giving off its fibres to the lateral reticular processes of the cord,
{895} whence—whether interrupted by cells (Von Monakow) or not—they
probably reach the great cells in the gray substance from which the
anterior rootlets spring. The direct fasciculus probably terminates in
a similar way, and perhaps makes good, as it were, its failure to
participate in the gross decussation at the level of the foramen
magnum by decussating in detail along its entire length. It is usually
exhausted before the lumbar cord is reached, whereas the crossed tract
in the lateral column continues down as low as the origin of the
sacral nerves. A destructive lesion anywhere in the course of the
pyramid tract, whether it be in the motor area of the cortex, in the
loop of Rolando, in the internal capsule, the pons, or the cord
itself, will provoke descending degeneration; that is, sclerosis of so
much of the tract as lies below the lesion. Thus such degeneration is
found with porencephalic defect of the motor area. I found it in a
paretic dement who had extensive cortical destruction following a
submeningeal hemorrhage. It has been observed after focal lesion of
the pons (Homén, Schrader), and after transverse lesions of the cord,
either myelitic, traumatic, or as the result of compression by
vertebral disease. As a rule, the cells in the anterior horn are not
involved, and some observers question whether this ever occurs. I have
never found such involvement, although in its gross dimensions the
anterior horn as a whole appears atrophied. This atrophy I have been
able to account for satisfactorily by the disappearance of many of the
fibres which run into the gray substance from the reticular processes.
While the distribution of degeneration in the cord is rather uniform,
varying only in harmony with the ascertained individual variations in
the relative preponderance of the crossed and uncrossed parts of the
pyramid tract, there is much more variation in the cerebral
distribution of the degeneration according to the extent of the
original lesion. Thus, if the entire capsule be destroyed, the greater
part of the crus is involved. If only the posterior division in its
anterior part be destroyed, the degeneration is in the crus, limited
to that part which runs a subpial course on the crural demi-cylinder,
occupying from a fifth to a third of its surface-area. Still more
limited degenerations are described, but as yet are too few in number
to base other than tentative conclusions on them. Among these is one
occupying a thin strip on the inner side of the crus, which
degenerates after lesions near the genu of the capsule, and probably
represents the tract which governs the cranial nerve-nuclei. An
excellent observation by Von Mannkopf shows that the course of the
motor fasciculus is subject to some individual variation even within
the capsule.
A number of forms of secondary degeneration are described, involving
intracerebral tracts, such as those connecting the cerebrum and
cerebellum. The degeneration of the visual tract, from the optic nerve
to the occipital lobe, observed by Richter and Von Monakow, with some
conflict of opinion between these observers, is often as perfectly
demonstrative of the course of the optic fasciculi as degeneration of
the pyramid tract is demonstrative of the course of the voluntary
innervation of the muscles moving the limbs.
The secondary degenerations following lesion of the pons varolii are
acquiring special interest in view of their relation to special
nerve-tracts of the spinal cord of hitherto unknown function. The
purest instance {896} of an isolated degeneration of other than the
pyramid tract is the case illustrated in the accompanying diagrams. It
involved the interolivary layer, was both ascending and descending,
being traced above into the subthalamic region, and below decussating
into the opposite side of the oblongata, to terminate in the nuclei of
the columns of Burdach and Goll. The leading symptom manifested by the
patient was a hemiplegia of the muscular sense.[156]
[Footnote 156: Besides my case, others have been recorded by Homén,
Meyer (Strassburg), and Schrader, which are impure. In the former and
latter degeneration of the pyramid tract, in the second degeneration
of the olivary fasciculus, coexisted. It is not generally known that
Westphal, in one of the first volumes of the _Archives_ now edited by
him, found an ascending degeneration of the same tract for a short
distance.]
[Illustration: FIG. 35. Secondary Degeneration of Interolivary Layer,
Caudal or Descending Portion: A, in caudal half of pons; B, cephalic
end of oblongata; C, middle of oblongata; D, at level of so-called
upper pyramidal or interolivary decussation; E, at level of true
pyramidal decussation. The atrophy in this level has entirely crossed
the middle line; in D it is seen in the act of crossing.]
