towards the apex of the
petrous bone. It then passes across the sphenoidal
body to the sphenoidal fissure of the opposite
side, and so across the anterior fossa. It is
especially common in this particular variety of
fracture to find fissures diverging from the
region of the sphenoidal sinus forwards towards
the cribriform plate of the ethmoid, these
fissures usually passing between the optic
foramina.
This fracture is also peculiar in so much that,
when the degree of separation along the
occipito-mastoid suture is excessive, there is
special liability to a tearing of the lateral
sinus wall as the sinus begins to turn downwards
and inwards.
[Illustration: FIG. 35. DIAGRAM OF LINES PURSUED BY BASIC FRACTURES.
Force applied to the mastoid region.]
5. Force applied to The fracture passes across the thin cerebellar
the lateral fossa and strikes the foramen magnum immediately
occipital region. behind the condyle. Starting again from a similar
point on the opposite side of the foramen, the
fracture passes outwards to the jugular foramen.
Again, two courses are now available, the fracture
either cutting outwards across the body of the
petrous, ‘external’ to the internal auditory
meatus and cutting across the facial nerve in the
region of the geniculate ganglion, and finally
terminating in the roof of the middle ear, or else
passing along the petro-occipital suture and so to
the foramen lacerum medium, the sphenoidal
fissure, and the anterior fossa as in the previous
case.
[Illustration: FIG. 36. DIAGRAM OF LINES PURSUED BY BASIC FRACTURES.
Force applied to the lateral occipital region.]
6. Force applied to The resultant fracture varies according to the
the posterior direction of the applied force. A force which is
occipital applied to the posterior occipital region at right
region. angles to the transverse axis of the skull results
in a fracture which, on reaching the posterior
margin of the foramen magnum, is continued again
on the opposite side of the foramen along the
dorsum ephipii. When the force is more oblique in
direction (as is usually the case) the fracture
traverses the thin cerebellar fossa to the outer
margin of the jugular foramen, and then follows
one of the two courses indicated in the previous
case.
More commonly the fracture cuts across the petrous
bone.
[Illustration: FIG. 37. DIAGRAM OF LINES PURSUED BY BASIC FRACTURES.
Force applied to the posterior occipital region, the fracture
following the course _a. a._ or _b. b._, according to the direction of
the applied force.]
=Summary.= Basic fractures tend to follow certain definite paths, this
transbasic course varying according to the direction of the force
applied and the site of application of the same. Whether the fracture
completely traverses the base depends on the character of the force and
the resistance offered, for bases, as well as vaults, vary greatly in
strength. To every rule there must be exceptions, and cases are at hand
in which the fracture appears to have obeyed no law, or in which the
force applied was of so forcible a nature that the fracture traversed
the base, regardless of all the ordinary rules.
The principles enumerated above were formulated by me some four years
ago, and, in spite of certain adverse criticisms, I am more than ever
convinced that the rules are correct, and that time and research are
alone required to add to the strength of my assertions.
SYMPTOMS RESULTING FROM FRACTURE OF THE BASE OF THE SKULL
The symptoms resulting from a fracture of the base of the skull vary
according to the particular fossa fractured. From a general point of
view, the following symptoms require consideration:--
Hæmorrhages.
Escape of cerebro-spinal fluid.
Escape of brain-matter.
Escape of air from the air-sinuses into the surrounding tissues.
Involvement of certain cranial nerves.
Symptoms pointing to fracture of the Anterior Fossa.
=Hæmorrhages=: (_a_) _Subconjunctival hæmorrhage_ usually makes its
appearance at the outer canthus of the eye, progressing inwards towards
the corneo-scleral margin, and, in the most severe cases, completely
surrounding the cornea, bulging the conjunctiva forwards in such a
manner as to constrict the field of vision. The extravasated blood is
usually bright red in colour, makes its appearance within a few hours of
the accident, and reaches its maximum within thirty-six to forty-eight
hours.
In some cases a condition of subconjunctival œdema (chemosis) is
observed. This also usually originates at the outer canthus.
Taken by themselves, neither hæmorrhage nor œdema are of any great
diagnostic value. Both conditions, however, aid materially in confirming
the diagnosis.
The blood is almost invariably completely absorbed, and no ill effects
remain.
(_b_) _Palpebral and peri-palpebral hæmorrhage_ is seen in most cases of
fracture of the anterior fossa. This form of hæmorrhage differs from the
one mentioned above in that it usually commences at the inner canthus of
the eye, thence progressing in the outward direction. The extravasated
blood may be wholly anterior to the suspensory ligaments of the lid, in
which case it may be surmised that the fracture only involves the
perpendicular plate of the frontal bone. More commonly, however, the
cribriform plate of the ethmoid shares in the lesion, in which case
palpebral, peri-palpebral, and subconjunctival hæmorrhage are all
present.
(_c_) _Orbital hæmorrhages_ may be so extensive that marked forward
protrusion of the globe exists. The time at which proptosis makes its
appearance, and the degree to which it progresses, vary according to the
nature of the lesion. Thus:--
Proptosis severe, appearing implies a fracture associated with
almost at once, injury to the cavernous sinus
or internal carotid artery.
Proptosis moderate, and „ a fracture involving the
appearing after a few hours, walls of the orbit, the blood
being derived from lacerated
ethmoidal and other small
vessels.
Proptosis appearing days or „ a fracture involving the
weeks after the accident, region of the sphenoidal body
usually progressive, and complicated by the
formation of a fistulous
communication between the
cavernous sinus and the
carotid artery (see Traumatic
orbital aneurysm).
(_d_) _Retinal hæmorrhages._ Fleming, in 1902, reported 12 cases of
fracture of the skull, all except one being fractures of the base, in
which retinal hæmorrhages were present. All cases were associated with
hæmorrhage into the subarachnoid space, and when this hæmorrhage was of
a unilateral nature the retinal changes were likewise one-sided. It was
also found that in 4 cases of cerebral hæmorrhage without osseous
lesion retinal hæmorrhages were present in three, these three being all
associated with considerable effusion into the subarachnoid space.
These observations are not only of value in the general diagnosis of
intracranial lesions, but are also of considerable importance in the
differential diagnosis between extra- and intradural hæmorrhages.
(_e_) _Hæmorrhage from the nose and mouth_ is almost invariably present
in fractures of the anterior fossa, with the inference that the fracture
involves the cribriform plate. The blood--derived mainly from lacerated
ethmoidal vessels--escapes from the anterior nares or, passing back into
the naso-pharynx, escapes by the mouth or is swallowed, to be vomited up
later.
=Escape of cerebro-spinal fluid.= Blandin, of the Hôtel-Dieu, drew
attention to this condition in the year 1840. The fracture involves the
cribriform plate of the ethmoid, and is associated with laceration of
the overlying dura mater and arachnoid, and of the prolongations of
those membranes along the olfactory nerves.
