side and diplopia is present when the vision is directed downward.
The sixth nerve, the abducens, may be paralyzed as a result of lesions
similar to those affecting the third and fourth nerves. It produces internal
strabismus since the only muscle supplied by it is the external rectus. The
eyeball cannot be turned so as to look outward. Double vision may be present
when the patient looks toward the paralyzed side. In affections of the
nucleus of origin of this nerve, conjugate deviation of both eyes away from the
side of the lesion, is observed due to the fact that the nucleus of the third
nerve is connected with that of the sixth, consequently in lesions of the latter
the internal rectus is paralyzed in associated movements, although the nucleus
of the third nerve which supplies this muscle is not affected; there is no dis-
turbance of the power of convergence.
General paralysis of all the motor nerves of the eye or ophthalmoplegia
may be caused by disease of the nuclei of origin of the third, fourth, and fifth
nerves, by tumors and the pressure of inflammatory exudates, and may occur
in general paresis, locomotor ataxia and progressive muscular atrophy. It
occurs in two forms, ophthalmoplegia externa and ophthalmoplegia interna.
The two types may co-exist â€” total ophthalmoplegia. In the external type
the eyeball is immobile, ptosis is present and there may be slight exophthal-
mos; with it there may be optic nerve atrophy and involvement of other
DISEASES OF THE FIFTH PAIR: THE TRIGEMINAL NERVES. 78 1
In the internal type power of accommodation and pupillary reaction are
lost. Ophthalmoplegia is usually a chronic condition but rarely an acute
form is observed, the onset of which may be rapid; accompanying this type
are cerebral disturbance and haemorrhagic degeneration of the nuclei of
origin of the motor nerves of the eyeball.
Treatment of the ocular palsies. This, to a great extent, depends upon
the cause. In acute cases the pain may be relieved by hot compresses, mild
counterirritation and the application of leeches to the temples. Syphilitic
cases and those occurring in the course of locomotor ataxia should receive
mercury and potassium iodide in large doses. Strychnine, hypodermatically
in considerable doses, -g-^ to -^V of a grain (0.002-0.003), arsenic and iron
are also useful; the three may be given in combination. In the chronic type
the use of electricity is recommended. If galvanism is employed the anode
is applied to the forehead and the cathode is moved along the margin of the
orbit over the affected muscles; if the faradic current is used the cathode
is not moved. For the ptosis the current is applied over the third nerve.
Double vision may be relieved by the use of prisms, or if it is impossible
of correction, both it and the dizziness may be obviated by wearing an opaque
glass over the affected eye.
DISEASES OF THE FIFTH PAIR: THE TRIGEMINAL NERVES.
Lesions of the fifth nerve result from disease of the pons, especially haemor-
rhage or sclerosis; injiury or disease at the base of the cranium, such as bone
caries, meningitis, syphilitic or other new growths; pressure upon the branches
of the nerve from tumors or aneiu"ysms in the cavernous sinus or from lesions
in the spheno-maxillary fossa. Primary inflammation of the nerve is rare.
Sensory symptoms may be caused by hysteria and disturbances of taste
by the influence of disturbances of the facial nerve upon the chorda tympani.
Motor disturbances. These consist of paralysis and spasm. The former
involves the temporal, masseter and pterygoid muscles and is characterized
by difl&culty in mastication; if both sides are involved this act is impossible
and the lower jaw hangs down. If only one side is affected the jaw is displaced
toward the affected side when open.
Spasm occiurs with muscular cramp, in tetanus (lockjaw or trismus), in
tetany, and meningitis. It is seen also in hysteria and as a restdt of diseases
of the mouth, jaw or teeth. The jaws are tightly shut and the contraction
of the muscles of chewing may be painful. Clonic spasm (chattering teeth)
may occvir in chorea, hysteria and without assignable cause.
Disturbances 0} taste resulting from lesions of the fifth nerve consist in the
partial or complete loss of this sense over the anterior two-thirds of the tongue
782 DISEASES OF THE NERVOUS SYSTEM.
as stated by some, although it would seem from the fact that many trigeminal
neurectomies do not result in gustatory disturbance that the nerve fibres from
this part of the tongue may reach the brain by more than one route.
