must depend largely upon the cause. When the disorder depends upon a
catarrh, we may expect that the trouble will disappear, or at least be
mitigated, as the local affection is relieved. If of syphilitic or
rheumatic origin, it should disappear pari passu with the primary
disease. So far as we know, there is no danger to life, the loss of
voice being the only important result.
The DIAGNOSIS is easy. The laryngoscope will enable the observer to
differentiate it from all other affections by which the voice is
destroyed. It is possible that disease affecting the articulation of
the arytenoids, and thus preventing their movement, might give rise to
a doubt. A careful examination in such cases will, however, generally
reveal the fact of tumefaction or other evidence of structural change.
Closely allied to the paralyses which we have just been considering are
the affections of the glottis of hysterical origin.
If the cases of true paralysis of the lateral crico-arytenoid muscles
are rare, it is equally true that a partial arrest of the action of
these muscles, and temporary for the most part in duration, is not
unfrequently met with. The etiology of these cases seems to be much
more within our knowledge than that of those of which we have just been
speaking; at least the conditions under which they occur are much
better known. For the most part they occur in females. They are met
with in patients of nervous temperament, generally adults, though I
have seen one case in which the subject was still undeveloped. There
are very generally the evidences of hysteria in some of its various
manifestations. We may therefore assume that the disease is functional
in its nature and that it is reflex in origin. It has been said that,
as it is not dependent upon any disease of the muscles or nerves of the
larynx, so far as we know, it should not be classed among the
paralyses. For the same reason it should not be considered as a
neurosis of the organ, but of the system in general. But it is a
neurosis of the larynx, and therefore ought to be placed here. In
addition to this, it is in its symptoms identical with or very similar
to the true paralyses dependent upon alteration of the nerves or of the
muscles of the part.
The etiology of the affection has already been suggested in the
definition. A disturbance of the functions of the uterus, or possibly
of other portions of the nervous system, may be so reflected as to
materially interfere with the action of the muscles of the larynx. It
is possible that the affection may occur in males, as other troubles
called hysterical sometimes do. That the uterus is not always the
source of the reflex disturbance is certain. I have very recently seen
a case in which there was unquestionably an intermittent partial
paralysis of the adductors of the muscles in an adult man. It seemed to
be dependent upon the condition of the stomach. Whenever there was
flatulence or an accumulation of gases in the stomach, the voice became
husky, requiring great effort and expenditure of air in phonation, and
then extinct. Examination with the laryngoscope showed the cords in the
condition of adduction. In the effort to speak there was a very slight
approximation of the vocal bands, but not enough to admit of their
vibration. With the recovery from the disorder of the stomach this
condition disappeared. I have seen one other case similar in character.
I think we may therefore assume that the trouble can be produced by any
affection which creates a disturbance of the pneumogastrics, and which
by reflex action interferes with the proper functions of the spinal
accessory.
The disease is always bilateral. Its advent is generally sudden. The
symptoms are first and almost solely loss of voice. The aphonia may
from the beginning be persistent, or there may be intervals when the
patient speaks with ease. In some cases the patient is able to whisper;
in others this power is also lost: in the effort to phonate there is
absolutely no sound. There is {84} no pain, but there is often cough:
this cough is hoarse, like that which has been described under a
previous heading. The general health is in some cases apparently
perfect, but in a majority of instances there will be found some
disturbance of the viscera of the abdomen. Perhaps in all cases this is
true, but so slight that we are obliged to look carefully in order to
find it. Upon inspection with the laryngoscope the cords are seen to be
separated, but not so widely as in complete paralysis of the adductors
from other causes. There is no marked morbid condition of the mucous
surfaces. The secretions are not affected. It is possible that there
may be at the same time a partial paralysis of the pharyngeal muscles,
so that there is also dysphagia. In a few instances there is a
paræsthesia of the parts above. The dysphonia or aphonia is then
associated with a feeling as though there was a foreign body in the
throat. In efforts at phonation the cords usually move slightly toward
the median line, but not enough to enter into vibration. When this
condition of things is observed, and there is no other cause for the
explanation of the loss of voice, we may with safety assume that we
have to do with an hysterical paralysis of the adductors.