The escape of cerebro-spinal fluid from the nose may be regarded as
diagnostic of a fracture of the anterior fossa, in spite of the fact
that Goucard, Malgaigne, and others describe cases in which, as the
result of a severe fracture of the petrous bone (middle fossa) without
laceration of the membrana tympani, the fluid escaped along the
Eustachian tube to be expelled by mouth and nose.
At this stage, it will be necessary to allude more fully to the
general question of cerebro-spinal discharge from the nose, mouth, and
ear. The symptom is an important one, though undoubtedly of far less
frequent occurrence than stated in text-books. This was proved by
Crandon and Wilson, who reported 27 cases in which there was a
cerebro-spinal discharge out of a total number of 530 cases examined.
Phelps mentions 13 in a series of 286 cases of fractured base. My
experience coincides with these statements.
The escape of a slightly blood-stained fluid from the ear and nose
does not necessarily imply that the fluid is cerebro-spinal in nature,
for it has been proved on numerous occasions that fluid may escape in
considerable quantities without the existence of a basic fracture. In
such cases the fluid is derived either from the membranous labyrinth
(the liquor cotunnii) or from the mucous membrane lining the ear and
nose, the result of great vaso-motor dilatation of aural and nasal
vessels.
If the fluid be cerebro-spinal in nature, the natural inference is
that the subarachnoid space is opened up to the exterior, either
directly or indirectly along the course of a cranial nerve. A chemical
analysis of the fluid will determine the nature thereof, provided that
the fluid be collected EARLY.
Thus, cerebro-spinal fluid is whilst fluid derived from other
rich in chlorides, contains sources contains chlorides, a
little or no albumen, but fair amount of albumen, and no
shows a trace of a reducing sugar.
substance, allied to
pyro-catechin,
Certain factors, however, must be taken into consideration which
diminish the value of these chemical tests, for, though the fluid be
cerebro-spinal in nature, the admixture of blood at once interferes
with the delicacy of the test. Furthermore, even in the event of a
profuse discharge of cerebro-spinal fluid, the first part collected
alone contains sugar, the discharge soon becoming nothing more or less
than a serous exudation.
The fluid is almost certainly cerebro-spinal if the discharge begins
within twenty-four hours of the accident, if it be practically
colourless, fairly profuse, and continuing for two or three days,
perhaps longer.
Though the discharge usually originates early, cases are recorded in
which the flow commenced some weeks after the accident. The discharge
may continue for hours or for weeks. Sir W. Savory recorded a case in
which fluid escaped for one month from both ears. The quantity also
varies greatly, usually a few ounces, but sometimes many pints. Sir W.
MacCormac recorded a case in which 10 pints escaped within five hours.
A profuse discharge is due to the fact that, as the original
cerebro-spinal fluid drains away, its place in the subarachnoid space
is taken by a serous exudation from the cerebral venous system. This
exudation occurs as soon as the subarachnoid pressure is sufficiently
reduced, the serous exudation progressing till the venous and
cerebro-spinal pressures are again equal.
As regards the _prognosis_, it is interesting to note that the escape
of cerebro-spinal fluid implies of necessity that the subarachnoid
space is opened up to the exterior, with all attendant dangers of
meningeal infection, yet that the prognosis is generally favourable.
One might even go further and state that the prognosis in such cases
is rather more favourable than under more ordinary circumstances.
Thus, Battle records 36 cases with a mortality of 25 per cent., the
general mortality of fractured base being about 44 per cent. My own
experience tallies with these statistics. The more favourable result
hinges no doubt on the fact that the prolonged outflow tends to wash
away organisms existent in the aural and nasal passages.
With regard to any special points in treatment, it is obvious that
syringing of ear or nose is absolutely contra-indicated. The cavities
should be _lightly_ plugged with gauze, the dressings to be renewed as
soon as they are soaked. The patient must also be prevented from
interfering with the dressings.
With regard to the routine use of urotropin to guard against the
advent of meningitis, see p. 116.
=Escape of brain-matter from the nose.= This diagnostic symptom is of
very rare occurrence. For its development the following factors are
requisite:--
Great comminution and destruction of the anterior fossa.
Severe local laceration of the brain (frontal lobes).
A copious discharge of blood and cerebro-spinal fluid.
A general increase in the intracranial pressure.
One case only of this nature has come under my own observation, that of
a man whose right nostril was blocked with brain substance. He died
shortly after admission into the hospital, and at the post-mortem
examination the above conditions were found.
=Escape of air from the air-sinuses into the surrounding regions.= When
the fracture involves the frontal, ethmoidal, and mastoid sinuses, any
sudden increase of the intrasinus air-pressure, such as is caused by
sneezing, blowing of the nose, &c., may force air into the surrounding
tissues. A distinction must be made between those cases in which the
pericranium overlying the seat of fracture is torn and those in which it
remains intact. In the former case, the escaping air may spread widely
into the neighbouring loose tissues, leading to a condition of ‘surgical
emphysema’. In the second case, the air remains confined to a smaller
area, giving rise to a soft, more or less rounded swelling. Gentle
palpation of this swelling imparts to the fingers that crackling
sensation peculiar to the condition. Firm pressure results in diminution
in the size of the tumour, the contained air being forced back into the
sinus cavity. Such localized collections of air are known as
‘pneumatoceles’.
As regards the special _treatment_ of these conditions, the patient
must, in the first case, be warned against straining of all sorts.
Pneumatoceles require no other treatment. The condition soon disappears
if the patient recovers. In widespread surgical emphysema, an incision
should be made over the injured sinus, thus allowing of the direct
escape of the air expelled from that sinus.
=The involvement of nerves.= The following nerves may be involved in
anterior fossa fractures:--
(_a_) _The olfactory nerve._ The great majority of anterior fossa
fractures traverse the cribriform plate, necessarily injuring the fine
branches of the olfactory bulb. The bulb itself may be lacerated, with
or without injury to the under surface of the frontal lobes. Sir
Prescott Hewitt considered that anosmia, or loss of smell, resulted most
frequently from blows applied to the back of the head, the frontal
region being injured by contre-coup. From my own experience it would
appear, however, that anosmia, whether uni- or bilateral, whether
transient or permanent, generally results from direct injuries of the
cribriform plate with associated lacerations of the olfactory nerves. It
is difficult to estimate the presence or degree of immediate loss of
smell on account of the general condition of the patient and because the
nostrils are usually more or less filled with blood coagulum. Experience
shows, however, that early loss of smell is the rule and total and
permanent anosmia the exception. Anosmia is usually associated with some
degree of loss of taste.
(_b_) _The optic nerve._ Many cases have been recorded in which visual
defects resulted from blows applied to the head. The blindness may be
partial or complete, immediate in onset or developing at some future
date. In the latter case, the loss of vision is due to retinal changes
or results from post-neuritic atrophy.