Sensory disorders are characterized by loss of sensation of half the face,
conjunctiva, cornea, mucous membrane of the lips, tongue, hard palate and
nose of the same side. Smell is rendered less acute as a result of drying of
the nasal mucous membrane; taste may be disturbed. Painful tingling may
precede the anaesthesia. Trophic disturbances occur such as diminution of
the saliva, the lachrymal, buccal and nasal secretions and the teeth may become
loose. Herpes with pain may develop over the course of the nerve and there
may be facial oedema. The diagnosis is simple. Taste may be tested by
touching the tongue on either side with a weak acid solution and comparing
the effect, motility by directing the patient to bite a piece of soft wood, and
sensation by the usual methods.
Treatment should be directed to the removal of the causative factor. Syphil-
itic cases should receive appropriate treatment. The teeth should be put in
proper order, nasal and aural examinations should be made and any existing
abnormality corrected. Anaesthetic parts shoiild be protected against injury
and irritation. The pain may be relieved by the means described under the
section on the treatment of neuritis (p. 769) and the local applications there
mentioned are also useful. Morphine should be employed as a last resort
The use of the faradic current and of massage is indicated in order to restore
the muscular tone, and attention should be given to the general health of the
DISEASES OF THE SEVENTH PAIR: THE FACIAL NERVES.
Disease of the facial nerve may result in paralysis or spasm.
Paralysis (Bell's palsy, monoplegia facialis or mimetic facial paralysis)
may be caused by lesions in the cortex, in the brain between the cortex and
the nucleus of origin of the nerve, in this nucleus and in the nerve itself. The
cortial lesions occur with hemiplegia due to cerebral haemorrhage, inflam-
mations and tumors; those of the nucleus result from like causes and from
the toxins of infectious diseases, especially diphtheria, and lesions of the nerve
itself may be caused by exposure, extension of middle ear or temporal bone
disease, new growths, injury at the base of the brain, meningitis or syphilitic
infiltration in the same situation. The nerve may be affected in lesions of
the medulla oblongata, and as a result of traumatism during birth.
Symptoms. These differ with the site of the lesion causing the paralysis.
The onset of the condition is usually sudden but at times prodromal symp-
toms such as disorders of taste, facial and aural pain and tinnitus, are noticed.
DISEASES OF THE SEVENTH PAIR: THE FACIAL NERVES. 783
As a rule the paralysis is one-sided, rarely is it bilateral. The face is drawn
toward the sound side, except after contracture, in cases of long standing.
The affected side of the face is immobile and smooth, the forehead loses its
wrinkles, the power of facial expression is lost, the eye remains open even
during sleep, the corner of the mouth drops and there is dribbling of saliva,
whistling is impossible and the labials are pronounced with difl&culty; the
tongue is not deviated and during mastication the food collects in the paralyzed
cheek. The corneal reflexes are lost, the eye waters and conjunctivitis is
frequently observed. Winking is impossible if the paralysis is complete.
Drinking is difl&cult on account of the inability of the patient to approximate
his lips to the glass.
In lesions of the nerve between its union with the chorda tympani and the
geniculate ganglion, taste is lost in the anterior two-thirds of the tongue on the
affected side. The saliva is diminished and the tactile sense of the tongue
may be impaired. Auditory disturbance may occur due to concurrent aural
lesions but the hearing, especially for low notes, may be rendered more acute
by paralysis of the stapedius muscle. Herpes may be present.
The electric reaction in mild cases may remain normal in the paralyzed
muscles, and here recovery within a few weeks is usual. In more severe cases
the electric reaction in the nerves is diminished while in the nerves, after a
few weeks, the reaction to direct galvanic stimulation is increased, the anodal
closure contraction exceeding the cathodal, and the response to stimulation
is delayed. Here recovery is less rapid but is likely to be complete in a month
or two. In very marked cases complete reaction of degeneration is present,
the course of the disease is much more protracted and may last for a year or
more. Relapses may occur. When brain tumor or necrosis of the petrous
portion of the temporal bone are aetiological factors the paralysis may be
Treatment should be directed at the cause of the condition. In syphilitic
cases the administration of the iodides in gradually increasing doses is indi-
cated. If the paralysis is due to lesions of the middle ear these should receive
appropriate treatment. When pressure is responsible its cause should be
removed if possible. When the disease is the result of exposure the salicylates
in large doses should be given and warm compresses, wet or dry, should be
applied to the face; later counterirritation by means of the thermo-cautery
or vesicants is useful. The hypodermatic exhibition of strychnine sulphate
in doses of 3^ to 2V of a grain (0.002-0.003) daily or every two days may
prove useful and salicin, 20 to 30 grains (1.3-2.0) three times a day or sodium
salicylate in similar dosage may be prescribed with benefit. In the later
stages electricity should be employed; galvanism is to be preferred; the current
should not be strong and it may be applied over the affected muscles and also
administered by placing the poles alternately below and in front of the ear.