Ascending degeneration is found in a very distinct form after
compression of the cauda equina. It is limited to the posterior
columns, occupying nearly the entire area of the latter in the lumbar
cord, particularly the triangular field of Burdach's column mentioned
in the article on Tabes. In the dorsal and cervical cord it is limited
to the columns of Goll, and terminates in the clava of the oblongata
at the nuclei of those columns.
Higher lesions produce the same ascending degeneration of the column
of Goll, and in addition involve other, probably centripetal, tracts
which happen to be injured at their origin or in their course. For
example, a transverse lesion of the dorsal cord would produce
ascending degeneration for its whole length of the column of Goll and
of the direct cerebellar tract. In addition, it would, in obedience to
the law previously stated, produce descending degeneration of the
pyramid tract. This combination is almost a typical sequence of
compression myelitis of the cord, as {897} well as of ordinary
transverse sclerosis. Recently, Gowers[157] has described a secondary
degeneration in such a case of transverse lesion not previously
noticed. It is found in cases showing gross disturbance of cutaneous
sensibility, and occupies a narrow belt encircling the anterior
quarter of the circumference of the crossed-pyramid tract. It is
continuous, in my opinion, with a tract which in the upper cervical
cord is situated in a corresponding situation, and which degenerated a
short distance caudad in a case of secondary degeneration of the
olivary fasciculus described by Meyer, and in which similar sensory
symptoms were noted.
[Footnote 157: _Diseases of the Spinal Cord_, and _Neurologisches
Centralblatt_, 1886.]
[Illustration: FIG. 36. Decussating Degeneration of Interolivary
Layer: _Dr_, _Darc_, the crossing degenerated fasciculi; _Arc_, the
undegenerated fasciculi, after emerging from the partly sclerosed
raphé.]
CLINICAL HISTORY.—Secondary degenerations are passive results of other
more active processes, and few clinical signs are attributable to
them. The most important of these is the contracture which is found in
old hemiplegias, and attributed, like the secondary exaggeration of
deep reflexes in such, to the descending degeneration of the pyramid
tract. Bouchard believed that it was the retraction of the sclerotic
strand which acted as an irritant on the neighboring fibres. The
development of spastic symptoms in amyotrophic lateral sclerosis and
in focal lesions of the crossed-pyramid tract is in favor of this
view. On the other hand, the occurrence of flaccid hemiplegia, and its
conservation for years after the most extensive lesions, is against
it, as it is in these very cases that the secondary degeneration is
most intense. That the retraction of a {898} longitudinal strand
exercises any serious effect on neighboring and parallel fasciculi is
questionable, as the process is slow. There is, however, one situation
where such influence is very likely to occur—the decussations of the
oblongata. In the case already referred to, the retracting sclerosing
bundles undoubtedly must have exercised a damaging effect on their
fellows of the opposite side, which, interdigitating with them, were
compelled to pass through the sclerosing tissue. It has occurred to me
that the slight sclerosis which is sometimes observed in the
crossed-pyramid tract of the same side of a cerebral lesion, even
where that lesion is strictly unilateral, is due to a similar
influence. I think it can be shown that such sclerosis cannot be
traced to the primary lesion; it begins at the decussation, and it is
more than probable that the firm constriction to which the healthy
fibres are subjected in crossing through their shrinking fellows of
the opposite side is not alone the cause of the symmetrical yet
slighter lesion, but also accounts for the observation by Pitrés and
Charcot of a slight motor weakness observed on the same side as the
hemiplegia, producing lesion in ordinary cases of capsular
hemorrhage.[158]
[Footnote 158: Some of the French observers claim that this occurs
only in the early period, but a careful study of the matter by R.
Friedländer shows that the weakness of the side not usually regarded
as involved is found in the later periods, and well marked then
(_Neurologisches Centralblatt_, June 1, 1886).]
The PROGNOSIS and TREATMENT of secondary degenerations are practically
involved in the primary lesion which gave rise to them. The
contractures attributed to secondary sclerosis of the motor tracts is
to be treated on the principles mentioned in the following section.