The occurrence of complete or partial blindness as the immediate result
of the injury is, at first sight, difficult to explain, for the vast
majority of anterior fossa fractures avoid the immediate vicinity of the
optic foramina, passing by preference between the two foramina or
diverging towards the sphenoidal fissures. Small fissured fractures not
infrequently radiate through the optic foramina, usually, however, of so
slight a nature as to be incapable of leading to any gross lesion of the
optic nerves. Hæmorrhage into the sheath of the nerve is probably
responsible for a certain proportion of cases, more especially those in
which there is a peripheral concentric loss of vision, the more central
fibres escaping. It is possible, also, that cases evidencing temporal
or nasal blindness may be due, as J. J. Evans[17] thinks, to a
contre-coup contusion of the nerve through it being forcibly driven
against the bony boundaries of the foramen. Taking into consideration,
however, the very frequent presence of a fracture through the anterior
clinoid process (see p. 82), and the usual displacement of that process,
it would appear probable that immediate and more or less complete loss
of vision results from the compression and crushing of the optic nerve
by reason of the pressure exercised by a displaced clinoid process.
The following statistics add confirmation to this view. Thus, Callen
collected 17 cases in which the optic nerve was compressed by osseous
fragments in the region of the optic foramen, whilst Holder observed
injury to the bones entering into the formation of the foramen in 53 out
of 86 cases of fracture involving this region.
The prognosis varies according to the cause of the blindness. When
resulting from concussion of the nerve trunk or from hæmorrhage into its
sheath, certain fibres may regain their function. In the majority of
cases, however, that have come under my own observation, blindness of
the affected eye was immediate and permanent.
(_c_) _The nerves passing through the sphenoidal fissure._ The
ophthalmic division of the fifth nerve is rarely injured to such a
degree as to cause anæsthesia of all the regions supplied. Blood
extravasation into the surrounding regions, or direct involvement of one
of the branches of the nerve, often results in areas of anæsthesia, and
some few cases have been recorded in which there was complete anæsthesia
of both cornea and conjunctiva, with subsequent ulceration and
sloughing. The nasal nerve may be implicated as the result of a fracture
involving the cribriform plate, whilst the supra-orbital and
supra-trochlear branches may be damaged by fractures of the vertical
plate of the frontal bone.
The third nerve is similarly liable to injury, in any part of its
orbital course. It is quite exceptional, however, for the whole trunk to
be affected, some of the branches being taken, others left. The fourth
nerve is also occasionally involved, generally in association with other
orbital nerves.
When anæsthesia or paralysis of muscles results from pressure exercised
on the nerves by extravasated blood, the ultimate prognosis is not
unfavourable. When due to direct implication, in the line of the
fracture, the prognosis is much more uncertain, partial or complete loss
of function resulting.
SYMPTOMS POINTING TO FRACTURE OF THE MIDDLE FOSSA
=External hæmorrhages.= (_a_) _Hæmorrhage into the temporal region._ The
extravasated blood may either be confined to the temporal
region--temporal hæmatoma--or diffused throughout the subaponeurotic
space. A temporal hæmatoma is always highly suggestive of a fracture
involving the temporal fossa, especially in the event of marked outward
bulging, with stretching and discoloration of the overlying tissues. In
many cases also the hæmatoma pulsates, in which case it can be presumed
that the fracture of the temporal fossa is associated with hæmorrhage
from a lacerated middle meningeal artery (see Fig. 38). In such cases
the application of pressure to the hæmatoma may lead to the development
of fits on the contra-lateral side, originating in the face or arm
regions and spreading to the higher cortical motor area.
[Illustration: A
B
FIG. 38. TO ILLUSTRATE THE PROBABLE SOURCE OF PROFUSE HÆMORRHAGE FROM
THE EAR. A, The fracture the roof of the external auditory meatus. B,
Comminution of the tegmen tympani, the fracture involving the groove for
the posterior branch of the middle meningeal artery.]
(_b_) _Hæmorrhage from the ear and mouth._ The great majority of middle
fossa fractures involve the external auditory meatus, passing inwards
across the roof and floor of the middle ear towards the body of the
sphenoid. Examination will show that the fracture passes inwards towards
the junction of the inner and anterior walls of the middle ear, that is
to say, towards the tympanic orifice of the Eustachian tube. The
membrana tympani undergoes a variable degree of destruction. In the
lesser cases the membrane is torn in its upper and front part only--in
the region of the membrane of Shrapnell--whilst in the more serious
cases it may be completely destroyed. The blood that escapes from the
ear is derived from those vessels that supply the lining cuticle of the
external and middle ears, from the numerous tympanic vessels, from the
lateral sinus, and from the middle meningeal artery. The amount of blood
which escapes varies according to the source of the hæmorrhage. When
hæmorrhage occurs from the smaller vessels, the blood either clots in
the external meatus or trickles from the ear. In the most severe cases
the hæmorrhage is profuse and long-continued. Some years ago a case
came under my observation that threw light on the probable source of
such severe hæmorrhages.
A man was admitted into the hospital, suffering from profuse
hæmorrhage from the ear as the result of a fall down an area. The
bleeding continued for fourteen hours, soaking the dressings and
continuing so long as the man lived. At the post-mortem examination an
extensive comminution of the tegmen tympani was discovered, the
fracture being associated with great extra-dural extravasation of
blood from a lacerated middle meningeal artery. The extra-dural
hæmorrhage was enabled to escape through the tegmen tympani into the
middle ear, and thence by means of the lacerated membrana tympani (see
Fig. 38).
Profuse and long-continued hæmorrhage from the ear should always arouse
suspicion as to the possibility of injury to the middle meningeal
artery. Since meeting the case recounted above, many similar cases have
come under my care, and, in several instances, guided by this symptom
alone, operative measures have been carried out successfully.
The two following cases show, however, that the extra-dural
extravasation may be derived not only from the middle meningeal artery
but also from the lateral sinus.
‘A man fell down an area and suffered from continuous hæmorrhage from
the ear. He remained in bed for a few days, and then, becoming tired
of confinement, got up, walked some distance on a cold and frosty day,
and visited a _sage femme_. On returning home he complained of feeling
ill, the hæmorrhage from the ear ceased, and shortly afterwards he
became unconscious and died. The autopsy showed an extensive fracture
of the petrous bone with extensive extra-dural hæmorrhage from a torn
lateral sinus and from a lacerated meningeal artery.’[18]
The man had remained fairly well so long as the extra-dural blood was
permitted a free means of escape through the tegmen tympani and
external auditory meatus, but, so soon as clotting occurred,
compression symptoms developed and the man died in that condition.