784 DISEASES OF THE NERVOUS SYSTEM.
and interrupting the current about every fifteen or twenty seconds. Massage
of the facial muscles may also be employed.
Nerve anastomosis is indicated in cases in which the continuity of the
nerve has been destroyed by injury or by disease, after electricity has been
faithfully used for several months without sign of return of function. The
anastomosis is made with the hypoglossal or the spinal accessory nerve and
while complete recovery may not take place, the operation is likely to restore
the power of the affected muscles to a considerable extent and to greatly
mitigate the deformity.
Spasm. Facial spasm, mimic spasm or convulsive tic may be unilateral
or bilateral and consists of a clonic contraction of one or more of the muscles
innervated by the seventh nerve. Habit spasm is an analogous affection,
occurring usually in children as a result of "making faces."
The cause is indefinite, but the condition has been considered as due to
exposure, to pressure at the base of the brain from tumor or aneiu^ysm or to
a lesion of the facial center in the cerebral cortex. Reflex cases also occur,
due to decayed teeth, intestinal worms or sexual disorders. The condition
usually involves only one or two branches of the nerve, especially those supply-
ing the orbicularis muscle (blepharospasm) and the neighboring muscles.
Here there is twitching of the eyelid often with accompanying spasm of the
muscles of the side of the face. The angle of the mouth may be twitched
downward and the contractions may also involve the muscles of mastication,
the tongue and the platysma. The spasms occur spontaneously, are not
painful, and last for shorter or longer periods. They may be so continuous
that, while the patient is awake, his face exhibits constant twitchings. The
contractions are increased by physical or mental fatigue and by undue emotion.
Pressure over various points along the course of the nerve may elicit pain.
A tonic form of the disorder may occur with paralysis or from cold or, more
often reflexly, from some disturbance of the eye.
The prognosis of facial spasm is not favorable although intermissions
may be observed.
Treatment consists in removing all possible causes of reflex irritation,
especially in the eyes and teeth. Counterirritation may be applied along
the course of the nerve and especially over the points which are tender upon
pressure. Here the Paquelin cautery and vesicants may be useful. Freez-
ing of the affected cheek with the ethyl chloride, rhigolene or aether spray
for a few moments daily may prove beneficial, temporarily at least. Hypo-
dermatic injections of strychnine have been recommended and such drugs
as potassium iodide, arsenic, iron, atropine and curare may be employed
but it is doubtful if they will cause improvement. Nerve sedatives, the
bromides, hyoscyamus or codeine may be given.
Electricity in the form of galvanism may be employed, the anode being
DISEASES OF THE EIGHTH PAIR: THE AUDITORY NERVES. 785
placed over the tender points or along the nerve trunk. Reflex cases may
be benefited by applying the positive pole to the nuchal region while the nega-
tive pole is held in the hand.
Surgical interference consisting of division of the nerve and making an
anastomosis between it and the eleventh nerve, has been advocated. Nerve
stretching may afford relief although this may be but transient, the spasm
recurring when the paralytic effect of the stretching has passed.
DISEASES OF THE EIGHTH PAIR: THE AUDITORY NERVES.
Affections of the eighth nerve may result from lesions in any part of its
course. Disease at its nucleus of origin is rare; in its course it is subject
to involvement in fractures, tumors, inflammations or haemorrhages and in-
flammation of the nerve itself occurs as a complication of the infectious
diseases, locomotor ataxia and cerebrospinal meningitis.
The two branches of the nerve should be considered separately since the
cochlear is concerned in audition and the vestibvflar in coordination.
The Cochlear Nerve. Lesions such as tumor at the cortical auditory center
in the temporo-sphenoidal lobe, when on the left side, cause word deafness;
those involving the course of the cochlear nerve from the auditory center
to its origin result in true deafness.
Pressure upon the nerve at the base of the brain from tumors, aneurysms,
inflammatory exudates, haemorrhage, or injuries, and degeneration of the nerve
such as occurs in locomotor ataxia, may produce lesions of the nerve in its
course. Deafness also may be caused by the effects of epidemic cerebrospinal
meningitis upon the nerve.
