W. R. (William Richard) Gowers.

A manual of diseases of the nervous system (Volume v.1) online

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paralysis of the plantar muscle, there is loss of the inward rotation of
the flexed leg, if the disease is so high as to involve the branch to the
popliteus, and there is also loss of the power of extending the ankle-
joint. Talipes calcaneus results (Fig. 28, p. 43). The sensory loss
is on the outer lower part of the back of the leg, and on the sole, but
varies much.

The 'plantar nerves rarely suffer alone. A lesion of the internal nerve
causes anaesthesia on the inner part of the sole, and plantar surface of
the three inner toes and half the fourth, together with paralysis of the
short flexor of the toes, the plantar muscles of the great toe (except
the adductor), and of the two inner lumbricales.


Disease of the external nerve produces anaesthesia of the skin on the
outer half of the sole, the little toe aud half the fourth, paralysis of
the flexor accessorius, the muscles of the little toe, all the interossei,
the two outer lumbricales, and the adductor of the great toe. The
effect of this palsy (see p. 45) is serious, since the toes cannot take
their proper share in propelling the body forward in walking, and they
gradually become flexed at the last two joints and extended at
the others, from the contracture of the opponents of the inter-
ossei, — aposition . of the toes that causes serious inconvenience in

Diagnosis. — The diagnosis of diseases of the nerves of the leg is
determined by the same general principles as those that have been
mentioned as applicable to the nerves in general, and to the nerves
of the arm in particular. The limitation of the symptoms to the
functional areas of individual nerve-trunks, the evidence afforded by
nutrition, irritability, and reflex action that the muscles are separated
from the spinal cord, the implication of the sensory functions, and
often the tenderness of the affected nerves, indicate, in most cases,
the seat of the disease. To these signs, are often added other indica-
tions of a local cause, corresponding, in its position, with the nerve
to which the symptoms point.

The relation of nerve-trunks to nerve-roots, although by no means
simple, is certainly less complex in the case of the nerves of the leg
than in those of the arm. This is especially the case in the lumbar
plexus, and it leads to an occasional difficulty in diagnosis. Pressure
on the spinal cord, for instance, at the level of the origin of the fourth
lumbar roots, may cause symptoms identical with those of a partial
lesion of the anterior crural nerve, For instance, I have known para-
lysis of the extensors of the knee, loss of the knee-jerk, with anaesthesia
in the front of the thigh, to be the result of a gumma at the side of the
cord at this level. But other evidence of a spinal lesion is rarely absent
under such circumstances, and, in this patient a foot-clonus, due to the
pressure on the pyramidal fibres, left no doubt as to the situation of the
disease. Another difficulty arises from the long course of the nerve-roots
in the cauda equina, disease of which may simulate that of the nerves of
the leg. But the symptoms are commonly bilateral in consequence of
the proximity of the nerve-roots of the two sides. In all cases in which
symptoms are bilateral (unless there is evidence of a disease known
to cause symmetrical lesions, such as multiple neuritis), the suggestion
is that the disease is situated where the motor or sensory paths of
each side are so near that they can be affected by a single lesion, i. e.
that the disease is within the spinal canal. But here, as in other
cases, we cannot reverse our diagnostic rules. Disease of the spinal
cord does not always cause bilateral symptoms. A limited lesion of
one anterior cornu may be so placed as to paralyse the muscles supplied
by a single nerve, and a doubt may be felt as to the central or peri-
pheral origin of such palsy. The muscles supplied by the anterior


crural nerve, and the muscles in the front of the lower leg supplied
by the external popliteal, are those of which the central palsy most
often leads to doubt. The mode of onset, the presence or absence
of sensory symptoms, the rarity of acute spinal palsy except in child-
hood, and of nerve-lesions except in adult life, the wider initial pre-
valence of the palsy in acute, and its later extension in chronic,
cornual disease, — these suffice as a rule to remove any doubt.

It is important to remember that the pressure of a growth may
cause either a chronic or an acute affection of the nerves. The chronic
symptoms result from compression ; the acute from a neuritis set up
by the pressure and irritation.