‘A man, 50 years of age, fell down, striking his head against the
kerb. On admission it was seen that blood was trickling freely through
a torn membrana tympani. He rapidly became unconscious and died. The
post-mortem examination revealed a fracture involving the middle ear
and external auditory meatus, passing backwards across the lateral
sinus, in which region there was a large extra-dural extravasation of
blood.’[19]
The above statements are confirmed by Dwight,[20] who, in 146 autopsies,
found that, in 69 per cent. cases of fracture of the middle fossa of the
skull, there was bleeding from the ear, and that in 29 per cent. cases
the fracture was associated with laceration of branches of the middle
meningeal artery.
Although hæmorrhage from the external auditory meatus may be regarded as
almost diagnostic of a middle fossa fracture, especially of that variety
previously described as the ‘typical basic fracture’, yet the blood may
be derived from a torn membrana tympani or from laceration of the lining
cuticle of the external meatus. Aural examination will soon prove
whether the blood is coming through a rent in the membrane, in which
case the diagnosis is clear. Sometimes bleeding takes place from both
ears, a symptom practically diagnostic of the transverse middle fossa
fracture known as the ‘typical basic fracture’.
The following statistics will supply further information as to the
relative frequency with which hæmorrhage occurs from ears, nose, and
mouth, and the proportionate mortality. The cases were collected and
tabulated by Crandon and Wilson.
-------------------------+--------+--------+-------+-------------
|_Cases._|_Lived._|_Died._|_Mortality._
-------------------------+--------+--------+-------+-------------
Hæmorrhage from the ear | 281 | 170 | 111 | 39 per cent.
Hæmorrhage from both ears| 47 | 16 | 31 | 66 per cent.
Hæmorrhage from the nose | 44 | 17 | 27 | 61 per cent.
Hæmorrhage from the mouth| 168 | 73 | 93 | 33 per cent.
-------------------------+--------+--------+-------+-------------
_Special points in prognosis and treatment._ It is not possible to
formulate any very definite prognosis when the hæmorrhage takes place
from one ear only, though the mortality is about 40 per cent. When
bleeding takes place from both ears the outlook is more grave, the
mortality being about 66 per cent.
With regard to special treatment, two points are obvious: (1) that
syringing of the ear is absolutely contra-indicated, on the ground that
such treatment carries with it a considerable risk of bringing about
meningeal infection; and (2) that plugging the external meatus with
strips of gauze is an unsurgical form of treatment, insomuch as the
escape of blood from the ear is an important factor in preventing
compression of the brain, more especially in those cases where
hæmorrhage is profuse. Under the last named conditions, operative
measures--exploration for a torn meningeal artery or lacerated venous
sinus--are to be carried out.
Hæmorrhage from the mouth may be slight or copious, according to the
source from which the blood is derived. In the former case, the bleeding
takes place from sphenoidal and pharyngeal vessels, in the latter from
the cavernous sinus or from the internal carotid artery (see p. 148),
the bone being shattered in the region of the sphenoidal body, with
comminution of the walls of the contained air-sinus.
=Escape of cerebro-spinal fluid.= This condition was first investigated
by Van der Wiel in 1727, and more completely by Langier in 1839. The
majority of those middle fossa fractures which involve the petrous
portion of the temporal bone pass immediately anterior to the genu of
the facial nerve (see p. 102), and it follows, therefore, that the
fracture cannot so involve the dural and arachnoid prolongations of that
nerve in such a manner as to allow of the escape of cerebro-spinal
fluid. This fact probably explains another fact, namely, that aural
cerebro-spinal discharge is an infrequent symptom in middle fossa
fractures. On the other hand, as a result of blows applied to the
occipital region, a fracture originating in the posterior fossa may cut
across the petrous bone, almost at right angles, in such a manner as to
sever the seventh nerve in the region of the genu (see Fig. 41). This is
the usual nature of a basic fracture associated with the escape of
cerebro-spinal fluid from the external auditory meatus. More rarely,
this particular class of fracture is unaccompanied by any injury to the
tympanic membrane, in which case the fluid may escape along the
Eustachian tube into the nose and naso-pharynx (see p. 91).
Cerebro-spinal fluid may also escape from the nose and mouth in middle
fossa fractures in the event of extensive injury to the basi-sphenoid
with involvement of the overlying cisterna basalis. The following case
exemplifies that condition:--
A man suffered from a severe fracture of the middle fossa. Three weeks
later there was a sudden and profuse discharge of cerebro-spinal fluid
from the nose. Meningitis developed and the patient died. The
basi-sphenoid was extensively comminuted, the overlying membranes
torn, whilst a probe could be passed readily from the cranial cavity
into the naso-pharynx.
_Special points in prognosis and treatment._ The question of
cerebro-spinal discharges has been discussed previously (see p. 91). It
is therefore merely necessary to lay further stress on the fact that
syringing of the ear is absolutely contra-indicated, for reasons already
stated. The ear should be cleaned out with wool and gauze and _lightly_
packed with strips of gauze, these to be renewed when soaked with fluid.
When the cerebro-spinal discharge is long continued, acute eczema of the
side of the neck may develop as a result of the irritating effect of the
fluid. Under these circumstances it is advisable to adopt precautionary
measures, painting the skin with ‘new skin’ or collodion. Ointments are
of but little use. The eczema will clear up so soon as the discharge
ceases.
=Escape of brain-matter.= The conditions needful for the discharge of
brain-matter from ear or nose have been enumerated previously (see p.
93). There are but few cases recorded in literature, and one case only
has come under my own observation:--
A lad, 11 years of age, fell some distance out of window on to his
head. He was admitted under the care of my colleague, Mr. Lockwood. On
admission he was unconscious, and was bleeding freely from the right
ear and nose. Shortly afterwards it was noticed that brain-matter was
issuing from the right external auditory meatus, sufficient
brain-matter being obtained to fill a teaspoon. The extensive nature
of the brain-injury was confirmed by the fact that the left arm and
leg were paralysed for some days. On the fourth day the boy regained
consciousness and recognized his relations. From this period onwards
he made an uninterrupted recovery. I have seen the lad on various
occasions, the last time one year after the accident. At that time he
was an exceedingly bright and intellectual boy.
_Special points in treatment and prognosis._ The brain-matter should be
gently wiped away from the ear, and the meatus cleansed and lightly
plugged with gauze. Operative measures are required in the event of the
development of symptoms pointing to brain compression. The prognosis
must necessarily be unfavourable, but, as the conditions are almost
entirely confined to the young, the most astonishing recoveries are
reported.
=Involvement of nerves.= The second and third divisions of the fifth
nerve pass respectively through the foramen ovale and the foramen
rotundum, two foramina which lie anterior to the petro-sphenoidal
suture, a suture traversed by the majority of middle fossa fractures.
These two nerves are therefore seldom involved.
In all the cases of fractured base which have come under my observation
I have never seen the foramen rotundum implicated, and in one case only
was the foramen ovale involved.