The Treatment of Spinal Sclerosis.
As the histological character of the different forms of sclerosis is
similar—at least in the terminal period—the causes producing them
identical even in name, and the indications furnished by leading
symptoms analogous if not identical, the treatment of these various
disorders is naturally based on the same leading principles. There are
two objects to be aimed at in dealing with these chronic disorders:
The first is the cure or arrest of the morbid process itself; the
second is the amelioration of distressing and disabling symptoms.
It is generally recognized that a perfect cure of a sclerosis is a
consummation never to be realized by any plan of treatment now at our
disposal. The experiments of Kahler and others have shown that spinal
tissue, once destroyed, is not regenerated. The post-mortem
examination of cases of tabes which were considered as cured during
life (Schultze) has shown that the sclerosis had not been removed; the
process had merely become quiescent, and the apparent recovery had
been due to the vicarization of other nerve-elements than those
destroyed for the latter.
But if attempts at the regeneration of destroyed fibres and cells are
to be regarded as futile, the arrest of the destructive process is to
be considered as an object which offers better chances of realization,
and which is worth attempting for other than merely conservative
reasons. In a number of the forms of sclerosis described, notably in
tabes and the disseminated form, it is remarked that the
axis-cylinders lying within the {899} morbid district are in part
intact and in part but slightly affected. Here and there groups of
nerve-tubes may be found which retain even their myelin. While subject
to the vicissitudes inseparable from their position in the midst of
active pathological changes, these channels of nerve-force, though
anatomically patent, may have their function perverted or destroyed,
just as a nerve outside of the cord may be paralyzed by pressure or
anæmia though its structure be intact. Should the active phase of the
sclerotic process be arrested, these intact or nearly intact fibres
will resume their function, and thus an apparent improvement will be
effected. The spontaneous ameliorations in the course of tabes
dorsalis and the less marked ones of diffuse sclerosis, coupled with
temporarily improved sensation in the former and improved motion in
the latter disease, show that retrogressions of this character are
possible and do occur. How is the physician to imitate the action of
nature? how to intensify it so as to secure the permanent improvement
which nature unaided does not grant? The first factor to be considered
is the removal of the cause of the disease. A number of cases are due
to exposure to wet and cold and to over-exertion. Such exposure and
over-exertion, if not already rendered impossible by the disease, is
to be discontinued. A large number of cases of tabes—according to many
authors, a majority—a considerable number of cases of diffuse
sclerosis, and not a few of other forms, are connected with the
syphilitic dyscrasia. Here, at the very outset, we have a definite
indication for treatment, and while we may be disappointed in the
results of such treatment in a large proportion of cases, yet enough
of well-assured and substantial success has been and is obtained to
render it almost a matter of duty for the physician to try
antisyphilitic measures in every such instance.
The mixed treatment in chronic spinal disorders should be followed out
for long periods and faithfully. Most tabic and other sclerotic
subjects affected with constitutional syphilis are in what is called
the tertiary period of that disease, when iodide of potassium is less
useful than mercury. I have never gained anything by pushing either
drug to the extreme point in advanced cases, and it should be borne in
mind that mercurialization carried too far may itself prove directly
injurious to the nerve-centres.[159] In cases where gastric crises,
gross ataxia, muscular atrophy, and bladder disturbance have been of
long duration this treatment is rarely successful.[160] But in the
initial and early periods of tabes and in diffuse sclerosis of slight
intensity the effect is sometimes gratifying, and of such a nature
that it cannot be attributed to a coincidence with spontaneous
remissions of the disease. In one case both knee-jerks and the
pupillary reflexes returned, to disappear on premature discontinuance
of the treatment; and on resumption one knee-jerk again returned, and
has remained demonstrable now over half a year. In a second case the
fulminating pains and the bladder disturbance disappeared, a slight
indication of the pupillary reflex developed, and the patient has
remained stationary with this gain for a period of three {900}
years.[161] In a third case, one of established ataxia, with which
luetic osseous lesions occurred, the pupillary reflex has returned
twice, disappearing after the first reappearance. In one case of
combined sclerosis in which no syphilitic antecedents could be found
the paresis of the arms has disappeared, and the ataxic paresis of the
lower extremities has improved to such an extent that the patient can
stand with his eyes closed and his feet together, and on one leg with
the eyes open—feats which a year ago he was unable to perform. None of
the changes in symptoms taking place in these cases occur
spontaneously in sclerotic spinal disorders, and they must be
attributed to the treatment. Such treatment is best carried out in
conjunction with warm bathing. The Hot Springs of Arkansas, those at
Las Vegas, New Mexico, and the baths of Aix-la-Chapelle in Europe
enjoy a special reputation in this field. The springs of Arkansas, as
regards the intrinsic character of the water, possess advantages which
are probably not excelled by any European baths, but the therapeutical
management[162] is far from that ideal point of development attained,
for example, at Aix-la-Chapelle.