Treatment. — The treatment of disease of the nerves of the leg
does not differ from that of disease of the nerves of the arm. More
care, perhaps, is needed to avoid increasing present mischief, or
inviting a relapse, by exposure to cold or by fatiguing exertion. More
care is also needed to obviate the tendency to secondary contractures in
the case of palsies of long duration, and in those attended by pain, in
which the patient seeks ease in postures to which the muscles only too
readily adapt themselves. The contraction of the hamstrings, from con-
stant flexion of the knees, occurs very readily and is most troublesome ;
that of the calf muscles, which occurs when the flexors of the ankle are
paralysed, also constitutes a serious obstacle to walking after recovery.
A little timely care, by attention to posture, will often save a vast
amount of later trouble. That of the calf muscles, however, which
is due to the extension produced by the weight of the foot, as the
patient lies, cannot always be entirely prevented, but may be lessened
by a board or large sand-bag against which the feet can rest.


Besides the forms of inflammation of the nerves of the arm alreadv
described, a primary inflammation of the brachial plexus occurs in aform
as well defined as sciatica, and equally meriting a separate description.
This, however, need only include its special features ; those that are
common to other forms of neuritis have been already described. It
is so closely analogous to sciatica that it may be called " sciatica of the
arm." It is essentially a perineuritis, — a primary inflammation of
the sheaths of the branches that enter and form the brachial plexus.

Cases occur, however, in which the symptoms correspond in general
character to the rest, but in which their distribution suggests that the.
nerve-roots rather than the plexus are the seat of the inflammation,
and pain about the spine sujrports the opinion. This form may be
called Radicular Neuritis. Although its existence has not been

vol. i. 7


established by pathological evidence, the symptoms mentioned admit
of no other explanation. A knowledge of their significance is of great
practical importance on account of the closeness with which they may
simulate those of organic disease of the bones of the spine, or a growth
in the spinal membranes.

Causes. — The influence of gout in causing local neuritis is very
conspicuous in the brachial form, with the special characteristic that
this occurs chiefly late in life, very often from the inherited disease, and
with greater frequency in females than any other form of neuritis ;
their liability is at least equal to, if not greater than, that of men.
Five-sixths of the cases occur after fifty, and it may be met with up
to extreme old age. In men there have usually been the ordinary mani-
festations of gout, but in women the tendency is often only indicated
by the family history, and by previous muscular rheumatism, especially
lumbago and sciatica, — which have seldom been absent in either sex.
In one case the onset of the brachial neuritis occurred immediately
after an attack of sciatica.

Symptoms. — Pain, the great symptom of the inflammation of all
mixed and sensory nerves, is greater in this than in most forms of
neuritis. It is usually the first symptom, and lasts long after the in-
flammation is over ; its severity, coupled with the age of most sufferers,
renders the malady one of a peculiarly trying character. The first
pain is often referred to a distance from the seat of the inflamma-
tion, perhaps because this begins at the plexus, where, at divisions,
it is facilitated by motion, and the conducting fibres are readily
reached and early irritated. Frequent seats for the first pain are
the region of the scapula (sometimes beneath the bone) and the
wrist or back of the forearm, with or without the hand. In other
cases, however, the first pain is at the plexus itself, above the clavicle
or in the axilla, and these are the places in which it is commonly
most intense throughout the attack. As the pain increases it extends
along the course of the nerves of the arm, which the patient will often
accurately indicate with his finger when tracing the lines of pain.

The pain is sometimes sudden in onset and severe from the beginning;
more often it is at first occasional, or felt on certain movements, but,
as it increases, it becomes more continuous, with variations that soon
rise to paroxysmal degree. Ultimately there is always more or less
dull wearying pain in the whole arm, but especially in the region of
the plexus, varied by attacks of great severity. In these the pain
is acute and lancinating, or stabbing, or burning ; it usually takes the
course of the nerves, diffusing itself from them, and often passing
to the side of the chest, and to the neck, — seldom to the head. The
pain often varies in character according to intensity ; at the height of
the paroxysm it may be sharp and stabbing, or such darting pains may
be superadded to a more diffused burning pain, which lasts longer
than the acute pain, and may be followed, as the paroxysm subsides,
by general tingling of the skin of the whole limb. The paroxysms are


induced "by movement or occur spontaneously. In slighter cases the
pain is paroxysmal only, and then the relation to movement is a very
conspicuous feature. Although it is seldom confined to movement, this
never fails to induce severe pain, and the patient avoids the slightest
use of the limh. Elevation of the arm especially causes distress.