In certain rare instances, a fracture, passing in the antero-posterior
direction, may cut across the apex of the petrous bone in close relation
to the cavum Meckelii--the bed of the Gasserian ganglion--in which case
all three terminal divisions of the fifth nerve may suffer. Thus, a
case was reported by Lee in 1853 in which, seven weeks after the
accident, the following symptoms were present:--anæsthesia of the left
face and forehead, anterior two-thirds of tongue, and left nostril,
together with weakness of the left masticating muscles, and an opaque
left cornea.
_The sixth nerve._ The sixth nerve may be involved either by itself or
in conjunction with other cranial nerves. In the latter case the paresis
is due to blood extravasated in the sphenoidal fissure or in the orbital
cavity. In the former case the nerve is injured where it grooves the
lateral aspect of the dorsum ephipii, a process frequently fractured in
lesions of the middle fossa. Fractures tend to pass obliquely across
this process, one nerve usually escaping. The prognosis as to functional
recovery is very problematical.
_The seventh and eighth nerves._ There can be no doubt that the seventh
nerve, on account of its complicated intrapetrous course, is more
frequently involved than any other cranial nerve. Köhler records 22
cases in 48 middle fossa fractures. My own experience coincides closely
with Köhler’s, facial paresis or paralysis being noted in nearly 50 per
cent. cases of middle fossa fracture.
The question of facial nerve implication is so intimately associated
with involvement of the eighth nerve that the two subjects must be
considered together. Thus, cases may be classified as follows:--
1. Cases of paresis of the facial nerve with a variable degree of
deafness.
2. Cases of complete facial paralysis with complete deafness.
The greater number of middle fossa fractures involve the middle and
external ears, as is evidenced, amongst other symptoms, by hæmorrhage
from the ear. Some degree of facial paralysis is frequently existent,
not always evident at first sight, but requiring careful examination and
comparison between the two sides of the face. The fracture involves both
roof and floor of the external ear and passes inwards towards the
junction of anterior and inner walls of the middle ear, the membrana
tympani undergoing a variable degree of destruction whilst the ossicles
may also be injured. Thence, the fracture passes inwards towards the
petro-sphenoidal suture in such a manner that the geniculate ganglion
of the facial nerve is exposed and laid bare on the anterior aspect of
the posterior portion of the skull.
The facial nerve, therefore, escapes direct injury except in so far that
the ganglion may be compressed by blood-clot or fragments of bone.
Partial loss of function results. In most cases the blood is absorbed
and a complete recovery may be anticipated. The degree of deafness is
directly proportionate to the damage incurred by the membrana tympani
and ossicles.
[Illustration: FIG. 39. TO SHOW THE RELATION OF A TYPICAL BASIC FRACTURE
TO THE MIDDLE EAR AND ITS ADJUNCTS. A, Malleus; B, Middle ear and
aditus; C, Geniculate ganglion (facial nerve); D, Groove for great
superficial petrosal nerve; E, Canal for tensor tympani muscle; F,
Processus cochleariformis; G, Eustachian tube; H, External auditory
meatus; I, Membrana tympani; J, Mastoid cells.]
In the second group of cases a different picture is obtained. Usually
the result of blows applied to the occipital region, the fracture
traverses the thin cerebellar fossa towards the outer angle of the
jugular foramen, thence cutting across the petrous bone, external to the
internal auditory meatus, and terminating, usually by comminution, in
the tegmen tympani. It is in the transpetrous part of the fracture that
the damage is done, for, not only is the facial nerve cut across in the
region of the ganglion, but the auditory apparatus is also severed into
two parts. The exact line of the fracture is shown in Figs. 40 and 41.
[Illustration: A
B
FIG. 40. TO SHOW THE RELATION OF BASIC FRACTURES TO THE PETROUS BONE. A,
The basic fracture, resulting from a force applied to the left occipital
region, follows the course depicted in Fig. 36. B, The inner half of the
petrous bone, being loose, is thrown forward so as to show the relation
of the fracture to the integral parts of the petrous bone.]
In this class of fracture, though facial paralysis and deafness are both
immediate in onset and permanent in duration, there is, in many cases,
no bleeding from the ear as the membrana tympani may be uninjured.
The facial nerve may also be implicated in that rare type of basic
fracture which was described by Lèon Boullet in 1878, under the title of
‘Fracture of the Mastoid portion of the Temporal bone’. This fracture is
fully described on p. 108. It will suffice to mention that the mastoid
process may be torn away from the base of the skull, the facial nerve
being lacerated as it descends the aqueductus Fallopii.
Bilateral facial paralysis is exceedingly rare. Two cases were described
by the late Professor von Bergmann. Its occurrence is pathognomonic of
the typical basic fracture (see p. 84).
[Illustration: A
B
FIG. 41. TO SHOW THE RELATION OF BASIC FRACTURES TO THE PETROUS BONE. A
shows the course pursued by an antero-posterior fracture of the petrous
bone. Note that it lies external to the internal auditory meatus. B
shows--enlarged--the inner aspect of the outer fragment. Note the
relation of the fracture to the semicircular canals, and that the
membrana tympani and ossicles are quite uninjured.]
_Complete facial paralysis may be associated with the following
symptoms_:--
Epiphora, conjunctivitis, and keratitis (from paralysis of the
orbicularis palpebrarum).
Loss of taste (from involvement of the chorda tympani).
Impaired nasal air-entry (from paralysis of dilator alæ muscle).
Impaired acoustic sensibility (from paralysis of the stapedius).
Impaired mastication (from involvement of the buccinator muscle).
Impaired secretion of saliva (from the cutting off of the secretory and
vaso-dilator fibres of the chorda tympani).
Lastly, it is necessary to add that facial paralysis developing some
days or weeks after the accident, though sometimes dependent on
degeneration of nerve-fibres as the result of pressure in the region of
the geniculate ganglion, may also arise from an ascending neuritis or
from meningeal infection.
SYMPTOMS POINTING TO FRACTURE OF THE POSTERIOR FOSSA
=External hæmorrhages.= In fractures of the posterior fossa, blood
effused into the deeper tissues of the scalp has considerable difficulty
in coming to the surface and thus making itself evident. Furthermore,
the resistance offered by the nuchal muscles tends to confine the blood
to the subtentorial region, thus adding to the already grave prognosis
of fractures in this region. On careful palpation, however, it will be
noted that the nuchal tissues present a doughy or boggy condition,
whilst ecchymosis becomes evident after twenty-four to thirty-six hours.
A peculiar ecchymotic patch is occasionally observed, appearing in front
of the mastoid process and travelling upwards in a curved direction,
concavity forwards, following the outline of the ear. It is said to
result from the tracking of blood along the course of the posterior
auricular artery. Whether this is the case or not, the hæmorrhage
usually implies a separation along the line of the masto-occipital
suture.
=Escape of cerebro-spinal fluid.= } Neither of these symptoms
=Escape of brain-matter.= } are present.