Affections of the internal ear, primary or as a result of middle ear lesions,
are the most frequent causes of disorders of the auditory nerve.
The symptoms produced by lesions of the cochlear branch are a, auditory
hyperassthesia; h, irritation of the auditory nerve; c, nervous deafness.
Auditory hyperesthesia (hyperacusis) is a condition in which sounds inaud-
ible to the normal individual become audible and ordinary sounds are heard
with an increased intensity. Dysasthesia (dysacusis) is a condition charac-
terized by discomfort upon hearing ordinary sounds, as in headache when
a sound, such as would have no effect under normal conditions, increases
the pain. These affections may occur in hysterical conditions and in cere-
Treatment should be directed at the cause of the condition and the unpleasant
symptoms may be controlled by sedatives such as the bromides and valerian.
Auditory Irritation (tinnitus aurium). Under the general term tinnitus
are classified all forms of abnormal subjective sensation to which the ear
is subject, including ringing, buzzing, hissing, roaring sounds, etc. Even
JQO DISEASES OF THE NERVOUS SYSTEM.
the sound of voices may be heard. The sounds vary from those hardly
noticeable to those that cause profound discomfort. Bruits may be heard
synchronous with the cardiac systole and may be audible through the stetho-
scope applied behind the ear, clicking sounds, at times perceptible to the
patient's companions may be caused by spasm of the palate muscles. The
auditory aura, occurring sometimes in epilepsy, is a form of this trouble.
The mfsery induced by such conditions has been known to result in suicide.
The aetiology may be diiScult to discover. The ear should always be
examined for accumulations of cerumen and for middle ear disease. Gouty,
anaemic and neurasthenic conditions are often responsible for tinnitus, as is
the administration of quinine and salicylic acid in large doses.
Treatment consists in measures calculated to relieve any existing aural
lesion, such as the removal of impacted cerumen, the exhibition of the salic-
ylates, the iodides and colchicium in rheumatic and gouty cases and of iron
and arsenic when anaemia seems responsible. Neurasthenia should receive
appropriate treatment and the patient's nutrition and general hygiene should
The application of vesicants or even of the actual cautery behind the ear,
and the bromides, either alone or in connection with small doses of belladonna
are said to be useful. Glyceryl nitrate in ascending doses until the physiolog-
ical effect, as evidenced by feeling of fulness in the head and dizziness is noted,
is also recommended.
Nervous deafness is evidenced by diminution of the ability to hear sounds
when conducted by the air, while sounds conducted through the temporal
bone are audible. The test consists in holding the tuning fork near the ear,
then placing it in contact with the temporal bone. If it is not heard in the
latter case the loss of the power of hearing is not due to nerve deafness.
Treatment is likely to be of little avail. The otologist should be consulted
and a careful examination of the organ made, and the management of the
condition belongs rather to the domain of the specialist than to that of the
physician. Antisyphilitic treatment should be given when indicated and
electricity and mild counter irritation have a field of usefulness.
The Vestibular Nerve. Disturbances of this structure are evidenced by
vertigo, nystagmus and disorders in the function of coordination in the head,
neck, and eyes.
Meniere's disease or aural vertigo is a condition resulting from a lesion
of the lab}T:inth. Its pathology is indefinite; it occurs much more frequently in
m.en than in women and is most often observed between the ages of thirty and
sixty years. Exposure, syphilis and gout have been considered setiological
factors and the degeneration occurring in such affections as locomotor ataxia
and that of senility, as well as vaso-motor disturbances of the lab)Tinthine
vessels, seem to have influence in its causation.
THE GLOSSOPHARYNGEAL NERVES.
Symptoms. The onset of a paroxysm is usually sudden and may occur
without assignable cause or be induced by coughing or sneezing. Between
the attacks the patient may suffer from slight dizziness. The paroxysm is
characterized by sudden buzzing noises in the ears and marked vertigo, in
which the patient feels as if he were staggering or falling, the surrounding
objects may seem to be turning about and he may grasp at stationary objects
to prevent himself from falling or may lose consciousness for a few seconds.
After a moment or two the dizziness passes, the patient being left faint, pale
and nauseated with the face bathed in clammy perspiration. Aural symptoms
such as tinnitus and deafness in one or both ears may occur and double vision
or nystagmus may be coincident. The deafness is never complete, is of
nervous type and the tinnitus is throbbing or roaring in character.