With the pain there is usually undue sensitiveness of the skin,
which may be much increased during and after the paroxysms. Loss
of sensation is rare, and is met with only in cases that are not only
severe but prolonged. The two may concur, as " anaesthesia dolorosa."

The muscles usually present the flab^iness and slight wasting
common in neuritis, but the damage to the motor fibres is seldom
sufficient to cause considerable atrophy. Sometimes, however, there
is enough damage to cause wasting of some group of muscles, with the
reaction of degeneration. This is most frequent in the radicular form,
in which the damage is to the upper part of the plexus and nerve-
roots. There may then be anaesthesia of the skin over the affected
muscles. It. is difficult to ascertain the existence or the amount of
motor weakness ; effort induces pain so readily that the patient can
seldom be induced to make an attempt to exert force. Power is often
said to be almost lost, when it is probably greater than is believed.
Besides the muscles, the subcutaneous tissue of the limb may also
waste, and the skin may become thin and shining, and present the
aspect already described. Subcutaneous cedema is also common.
Arthritic changes in the joints of the fingers are almost constant in
the cases that occur in later life ; the adhesions may be permanent.

Diagnosis. — Few maladies, as a fact of experience, give rise to greater
diagnostic difficulty. This is due to several causes : the affection is
rare; its symptoms are sometimes equivocal ; the subjects are usually
in the degenerative period of life, when many obscure diseases attended
with pain in the arm occur to the mind of the physician ; and lastly,
the distinction between neuralgia and neuritis is often difficult, although
less so than is supposed. The last is indeed the most frequent
source of error. The most severe and characteristic cases of brachial
neuritis are frequently mistaken for pure neuralgia, on account of the
paroxysmal character of the more severe pain, and "because the cha-
racters of neuritis are unfamiliar. The points to determine the
diagnosis are those described in the sections on neuritis and neuralgia ;
— the degree of persistent tenderness of the nerves and the influence
of movement, together with the history of the attack, the locality of the
pains, and especially any evidence of damage to the fibres. A history
of neuralgia in the person or the family is of slight weight only ; the
tendencies to true neuralgia and to neuritis are often combined, and
each is a frequent result of gout. A far greater difficulty is presented
by the cases in which the inflammation remains slight and is confined
to the plexus, affecting branches where the conducting fibres can be
so irritated as to cause distant pain, which then becomes the leading
symptom. This is often paroxysmal, and, when on the left side, may


radiate to the chest and be associated with disturbed action of the
heart. Angina pectoris is often thought of in such cases ; and here
a°"ain the degenerative age may increase the difficulty by leading to
the presence of some coincident disease of the heart, or by making true
angina not unlikely. The distinction afforded by the nerve-tenderness
is then of great importance, because the disproportionate amount of
tenderness (compared with the amount of pain) is' more emphatic in
slight than in severe cases. Persistent tenderness with only parox-
vstnal pain should always suggest neuritis. When the position of the
pain is carefully examined, its relation to the plexus and branches is
often clear. It is important to remember that all nerve-pains in the
brachial region on the left side have a tendency to resemble angiual
pain in distribution, and to be associated with cardiac distress.
Probably there is some peculiar tendency for pains in this part to
disturb the action of the heart; a common physiological relation may
underlie both the nerve-pains of cardiac angina and the cardiac sym-
ptoms of nerve-pains. Hence this secondary disturbance does not
neutralise the significance of the special signs of neuritis. In some
cases of the slighter class, the pains suggest the idea of an aneurism ;
in many cases of brachial neuritis this diagnosis has been made, and
the patient has had to endure months of mental distress, for which
no real cause was in existence. Such a suspicion, in the absence of
special signs, such as pressure-symptoms, should only be entertained
if the pains are persistently and increasingly severe, and unaccom-
panied by any considerable amount of tenderness. In all these cases,
moreover, the presence of the gouty diathesis may be allowed weight
in the diagnosis.