=Involvement of nerves.= When dealing with fractures of the middle
fossa, allusion was made to the implication of the seventh and eighth
pair of nerves as the result of a fracture traversing the posterior
fossa of the skull towards the outer angle of the jugular foramen and
cutting across the petrous bone (see p. 104).
The ninth, tenth, and eleventh cranial nerves may be injured in the same
variety of fracture. These three nerves are, however, so protected by
their dural sheaths that they generally escape injury.[21]
In the following cases the nerves were involved:--
The patient was admitted suffering from a fracture resulting from a
blow on the posterior parietal region. During the next four days no
special symptoms developed. On the fifth day, during a sudden attack
of dyspnœa and dysphagia, death occurred. A fissured fracture was
found which extended into the jugular foramen, a region occupied by
blood-clot.
A man committed suicide by means of a pistol-bullet fired through the
mouth. The bullet lodged against the under surface of the petrous
bone, tearing the jugular vein and lacerating the nerves passing
through that foramen.
In another case the patient was admitted with a fractured base. He
progressed favourably until the tenth day when, on sitting up suddenly
in bed, he was seized with rigors, dyspnœa, and dysphagia, dying
shortly afterwards. A basic fracture was found, practically dividing
the skull into two parts and involving the jugular foramen.
Displacement had occurred with consequent compression of the ninth,
tenth, and eleventh nerves.
_The twelfth nerve._ The anterior condyloid foramen is most favourably
situated with respect to the course pursued by posterior fossa
fractures. No instance of its involvement has come under my own
observation.
Stierlein records a case in which the tenth and twelfth nerves were
injured, with inability to speak or swallow, paralysis of the right half
of the tongue, soft palate, vocal cords and pharyngeal constrictions.
Death resulted in seven weeks.
The late Professor von Bergmann[22] mentions a case of hypoglossal
paralysis together with paralysis of the sterno-mastoid and trapezius
muscles (eleventh nerve).
For _treatment_ of basic fractures, see p. 116.
FRACTURE OF THE BASE OF THE SKULL: SUMMARY OF SYMPTOMS
----------------------+----------------------+----------------------
_Anterior Fossa._ | _Middle Fossa._ | _Posterior Fossa._
----------------------+----------------------+----------------------
_Hæmorrhages._ | _Hæmorrhages._ | _Hæmorrhages._
Subconjunctival. | Into the temporal | Into the nuchal
Palpebral. | region. | region.
Peripalpebral. | From the mouth. | Into the occipital
Orbital. | From the nose. | region.
Retinal. | From the ear. | Into the
From the nose. | | post-auricular
From the mouth. | | region.
| |
_Cerebro-spinal | _Cerebro-spinal | _Cerebro-spinal
fluid._ | fluid._ | fluid._
From the nose. | From the nose. | None.
From the mouth. | From the mouth. |
| From the ear. |
| |
_Brain-matter._ | _Brain-matter._ | _Brain-matter._
From the nose. | From the ear. | None.
| |
_Air-escape._ | _Air-escape._ | _Air-escape._
From the frontal | From the mastoid | From the mastoid
sinus. | antrum. | antrum.
From the ethmoidal | |
cells. | |
| |
_Nerve-involvement._ | _Nerve-involvement._ | _Nerve-involvement._
Olfactory. | Fifth (second and | Seventh.
Optic. | third divisions). | Eighth.
Third. | Sixth. | Ninth.
Fourth. | Seventh. | Tenth.
Fifth (first | Eighth. | Eleventh.
division). | | Twelfth (?).
Sixth. | |
----------------------+----------------------+----------------------
FRACTURE OF THE MASTOID PORTION OF THE TEMPORAL BONE
Fractures limited to this region are of rare occurrence. Our knowledge
of the condition is obtained from the researches of Lèon Boullet, who
first described the fracture in 1876, reporting at the same time 26
cases.
The fracture usually results from sharp blows delivered along the
posterior border of the mastoid process, the force acting obliquely from
above downwards and forwards. More rarely, the process is detached as
the result of a blow delivered immediately above the ear, that organ
sharing in the displacement. In either case the detachment is usually of
an incomplete nature, mainly on account of the muscular and pericranial
attachments in the region involved.
According to Boullet, the following symptoms result:--
=Surgical emphysema and pneumatocele.= Air escapes from the mastoid
cells and antrum into the overlying tissues, either spreading widely
through the subaponeurotic space of the scalp and cellular tissues of
the neck (surgical emphysema), or remaining localized and forming a
tumour of inconsiderable size (pneumatocele). In either case palpation
reveals that peculiar crepitation which is pathognomonic of tumours of
this nature.
=Bleeding from the ear.= Hæmorrhage takes place into the middle ear,
and, as the tympanic membrane is usually lacerated, the blood escapes
from the external ear. In the event of the tympanic membrane being
uninjured, the blood may escape along the Eustachian tube into the
naso-pharynx.
Boullet also pointed out that certain complications may be associated
with the mastoid lesion. These are as follows:--
_Immediate._ _Remote._
Wound of the lateral sinus. Deafness.
Laceration of dura and brain. Otitis media.
Injury to the aqueductus Fallopii Caries and necrosis of the
and paralysis of the petrous bone.
seventh nerve.
=Treatment.= The displacement of the mastoid process is of so incomplete
a nature that the question of replacement by open operation seldom
arises. In the event, however, of intracranial complications, operative
treatment must be carried out. Under ordinary circumstances the
treatment consists mainly in the prevention of suppuration. When
suppuration occurs, frequent cleansing of the ear must be carried out in
order to prevent accumulation of pus in middle ear and antrum. This
object is to be attained, not by syringing, but by gentle irrigation and
light packing. Later on it may become necessary to carry out the
complete mastoid operation.
FRACTURES OF THE VAULT OF THE SKULL
Fractures of the vault of the skull may be restricted to the vault or
associated with a basic fracture. Evidence has been brought forward
previously to show that many vault fractures may be regarded as mere
upward extension from a primary basic lesion. The limitation of a
fracture to the vault depends on the nature of the productive force, the
degree of violence used, the site of application, and the direction of
the force. Thus, the smaller the weapon, the greater the violence, the
nearer the site of application to the vertex, the more direct the blow,
the greater is the tendency to vault limitation. Again, compound
fractures are much more liable to vault limitation than simple
fractures, as is proved, for instance, by the reports of Sir Prescott
Hewitt--20 compound fractures in which the fracture was restricted to
the vault of the skull, and 56 simple fractures in which the base was
involved in all but one.
Fractures of the vault may involve:--
(_a_) the external table only;
(_b_) the internal table alone;
(_c_) the whole thickness of the skull.
=Fractures of the external table alone.= These fractures are excessively
rare. Their existence was even doubted till the recent South African
War, when Makins[23] saw one case of this nature. They appear to be due
to the impact of a glancing bullet (see p. 297). A ‘gutter-shaped’
depression results, the comminuted fragments of the external table being
carried away or distributed in the region of the lacerated scalp (see
Chapter IX).