The paroxysms appear at intervals varying from a few days to a few weeks
or even months.
The prognosis depends upon the cause. If this can be eliminated recovery
is possible and at any rate improvement may be expected. In less favorable
cases deafness results, which when complete is unaccompanied by dizziness.
The disease should not be confounded with epidemic paralytic vertigo
(Gerlier's disease or kubisagari) â€” see p. 207 â€” or with gastric vertigo, which
is not accompanied with deafness.
Treatment consists in relieving the cause of the condition in so far as pos-
The eyes should always be examined for errors of refraction, correction of
which may afford relief. Gouty patients should receive the salicylates, colchi-
cum and the iodides; the first of these should not be given in sufficient dosage
to induce tinnitus. Syphilitic cases should receive appropriate medication.
When contraction of the general arterial system is present glyceryl nitrate or
potassium iodide is indicated. Potassium bromide in doses of 15 to 30 grains
(1.0-2.0) three times a day may be employed and Charcot has recommended
the administration of quinine beginning with moderate doses and gradually in-
creasing them until cinchonism is produced.
Counterirritation behind the ears in the form of blisters may prove temporar-
DISEASES OF THE NINTH PAIR: THE GLOSSOPHARYNGEAL
Branches from this pair of nerves supply sensory fibres to the upper
part of the pharynx, the tonsils and soft palate, innervate the stylophar-
yngeus and middle constrictor of the pharynx and send taste fibres to the
palate and posterior third of the tongue.
Lesions of the glossopharyngeal nerve result from tumors, meningitis and
788 DISEASES OF THE NERVOUS SYSTEM.
degenerative processes; the nerve is seldom affected separately because of its
communications with others of the cranial nerves.
The symptoms of disturbance of the functions of this nerve are ansesthesia
of the parts supplied by its sensory fibres, paralysis of the stylophar^'ngeus
and middle pharv^ngeal constrictor, as evidenced by difiiculty in swallowing,
and gustatory disorders of the posterior third of the tongue and the palate.
Loss of taste sense â€” ageusia â€” results from disorder of the end organs in the
mucous membrane of the tongue caused by the habitual use of strong con-
diments such as pepper or of irritating substances such as tobacco; it also
occurs in the dr}^ tongue of febrile disease and the coated tongue observed
in alimentar}^ disturbances. Ageusia is a symptom of affections of the lingual
branch of the fifth nerve, of the trunk of the fifth before it leaves the skull,
of the seventh nerve between its union with the chorda tympani and the gen-
iculate ganglion, and of certain cerebral lesions.
Perversion of taste sense (parageusia) is met but rarely and then as a
symptom of hysteria or insanity. Subjective sensations of taste also occur
in the insane and as an epileptic aura.
The sense of taste is tested by causing the patient to close his eyes and
applying such substances as quinine, sugar solution, salt solution and vinegar
to the anterior and posterior parts of the tongue. A feeble galvanic current
gives a metallic taste and is a useful test. It is important that the test should
be decided while the tongue is protruded.
DISEASES OF THE TENTH PAIR: THE PNEUMOGASTRIC OR
The extensive distribution of this pair of nerves renders them liable to a
variety of disturbances. Their nuclei of origin in the floor of the fourth ven-
tricle may be involved in bulbar palsy, they may be subjected to pressure in
meningitis, syphilitic or other new growths, abscess, aneur^'sms or haemor-
rhages. Their branches inside the skull are subject to pressure from var-
ious intracranial lesions; extracranial branches are subject to traumatism,
to pressure from inflammatory processes, tumors and aneurysm, and may be
involved in true neuritis.
The pharyngeal branches may be paralyzed in bulbar paralysis or in neuritis,
especially that resulting from diphtheria. If but one side is affected the
disturbance of swallowing is but slight; in involvement of both sides degluti-
tion is attended with difficulty and liquids may regurgitate from the nostrils.
Spasm of the muscles of deglutition occurs in hysteria and in true and pseudo-
The laryngeal branches. The laryngeal paralyses occurring in vagus
lesions are of several tj-pes: Unilateral abductor paralysis is most frequently
THE PNEtJMOGASTRIC OR VAGUS NERVES.
caused by aneurysm, particularly of the arch of the aorta, since the recurrent