The duration of this form of motor disturbance is uncertain. It may
terminate suddenly after a short duration or it may continue
indefinitely. It is a cause neither of dyspnoea nor asphyxia. It always
ends finally in recovery. This statement is possibly subject to an
exception in cases in which there are other diseases present and when
these diseases are of themselves dangerous to life.
The pathology and morbid anatomy are dependent upon the length of time
during which the muscles have been in a state of inaction. It is
possible that the muscles may degenerate or lose their power to act
with the normal vigor, or there may be a simple atrophy of the muscles,
as in a case reported by Mackenzie. So far as I know, this alteration
of the muscles is very seldom found in hysterical paralysis. When
degeneration or atrophy does exist, it is probably a result, and not a
cause, of the paralysis. So far as we know, there is no antecedent
change in the larynx. This must of necessity be the case, since the
disease is reflex, and not primarily in the organ of speech. Why the
morbid influences are manifested in this organ to the exclusion of
others we do not know. In fact, we do not know that this is the case.
So far as we can judge from the records of similar cases found in the
literature of the subject, we may safely believe that there is in
nearly all of the patients some other disorders of motility, but the
derangements of speech are so striking that these have masked all minor
troubles.
The intimate relation between the organs of expression, of which speech
is one of the most important, finds in these cases a striking
illustration. The quality of the voice is modified by emotion. The
evident relation of the generative functions to this psychical state is
well known. This fact explains the association of these troubles so
frequently encountered in the study of the morbid conditions of the
larynx. It is true that the disturbance is not always limited to the
phonators, but it is nevertheless more frequently met with in these
muscles than in the muscles of respiration. Emotion and the expression
of emotion go together. Their morbid conditions are therefore
associated.
Paralysis of the Arytenoideus--Central Adductor.
The function of this muscle is to approximate the arytenoid cartilages.
Its paralysis leaves the posterior borders of the cartilages separated,
even though the vocal processes are by the action of the lateral
crico-arytenoids made to approach the median line. There is left a
triangular opening at the base of the cartilages, through which the air
escapes in the act of speaking. This, the {85} cartilaginous portion of
the glottis, remains patent even though the anterior three-fourths of
the space be closed. The result is generally, but not always, a loss of
speech. The air whistles through this opening, but phonation is
difficult or absent. The causes are to be sought in the derangements
resulting in the loss of power of the other muscles. Upon examination
with the laryngoscope the triangular opening is readily seen. The
ligamentous portion of the glottis is seen to close in the effort to
speak, while the cartilaginous portion is widely open. There is no
other morbid condition necessarily present. The trouble is frequently
associated with paralysis of the adductors of the two sides--that is,
the lateral crico-arytenoids. In these cases there is complete
separation of the cords throughout the whole length.
The DIAGNOSIS is easy except in instances where there is ankylosis of
the articulation of the cartilages. Even in these cases a careful study
of the parts, as revealed by the mirror, will enable the observer in
most instances to recognize evidence of structural disease on the walls
of the larynx. There will also be a history of some antecedent
affection, such as syphilis or tuberculosis, or possibly arthritis. The
course and termination of this form of paralysis depend largely upon
the etiology in any given case.
Paralysis of the Tensors of the Vocal Cords.
It will be remembered that these are in two groups, the internal and
external.
The internal are the thyro-arytenoids. While their function is in part
still a matter of discussion, it is very generally conceded that they
have to do with the form and tension of the cords. Their paralysis
produces a very marked derangement of the functions of the larynx as
the organ of speech. They act ordinarily along with the crico-thyroids,
but from the fact of their separate innervation it would seem very
probable that they should be the seat of special functional
derangements. In fact, it is true that their paralysis in a limited
number of cases is found to be quite independent of any disturbances of
the external tensors.