=Fractures of the internal table alone.= Ambrose Paré drew attention to
this class of fracture in 1652, but it remained for Teevan to
investigate more fully the condition in 1865. Previous to Teevan’s
investigations, it had been considered that the internal table of the
skull was the more brittle, and that fractures confined to the internal
table were to be explained on that hypothesis. Teevan, however,
demonstrated the incorrectness of such a theory, for, on firing bullets
through the skull, from without inwards and from within outwards, it was
found that on all occasions the more distal table suffered the more
severely. This was explained in the following manner:--the fracture of
the proximal table was produced by the bullet, whilst that of the distal
table resulted, not from the passage of the bullet alone, but also from
various fragments of bone driven along with the bullet.
Teevan’s experiments also proved that a fracture of the internal table
alone could be produced mechanically, this being in obedience to the law
that ‘when a pressure is applied to a body the fracture commences on the
line of extension, not that of compression’.
Fractures of the internal table are undoubtedly more common in those
situations where diploic tissue is prevalent, e.g. in the frontal,
parietal, and upper occipital regions. In the squamo-temporal and
cerebellar regions fractures of the internal table are almost unknown.
Teevan also stated that ‘but little force is required to produce such a
fracture, and that they are produced usually by some small body, such as
a stone’.
=Fractures involving the whole thickness of the skull.= Fractures which
involve the whole thickness of the skull may be:--
(_a_) Simple or compound.
(_b_) With or without depression.
When depressed, the fragments of bone may be either loose or
interlocked, forming in the latter case the so-called pond and gutter
fractures.
(_c_) Elevated, usually from sabre-cuts.
(_d_) Fissured, stellate, comminuted, punctured, &c.
(_e_) Explosive.
=Symptoms associated with fracture of the vault.= A diagnosis of
fracture of the vault is made:--
On the evidence obtained by local examination.
On the evidence supplied by symptoms dependent on injury to the
intracranial contents.
The various intracranial lesions are discussed elsewhere (see Chapters
III and IV).
=Evidence supplied by local examination.= A compound fracture will be
most readily determined by digital examination, previous to which the
scalp-wound must be carefully cleansed. Digital examination is greatly
preferable to investigation with the aid of the probe. In any case care
must be taken to avoid mistaking one of the sutures of the skull for a
fissured fracture.
In simple fractures the diagnosis is frequently obscured by an extensive
subaponeurotic or subpericranial hæmatoma. Irregularities of surface are
more or less diagnostic of a solution in the surface of the bone, and a
linear hæmatoma is of corresponding clinical value. In any case, the
presence of an extensive hæmatoma must be regarded as of so suggestive a
nature that exploration is called for, more especially when prolonged
concussion or compression are co-existent. Such treatment is imperative
when the hæmatoma--whether diffuse, localized, or linear--pulsates, such
a condition implying a breach in the surface of both bone and dura with
communication between the extra-cranial and some intra-cranial
hæmorrhage.
Pringle[24] lays stress on the value of percussion as an aid to
diagnosis.
‘The patient’s head must be supported beneath the occiput, the mouth
either open or shut--it matters not, so long as it is the same
throughout the examination--and the skull is struck sharply with the
finger. When a fracture is present, two changes in note may be
elicited. Either a note lowered in pitch over the fracture zone, or,
in addition, a definite crack-pot sound. The note elicited is most
typical when comminution is present, and some fragments loose. A
fracture of a T or L or V-shape gives the best crack-pot sound, and
the crack quality is always most pronounced when the percussing finger
comes over the angular portion of the bone. Hæmorrhage into the
subaponeurotic region blurs the note.’
[Illustration: FIG. 42. A COMMINUTED FRACTURE OF THE SKULL.]
If time and occasion permit, an X-ray photograph will clinch the matter.
When the fracture involves the internal table alone, the symptoms are
less definite. Teevan stated that this class of fracture does not lead
to the development of any symptoms unless:--
The middle meningeal artery be injured.
The dura mater and brain be irritated.
The brain be compressed.
He also adds that the existence of the following features suggests the
nature of the injury:--
The history of a slight blow, probably with a small body.
The blow situated over the parietal region.
[Illustration: A
B
FIG. 43. AN EXPLOSIVE FRACTURE OF THE VAULT OF THE SKULL. A shows the
right side of the skull and the site of entry of the bullet. B shows the
extension of the fracture round the left half of the skull. In the left
upper parietal region (Fig. B) a fissured fracture is seen where the
bullet failed to perforate the skull.]
Chronic fixed pain, some days or weeks afterwards, with symptoms of
brain-irritation or encephalitis, and even suppuration, suggesting
irritation of the meninges and brain by spicules of bone.
Compression and paralysis on the opposite side of the body some hours
afterwards, as the result of injury to the middle meningeal artery.
Symptoms of compression early and slight, combined with partial
paralysis of the opposite side of the body.
‘The less definite the symptoms of compression, the greater the reason
to believe that they are caused by the internal table only.’
Before entering into the question of _treatment_ of fractures of the
skull, it is essential that allusion should be made to the _temperature
in its relation to head-injuries._ The great importance of temperature
changes in the consideration of operative treatment will be manifest
when discussing the treatment of fractures of the base.
=The temperature in its relation to head-injuries.= The various
temperature changes observed in cases of head-injury have afforded a
subject prolific in discussion. Broca, Battle, Guyon, Walsham, and
others have endeavoured to deduce facts from the examination of head
cases, but the results have been rather indefinite. In over 300 cases
that have come under my observation, accurate records of the temperature
charts were obtained, the patients were watched throughout their
illness, and in the case of death, the autopsies were attended.
The following deductions were made:--
1. That, for a variable period of time after the injury, the temperature
is always subnormal--sometimes so low that it cannot be registered. This
is the period of shock.
2. That the patient may die in this state of shock, but that, if he
lives, reaction takes place and the temperature rises.
3. That this rise in temperature is, in fatal cases, rapid and
progressive. In one case the temperature rose 6° in seven hours, in
another 8° in four hours. Death occurs when the temperature is at its
highest--anything up to 106°, and even more when registered in the
rectum.
4. That the temperature may rise to a moderate height, and there ‘mark
time’. This is the ‘crisis’ of the case. A subsequent fall in
temperature generally indicates recovery, a further rise usually points
to a fatal termination.
5. That the rise of temperature is independent of any special osseous
lesion, since similar changes are observed in fractures of the vault and
in fractures of the base.
6. That laceration of the brain is present in the majority of cases in
which marked temperature changes are observed, but that the changes in
temperature are totally independent of any special regional
brain-injury.