The muscular wasting, slight in degree, added to the arthritic
changes, gives rise to a condition which may be mistaken for a primary
joint affection with secondary " arthritic atrophy " of the muscles. It
is only in the chronic stage that this error is possible. A careful
attention to the history of the case will show its real nature, but with-
out this attention the mistake is easy, and it is often made.

Prognosis. — Except in its most trifling degree, brachial neuritis is
a tedious malady ; the duration of every severe case is to be measured
by months, and often more than a year elapses before the patient is free
from pain. Post-neuritic pain is always more prolonged in the old than
in the young, and the age of the subjects, together with the amount of
damage to the nerves, causes suffering to last longer than in almost any
other form. To these causes also must be added the degree of sen-
sitiveness of the affected nerves, exceeded only by that of the fifth
nerve, and also the mobility of the parts in which the plexus lies ; this
involves a continued cause of irritation, brought into play as soon as the
diminution in the severer pain permits the patient to employ the long
useless arm. Relapses, moreover, are not uncommon. "Recurrence
may take place after moderate attacks, but seldom occurs after those
of extreme severity.


Becovery from the consequences of the inflammation is not always
complete. The limb often remains smaller and feebler, with a liability
to tingling and to cramp, and also to neuralgic pains under the influence
of changes in the weather, &c. But the most serious consequences
are the alterations in the joints. These are very frequent : the fixa-
tion occasioned by the pain permits, and the tendency to perverted
nutrition produces, adhesion between the articular surfaces, in con-
sequence of which the movement becomes permanently restrained.
It is probable, moreover, that the constitutional state which underlies
the primary malady often increases the degree of these joint-alterations.
The shoulder, wrist, and fingers are the joints that are most frequently
thus rendered stiff. The interference with the movement of the fingers
is especially troublesome; the joints become painful in consequence of
the unavoidable strain on the tissues when an attempt at use is made.

Treatment. — The treatment that has been described, as needed in
neuritis generally, is suitable also for this form, and its details need
not here be repeated. Abstinence from movement is of great import-
ance ; the occurrence of stiffness of the joints in consequence of the
immobility of the limb must be risked. It is doubtful, indeed, whether
the tendency to this is much increased thereby, for the effect of pain, in
preventing sufficient movement to maintain the normal state of the
joints, is not materially increased by rest otherwise enforced ; while
the difference between a little movement and none, during the acute
stage of the affection, is enough to make a considerable difference in
the effect on the inflammation of the nerves. The influence of cocaine,
injected under the skin, is very beneficial, but it is needed frequently
in severe cases, and two injections (each -^ — -|- gr.) may be given
daily during the height of the disease. It is important that the nerves
should not be irritated by massage in the state of active inflammation ;
indeed, no therapeutic measure which occasions pain can do as much
good as harm. After the tenderness has subsided, gentle rubbing,
such as is agreeable, may be employed with advantage. Electricity is
only needed for muscles that present the reaction of degeneration, or
to aid in removing after-pains.


As the word sciatica is commonly used, it is a general designation
for all affections of which the 'chief symptom is pain in the region of
the sciatic nerve. It is thus often applied to the pain which results
from pressure on the nerve in the pelvis, as by a tumour. In a stricter
use of the word, however, it is applied to painful affections of the nerve
not due to any cause outside it. The two varieties may be distinguished


as secondary and primary sciatica. Primary sciatica is commonly
regarded as a neuralgia. This view is in the main erroneous ; the
vast majority of cases of sciatica are really cases of neuritis of the
sciatic nerve. The reasons for this opinion are given in the section on
the pathology of the disease.