ETIOLOGY.--In addition to the general causes of laryngeal paralysis,
the use of the voice in an unnatural or too high a key or the too
long-continued use of the organ may result in a temporary or even
permanent impairment of the power of these muscles. Their exposure to
the causes of inflammation, lying as they do so near the surface of the
mucous membranes, subjects them to the morbid influences of the
catarrhal troubles to which the glottis is liable. They are probably
more frequently affected than the literature of the subject would lead
us to suppose, as in many cases the disease is temporary.
SYMPTOMS.--These consist mainly in the alteration of the voice. It is
hoarse, the register is lower, the quality is uneven. Occasionally a
note is, if not lost, uttered with difficulty; some letters, such as
the aspirates, requiring the careful adjustment of the glottis, are
articulated with great uncertainty. There is what has been called a
rattling of the voice. It is quite impossible to sing or to speak long
in a high key; even prolonged ordinary conversation gives rise to
fatigue, for the reason that there is so great a waste of air in the
effort. The pressure upon the under surface of the cords in their
relaxed condition forces its way upward and through the glottis without
throwing them into normal vibration.
DIAGNOSIS.--The laryngeal mirror reveals the glottis only partly
closed. There is an oblong opening extending from the thyroids to the
base of the arytenoid cartilages. The vocal processes even are not
brought to the median line, but are so far apart as to leave a
noticeable slit between them. It seems from this fact that these
muscles are therefore the aids of the lateral {86} crico-arytenoids in
the rotation of the cartilages on their bases. In the effort at
phonation the cords are seen to move with difficulty. The disease may
be unilateral or bilateral.
This form of paralysis in course and termination does not in any
essential respect differ from other paralyses of the larynx. The
duration is therefore very uncertain, and will depend largely upon the
cause of the affection.
Paralysis of the External Tensors of the Cords.
This is a rare disease, but is present in complete paralysis of the
superior laryngeal nerve. It is then associated with anæsthesia of the
superior portion of the glottis, as well as paresis of the depressors
of the epiglottis, and generally of the constrictors of the vestibule
of the larynx.
ETIOLOGY.--It may be the result of injury to the external branch of the
superior laryngeal in its distribution to the muscles. It may be caused
by diphtheria. It is possible that the motor fibres of the superior
laryngeal nerve may be alone involved, while the sensitive portion is
still normal. Cases of partial paralysis are recorded by Von Ziemssen,
Gerhardt, and others.
The SYMPTOMS are such as we should expect in diminished tension of the
vocal bands: lowering of the pitch of the voice, with inability to
reach the higher notes. There ought to be, therefore, hoarseness. Acute
paralysis of this muscle has been known to produce aphonia (Ramon).
DIAGNOSIS.--It is said that this form of paralysis gives rise to a
well-recognized condition which may be seen in the laryngeal mirror.
The cords are described as wavy, irregular in their relation to each
other, like the position of two pieces of ribbon, which, having an
attachment at their extremities near to each other, are allowed to fall
into folds. This condition, if ever present, is, I am convinced, very
rare. It is probable that the descriptions have been given to
correspond with what ought to be seen, rather than what is actually
seen, in the mirror. There is said to be a slight depression of the
vocal processes in the act of inspiration, and a corresponding
elevation of them in the act of expiration and phonation. The
diminished tension should produce this change in position. The disease
may also be recognized by placing the finger upon the edge of the
crico-thyroid muscle during the effort to speak. The muscle acts so
strongly in the healthy condition that it may be easily felt; in
paralysis this contraction is wanting.
The course and duration of the disease must depend upon the cause and
complications. When the muscles suffer in common with the sensory
apparatus supplied by the superior laryngeal nerve, as in the case of
diphtheria, there is reason to expect that it will disappear with the
other morbid phenomena.