Richet arrives at the conclusion that two hypotheses present themselves,
accounting for temperature changes in general: (1) that there are
certain temperature regulators in the encephalon which, when excited,
become stimulated in function; (2) that the cortical injury acts in a
sort of reflex manner on the regulatory centres situated in the pons or
bulb.
Attention was also drawn to the experiments of Lorin and van Benedin,
who, after excising the two cerebral hemispheres of a pigeon, showed
that the heat regulatory centre was preserved intact, proving that the
corpus striatum is not necessarily the head-office for heat-regulation
in general.
Till, therefore, more evidence comes to hand with respect to
heat-regulation in general, one cannot go beyond the broad statement
that, in severe head-injuries, definite temperature changes occur, that
the changes are independent of any special lesion of bone or brain, that
they are generally associated with some brain-injury, and that they are
probably due to the influence exerted by the lesion on the
heat-regulating centres in the region of the pons and bulb.
With regard to the value of the temperature, both with respect to
prognosis and treatment, a very much more definite statement can be
made.
First with respect to the =prognosis=. All cases of head-injury may be
grouped into four classes, according to the changes of temperature
present.
_Group 1._ The temperature, at first subnormal, undergoes a rapid and
progressive rise. Prognosis most unfavourable.
_Group 2._ The temperature, at first subnormal, rises gradually to 101°
or 102° and there ‘marks time’. This hesitancy marks the crisis of the
case, further elevation indicating a fatal result, whilst a fall offers
every hope of recovery.
_Group 3._ The temperature, at first subnormal, rises to normal and
remains at that level. Prognosis very favourable.
_Group 4._ The temperature, at first subnormal, remains subnormal. The
condition of shock persists, and the prognosis is most unfavourable.
Practically all cases of head-injury fall readily into one or other of
these four groups, and the temperature chart presents so clear a picture
that it must be regarded as of the greatest possible value in estimating
the prognosis in any given case. In other words, the temperature chart
affords an almost infallible guide both to prognosis and treatment.
With respect to alteration in temperature on the two sides of the body,
the clinical value of such changes must, from my own observations, be
regarded as of a very indefinite nature.
It now remains to discuss the value of temperature changes with respect
to treatment.
=Treatment of Fracture of the Base of the Skull.= In the earlier
paragraphs of this chapter the special treatment of aural and nasal
hæmorrhages and cerebro-spinal discharge was discussed, and some
allusion was made to the necessity of exploring the middle fossa in
cases of profuse arterial or venous aural bleeding. The general
treatment of basic fractures now requires description, previous to
which, however, space must be made for a short account of the routine
treatment by Urotropin--as advised by Crowe and Cushing--as a
prophylactic against the development of meningeal infection. The
following is a summary of Crowe’s paper[25] on the ‘excretion of
Urotropin in the cerebro-spinal fluid and its therapeutic value in
meningitis’.
1. Urotropin, when given by the mouth, invariably appears in the
cerebro-spinal fluid.
2. The largest amount of Urotropin is present in the cerebro-spinal
fluid from thirty minutes to an hour after the ingestion of the drug.
3. After doses of Urotropin, within therapeutic limits, a sufficient
amount of the drug appears in the cerebro-spinal fluid to exercise a
decided inhibitory effect on the growth of organisms inoculated into
this fluid after its removal from the body.
4. Following a subdural inoculation of dogs and rabbits with
streptococcus, 60-80 grains of Urotropin a day, given under conditions
which insure absorption, will markedly defer, and in some cases prevent,
the onset of a fatal meningitis.
5. In view of these observations, the prompt administration of Urotropin
is advised in all clinical cases in which meningitis is a possible or
threatened complication, or even when meningeal infection has actually
occurred.
[Illustration: FIG. 44. A TEMPERATURE CHART ILLUSTRATING THE CHANGES IN
TEMPERATURE OBSERVED IN HEAD-INJURIES.
(For description, see text.)]
Acting on these suggestions, I am accustomed to treat all head cases
with this drug, 10-20 grains three times a day by mouth. It may be given
per rectum, though probably with less satisfactory results. Traumatic
cases are treated as soon as possible, other cases receive their dose
for two or three days previous to the operation, the drug being
continued till all fear of possible meningeal infection has vanished.
In discussing the general treatment of basic fractures, it must be
accepted that the basic fracture in itself requires no treatment. Danger
or death is dependent on intracranial complications, and an
uncomplicated basic fracture demands no active surgical treatment. The
special treatment applicable to cases complicated by hæmorrhages, both
external to and beneath the dura mater, is discussed in the next
chapter. It is therefore only necessary to enter into those cases of
fractured base which are associated with concussion, irritation, and
compression of the brain--in other words, the _average_ case of fracture
of the base of the skull.
The surgeon must always be guided by the general condition of the
patient--the blood-pressure, character of pulse, state of respiration,
depth of unconsciousness, &c.--but, in my opinion, the temperature chart
affords perhaps the most valuable basis on which rules can be formulated
guiding the surgeon in his general line of treatment.
Thus (1) =when the temperature remains subnormal= the patient is in a
condition of severe cerebral shock, due, in the majority of cases, to
contusion or laceration of the brain, the grosser lesion being most
commonly situated either at the apex of the temporo-sphenoidal lobe or
at the anterior inferior part of the frontal lobe. The patient is,
however, suffering from shock, and the treatment advocated for that
condition in general is equally applicable to these cases in particular.
The patient should be placed in the so-called head-down position, and
the extremities firmly bandaged from below upwards. The vaso-motor
depression should be combated by the administration of rectal or
intra-venous infusions of saline solution, to each pint of which is
added 1 drachm of a 1 in 1,000 solution of Adrenalin Chloride. It is at
once obvious that, whilst combating the condition of shock, this mode of
treatment may tend at the same time to encourage fresh bleeding if the
brain should have been lacerated, or if intracranial vessels should
have been torn. For this reason I regard rectal infusion as the more
safe of the two methods, in spite of the fact that intra-venous infusion
brings about a more rapid improvement in the patient’s condition. The
effect of the infusion must be carefully observed, and as soon as the
blood-pressure rises and the temperature shows a tendency to rise--say
from the subnormal to the normal--the infusion process must be stopped,
and the further progress of the case observed.
The risks attendant on this mode of treatment are obvious, but in their
consideration, it must also be borne in mind that if the patient remains
in the collapse stage, without evidencing any sign of reaction, he will
inevitably die. If the treatment advocated should tide the patient over
this stage and induce a definite reaction, as exemplified by rise of
blood-pressure and elevation of temperature, the further treatment of
the case can be considered under the next group.
(2) =When the temperature rises progressively= the patient evidences
symptoms pointing to compression of the brain--coma, slow pulse, noisy
and stertorous respiration, hot skin and turgid face. Later on, as a
result of the increasing pressure, the medullary centres begin to show
signs of exhaustion, the pulse-rate increasing, and the respiration
becoming Cheyne-Stokes in character.