Causes. — Sciatica is far more frequent in males than in females ;
the proportion has been very variously estimated. It is difficult to
obtain statistics on the malady that are free from sources of fallacy,
since comparatively few cases enter general hospitals. The incidence
of severe sciatica seems to be fairly presented by the 137 cases that
were treated in the Devonshire Hospital, Buxton, during the year 1883,
and there is no reason to suppose that slight cases differ, in this
respect, from those that are severe. The percentage of males is 82 ;
of females, 18 ; giving a ratio of 4 to 1, which is probably very near
the truth — a remarkable contrast to the analogous affection of the
arm. The disease is unknown in childhood, and rare in the second
decade of life. It is most frequent between forty and fifty, next
between fifty and sixty, and next between thirty and forty. The per-
centage distribution of the 137 cases at Buxton is as follows : — Ten
to twenty, 3 per cent. ; twenty to thirty, 9 per cent. ; thirty to forty,
19 per cent. ; forty to fifty, 29 per cent. ; fifty to sixty, 23 per cent. ;
sixty to seventy, 13 per cent. ; over seventy, 1 per cent. The influence
of age is nearly the same in each sex.

Two constitutional conditions are potent factors in the production of
sciatica— gout, and that form of rheumatism which affects chiefly the
fibrous tissues of the muscles. These two constitutional states cannot
be entirely separated, but many of the sufferers are of opposite tvpes :
some are stout, plethoric, distinctly gouty; others pale, weakly, and
rheumatic. Many of the latter owe their rheumatism to inherited
gout ; rheumatic fever is certainly one of the effects of this family
tendency. Sciatica is most common among those who are gouty
but do not suffer from articular gout, and such individuals often have
many attacks. Gouty inheritance is generally to be traced in those
who suffer early from the disease. Syphilis has been supposed in
some cases to be the cause of a sciatic neuritis, but the cases are so rare
as to make strong and clear evidence desirable.

An exciting cause is to be traced in many of the cases. Exposure
to cold is the most common. It is usually local exposure, as by wet
boots, standing in water, &c. ; sometimes, however, a general chill
of the body determines an attack. The expos are to cold may be
even more direct, as by sitting on wet grass. I believe that draughty
water-closet seats are answerable for some cases. The neuritis often
arises by the extension of an adjacent rheumatic affection of the
fibrous tissue, especially of that form of lumbago which involves
the fibrous attachments of the muscles at the back of the sacrum.
This passes down, extending along the fascia3, to the nerve-sheath in
the neighbourhood of the sciatic notch. (The fact is of much interest,


because it shows that this form of rheumatism must be regarded as
inflammatory since it can spread as inflammation.) A few days
after the pain reaches the nerve-sheath there may be all the signs
of intense inflammation. Mechanical causes also sometimes excite
the disease, and still more often co-operate with other influences.
The pressure of the edge of the chair, in those who sit much, is the
most frequent mechanical cause. Muscular over- exertion has been
thought occasionally to excite the disease. If the nerve is already
tender, a strong contraction of the muscles at the back of the thigh,
especially when the knee is flexed, and the muscles can freely shorten
and widen, may produce acute pain in the nerve, evidently by its
compression. It is conceivable, therefore, that this cause may be
effective in a predisposed person. Various morbid processes within the
pelvis may cause symptoms of sciatica, usually by acting on the sacral
plexus. Thus rectal and other tumours, pelvic inflammation, and
injury during labour are occasional causes. A loaded rectum hasbeeu
thought to be capable of producing sciatica. Mechanical congestion of
the plexus of veins which lies over the sacral plexus of nerves is usually
regarded as an occasional cause, but this is somewhat hypothetical,
and its efficiency can scarcely be demonstrated. Lastly, the sciatic nerve
may be secondarily involved in mischief that is outside the pelvis. The
most frequent cause of this is disease of the bone, and especially disease
of the hip-joint. In all these forms of secondary sciatica the symptoms
are due partly to pressure on the nerve, partly to inflammation
excited in it by the pressure, or extending to it from the adjacent

Pathological Anatomy. — Sciatica being a disease that does not
itself cause death, observations of the morbid changes are few. In
most cases that have been examined, distinct evidence of neuritis has
been found, chiefly involving the nerve-sheath, but extending in some
cases to the interstitial tissue. The changes are those that have been
already described in the account of neuritis (p. 54). In recent cases
there is swelling and redness of the sheath, sometimes there are small
haemorrhages, and, in severe cases, similar but slighter alterations in

Online LibraryW. R. (William Richard) GowersA manual of diseases of the nervous system (Volume v.1) → online text (page 13 of 79)