Paralysis of the Posterior Crico-Arytenoids.
The functions of these muscles render any loss of their power as
glottis-openers a matter of importance. It will be remembered that they
are so situated that they not only rotate the arytenoids, turning the
vocal processes away from each other, but they also serve to fix the
cartilages, giving them a firm support as points of attachment for the
vocal cords. The outer fibres tend also to draw the body of the
arytenoids away from each other, as well as to fix them in a
postero-lateral position. They are, more than any other of the muscles
of the larynx, organs of respiration. They are also in constant action:
with each inspiration they contract, and during expiration they {87}
fall into rest. In this respect they resemble the other muscles of
respiration and the central organ of the circulation. In some respects
they also resemble the muscles of the heart in the degenerative changes
to which they are subject. Their antagonists are the lateral
crico-arytenoids. When both sets of muscles are paralyzed, the glottis
is in what is known as the cadaveric condition; that is, the vocal
cords are neither widely separated nor parallel to each other. There is
an opening of a triangular shape as in the act of easy inspiration, not
sufficiently approximated to admit of speech, but sufficiently open to
admit of free inspiration. With this understanding of the physiology of
the parts, we can readily appreciate the results of the loss of power
of these muscles. As stated by Bosworth, the especial danger is in the
integrity of the adductors, tending for the want of antagonism to keep
the glottis closed. Of all the muscles of the larynx, these are
therefore the most important so far as life is concerned.
The disease is progressive (Lefferts, Semon, Bosworth).
The first symptom which attracts attention is generally inspiratory
dyspnoea while taking active exercise. The difficulty continues to
increase till there is constant difficulty in the act of inspiration,
usually with spasm. The dyspnoea is more marked during sleep than when
awake. Death may occur at this period of the disease before the gravity
of the trouble has been recognized. As a rule, tracheotomy will be
required to prolong life, after which the dangers to the patient are
passed.
The ETIOLOGY of this form of paralysis presents some peculiar problems.
In all paralyses of the individual muscles we are obliged to invoke
nerve-changes in special nerve-cells in the centres from which the
individual nerves have their origin--changes along the course of the
nerves; or, on the other hand, some myopathic change in the muscles
themselves. In the muscles now under consideration we have a special
function--namely, respiration--involved. The disorder is usually
limited to these muscles alone. If it becomes general, it commences
here. The phonators not being involved, it is probable that in a part
of the cases reported the essential cause of the paralysis must be
ascribed to disease in a centre in the brain, or at least along the
course of the nerve near its origin. Other cases are evidently due to
pressure on the pneumogastrics or recurrents. This view has been
proposed by Bosworth. Von Ziemssen and others have thought that
syphilis enters very largely into the pathology of this group of cases.
There has been noted, as confirmatory of this proposition, that other
symptoms of central disease have been in a few instances observed.
Diseases affecting the recurrents have been known to affect these
muscles alone: Ingals reports cases. On the other hand, it is quite
certain that in a large majority of the cases recorded there has been
no satisfactory cause assigned. In nearly all of the post-mortems there
has been found a degeneration of the muscles. This is as we should
expect to find it where the structures have been for a considerable
time in a state of inaction. The histological change may possibly be in
any case only the result of the paralysis, and not the cause of it. In
a few instances there has been discovered a degeneration of the
nerve-trunks by which the parts are supplied. As to the causes by which
the muscles may become affected, we can imagine that the exposed
position suggested by Mackenzie renders them peculiarly liable to
mechanical injuries from hard substances forced down the oesophagus.