[Footnote 159: Mendel thus found in his experiments made on dogs,
developing cerebral disease from rotation with the head directed
toward the axis of rotation, that dogs who had previously received
subcutaneous injections of corrosive sublimate showed an increased
vulnerability to the action of the rotary apparatus.]
[Footnote 160: A remarkable exception is related in the section on
Chronic Myelitis.]
[Footnote 161: There was concentric limitation of all color-fields,
and only central perception of green; to-day, if anything, the
color-fields of this patient are a little greater than in the
physiological average. The case was undoubtedly one of initial tabes.]
[Footnote 162: Mercurial ointment is used by the hundredweight, to
quote the expression of a patient, and in certain establishments the
sufferers from the common taint plaster each other from head to foot,
as with mud, with this panacea for most of those ills which flock to
the springs. Still, there seems to be no doubt that enormous
quantities of mercury are borne well by those who use the baths, and
who under other circumstances are susceptible to its most undesirable
effects.]
Optic-nerve atrophy, according to the best authorities, constitutes a
contraindication to the use of mercury in any form. It may be laid
down as a general rule that the more rapidly the symptoms indicating a
sclerotic process are developed, and the more recent its advent, the
more energetically should the treatment be pushed. Mercurial
inunctions and the so-called heroic doses of iodide are to be
employed. But in cases progressing slowly and of long antecedent
history what may be called a dilute plan is more apt to yield good
results. Small doses of mercury,[163] given steadily for years, and
iodide of potassium, administered in well-tolerated doses for periods
of ten days, alternating with corresponding periods of intermission,
have, in my opinion, delayed or arrested the progress of tabes and
other forms of sclerosis for the long periods referred to in the
preceding sections.[164] Although the antisyphilitic measures adopted
in sclerosis of syphilitic origin are the most important, and the
prognosis of no such case can be regarded as hopeless as to recovery
or duration until they have been tried, other procedures, detailed
under the head of Peripheral Treatment, should not be neglected. While
some very severe cases improve rapidly on antisyphilitic treatment,
other much less severe and more recent cases, in which the same cause
is assigned with equal reason, are not affected by it in the slightest
visible degree. The reason for this difference is unknown, but it
necessitates the bearing in mind that by {901} limiting the treatment
to the etiological indication valuable time may be wasted in which the
symptomatic indications could be profitably followed.
[Footnote 163: The tablet triturates of biniodide of mercury or
corrosive sublimate furnished by Fraser & Co. of New York I have found
peculiarly useful; one one-hundredth or more of a grain may be thus
administered every two to four hours.]
[Footnote 164: I am now employing the same treatment in some cases
showing no syphilitic history. If any medicinal measures can act upon
connective-tissue proliferation, it is these very ones.]