They are subjected to changes of temperature produced by hot and cold
drinks and food. Their relation to the seat of local inflammation of a
specific as well as of a non-specific character renders them liable to
become involved in morbid processes. The fact that the disease
occasionally occurs after diphtheria, as I have in two instances
demonstrated, gives additional weight to this hypothesis. The fact
probably is that there are several varieties of the affection. The want
of more accurate information as to the {88} previous history, as well
as to the immediate antecedents of the attack, renders it impossible as
yet to differentiate the cases due to one or other of these causes. For
the present, then, we may conclude that paralysis of these muscles may
depend upon either disease of the centres, disease along the track of
the nerves, pneumogastric or recurrent, or to disease of the peripheral
branches or fibrils, or to disease of the muscles themselves.
SYMPTOMS.--These are at first so slight that the trouble is usually not
recognized till it has reached such a stage that the act of inspiration
is either attended with fatigue or there is stridor which annoys the
patient or alarms his friends. Soon afterward there begins to be a
dyspnoea, a difficulty in breathing, especially during any active
exertion and during sleep. The voice in the mean time remains normal.
Expiration is free. The general health is usually undisturbed. There
may be a catarrhal affection of the mucous surfaces, but if so it is
quite accidental. Spasm supervenes. There is at times great difficulty
of breathing, and, finally, the effort becomes so great that the
patient becomes alarmed. Upon examination with the laryngoscope the
vocal cords are seen in close proximity to each other even during the
inspiratory effort. In fact, they are, by the pressure of the air upon
their upper surfaces, brought closer together during inspiration than
during expiration. They seem to act as valves which are closed by the
weight of the atmosphere upon their wide, flat upper surfaces, pressing
them against each other. Hence the inspiratory stridor and dyspnoea.
The act of expiration is a passive one in health, and in this condition
the air is easily forced out by pressing the cords away. The order of
the movements of the cords is therefore changed--in the normal
condition wide in inspiration, narrow in expiration; in this disease
narrow in inspiration, and while not wide, at least wider, in
expiration than in inspiration. In other respects the parts are normal.
There is nothing to suggest the trouble except the closure of the
glottis during inspiration.
The course and duration of the disease are in a large majority of cases
chronic. Once established, it tends to persist. The cases of
diphtheritic origin should be excepted from this statement. In those
forms in which the trouble is entirely in the muscles of the part life
may, so far as we know, be continued indefinitely. Where the trouble is
central it is probable that the cause has a tendency to involve other
parts of the brain, and in this way to lead to other, and possibly
dangerous, complications. Of this, however, we know but little. The
paralysis is not directly the cause of death, except as it closes the
glottis. The dangers are therefore mechanical. When the patient has
once been placed in a condition of safety by the operation of
tracheotomy the local paralysis no longer endangers life.
Mackenzie, Von Ziemssen, Cohen, and in fact almost all writers upon the
diseases of the larynx cite and publish cases by the way of
illustration of the symptoms, course, and termination of this class of
troubles. They are now so numerous that it would seem to be hardly
necessary to do more than to give the conclusions which the recorded
instances suggest. Fortunately, this form of laryngeal disease is rare,
and when present it is easily recognized. The treatment is clearly
indicated. In all cases in which the inspiratory difficulty is marked
tracheotomy should be performed, even though suffocation does not seem
to be imminent. The treatment for the radical cure of the disease must
be in the main the same as that required in other forms of laryngeal
paralysis.
TREATMENT OF PARALYSIS OF THE LARYNX.--The grouping of these disorders
for the purpose of description has, for the reasons already given, been
based largely upon symptoms. For the purpose of treatment we may
properly divide them with reference to their causes. With these in
view, we have, first, those cases in which the cause of the affection
is within the {89} cranium--central disease; second, those in which the
loss of power is the result of disease or pressure along the course of
the nerves outside the cranium and before reaching the larynx; third,
those in which there is disease of the structure of the larynx itself,
nerves or muscles; fourth, those in which the cause is to be found in
some distant part--reflex paralysis; fifth, those of toxic origin. This
last includes paralysis after typhoid fever, diphtheria, etc., as well
as those produced by lead, arsenic, mercury, and possibly copper and
other toxic agents.