In cases of sclerosis due to other causes than syphilis a number of
medicinal agents have been recommended as calculated to affect the
central disease directly. Ergot is recommended in sclerotic troubles,
particularly tabes, by a large number of writers. It is admitted that
this substance can produce tabes itself, so that its administration in
the large doses recommended by some is not without its possible
dangers. I have seen a patient well advanced in the disease who had
received the drug for three weeks consecutively in such
quantities[165] that on estimates made I came to the conclusion that
he had received more than some of the persons in whom Tuczek
discovered the development of ergotin tabes. Favorable results are
reported ensuing after its use in the early stages, particularly where
signs of irritation preponderated, such as lightning-like pains,
hyperæsthesia, and frequent erections; and it has been suggested that
the beneficial action is due to an effect on the blood-vessels, which
are supposed to be congested in the beginning of the disease. Proof of
such congestion has not been furnished: the vessels are usually
sclerosed and their lumen narrowed. In view of the undeniable danger
which attends the administration of ergot in tabes, it may be properly
insisted that its indications be more precisely formulated than has
yet been done. It is commonly noticed in the natural progress of tabes
that the lightning-like pains disappear, usually about the time the
anæsthesia becomes greater. The anatomical parallel is supposed to be
the destruction of the nerve-tubes whose previous irritation caused
these pains. If, as is claimed—and it seems to be
substantiated—ergotin does produce amelioration of the lightning-like
pains, it would prove a damaging revelation which showed that it did
so in imitation of the natural process; that is, by increasing the
sclerosis.
[Footnote 165: An expert ophthalmoscopist found that the retinal
vessels, which were somewhat dilated in this patient, were not
influenced by the treatment.]
The first drug to which an influence was assigned upon the sclerotic
processes, and which has maintained its reputation longest, is nitrate
of silver.[166] Its claim to being regarded as a remedy may be best
characterized by the fact that an author who is far from being
prejudiced against it, and who recognizes the claims of Wunderlich,
its advocate, speaks of it as a valuable placebo.[167] I have never
obtained any effects from this drug in the scleroses, or from the
chloride of gold, which has been also recommended for these
affections, nor have I seen any in cases where either or both had been
faithfully tried by others for years. The same is to be said of the
chloride of barium, which has been warmly extolled on the basis of a
very limited trial in disseminated and diffuse sclerosis.
[Footnote 166: One of the first patients on whom Wunderlich tried this
drug died while I studied at Leipzig. He had extensive argyria and
sclerosis of the posterior columns.]
[Footnote 167: Leyden, _op. cit._, vol. ii. p. 359.]
The direct application of the galvanic current to the spine is
recommended, more particularly by Erb and Neftel.[168] I am unable to
state {902} anything regarding currents derived from as many as twenty
of Siemens cells and applied in the ascending direction, as the latter
recommends beyond an experience which occurred in the practice of a
colleague, who, alarmed by the event to be related, referred the
patient subjected to this treatment to me. The patient suffered from
tabes dorsalis, the symptoms being limited to the lower extremities,
the ulnar distribution, and the pupils. The belt was in the lower
thoracic region; the ataxia and lightning-like pains were not great.
After a single application of an ascending current from twenty-two
cells, continued for ten minutes, the patient suddenly felt a severe
dull pain in the occiput and terrible lancinating pains in the
distribution of the occipital nerves. With this there occurred
scintillation before the eyes, and at the subsequent examination I
found that the belt sensation had moved into the neck. The coincidence
was so close, and sudden changes in the distributional area of tabic
symptoms are otherwise so uncommon, that I attributed the observed
change to the treatment.
[Footnote 168: In describing a case in which this measure not only
ameliorated lancinating pains and vesical symptoms, but also, applied
to the head, relieved the diplopia—usually a spontaneous occurrence,
according to both American and European writers—this writer takes
occasion to state that in the year 1869 tabes dorsalis was practically
unknown to American physicians (_Archiv für Psychiatrie_, xii. p.
619). Duchenne described progressive locomotor ataxia in that and the
preceding year; the necessity of referring to the unfamiliarity of
American physicians with a disease not at the time recognized on
either side of the Atlantic is hence not apparent. Leyden (_op. cit._,
vol. ii. p. 325) candidly admits that the German medical profession
was at first averse to recognizing Duchenne's limitation: this
reproach cannot be laid at the door of American physicians, as I can
distinctly recollect the demonstration of several well-marked cases
exhibiting the characteristic symptoms then known, in the year 1870.
The disease obtained recognition in American textbooks and journals as
early as in those of any other land.]