In cases of fracture and where there is reason to suspect a cortical or men-
ingeal haemorrhage, trephining of the skull and relief of the pressure is justi-
fiable and the results obtained are often excellent.
EMBOLISM AND THROMBOSIS OF THE CEREBRAL ARTERIES.
Synonym. Acute Cerebral Softening.
Definition. Embolism is the term applied to the plugging of a blood-vessel
by a clot or other foreign body brought to its place of lodgment by the
blood current.
By thrombosis is meant the stoppage of a blood-vessel by a clot developed
in situ.
iEtiology. Embolism is seen somewhat more often in females, thrombosis
in males; embolism may occiu* in children or young persons while thrombosis
is rare before middle life. Predisposing causes are acute or chronic valvular
heart lesions, aneurysm, endarteritis, blood diseases, acute infectious diseases
and pregnancy. The embolus is carried by the most direct route to the cere-
bral circulation, i.e., through one of the carotids, more particularly the left,
to the internal carotid and thence to the left middle cerebral artery, or less
frequently to the posterior cerebral branch of the vertebral artery.
Thrombosis is predisposed to by arteritis due to any cause, weak or fatty
heart and blood dyscrasiae; carotid ligation may be followed by cerebral throm-
bosis. The vessel most frequently involved is the middle cerebral; the basilar
artery is a not uncommon situation for thrombosis, less often is there obstruc-
tion in the vertebral and posterior cerebral arteries and in one of the various
branches of the circle of Willis.
Pathology. The stoppage of the blood current by the embolus or thrombus
deprives a certain area of the brain of its blood supply. Degeneration and soft-
ening of this area begin usually in about twenty-four hours. If in the gray
matter the tissue supplied by the occluded vessel becomes red (red softening)
and later yellow (yellow softening). The area of softening is finally absorbed,
a scar or a cyst remaining unless the embolus is infective when local inflam-
mation or abscess may result. The arteries in cases of thrombosis usually
give evidence of endarteritis affecting chiefly the cerebral arteries, anterior,
middle and posterior, as well as the vertebral and basilar arteries. Post-
thrombotic softening is analogous to that following embolisn and the two
conditions may co- exist owing to the detachment of a bit of the clot and its-
EMBOLISM AND THROMBOSIS OF THE CEREBRAL ARTERIES. 72 1
subsequent lodgment; rupture of one of the cerebral vessels may follow
either thrombosis or embolism.
Symptoms. Both embolism and thrombosis may take place without
causing recognizable symptoms if the condition occurs in a vessel possessing
free anastomoses, since a collateral circulation is immediately set up. When,
however, there is a stoppage in a terminal artery the picture is a markedly
different one. Prodromal symptoms seldom occur in embolism. The onset
may be marked by slight muscular twitchings with subsequent coma and
hemiplegia, the two latter manifestations alone may appear, or the coma
may be entirely absent. The suffused facies, stertor and arterial tension
characteristic of haemorrhage are absent. Vomiting is a rare symptom.
Prodromata are the rule in thrombosis; headache, dizziness, disturbances
of the cranial nerves, numbness and tingling of the extremities, and temporary
paralyses or aphasia may be observed. Here the coma and hemiplegia are
of gradual development in most cases but these symptoms may appear sud-
denly; the coma may be wholly lacking. The temperature is not markedly
disturbed but may be subnormal at first and rise later.- When a terminal
vessel is not involved the paralysis soon begins to improve, owing to the estab-
lishment of a collateral circulation.
In marked cases with considerable areas of softening the patient may die
within a day or two; death in less severe cases may not take place for a number
of weeks or the patient may pass on to the chronic stage, a state closely allied
in symptoms to that following cerebral haemorrhage.
The differential diagnosis has been discussed upon p. 718.
The prognosis in embolism is good, as a rule, as regards recovery unless the
obstruction has lodged in a very large artery, when the condition ends in death.
Recurrences in both embolism and thrombosis may occur, more commonly
in the latter, and each attack is more serious than the preceding. The prog-
nosis of the chronic stage is poor, as regards recovery, in both conditions.
Treatment. The patient should be put to bed with his head elevated.
Venesection is contraindicated but the heart action should be stimulated if
necessary by means of glyceryl nitrate, digitalis or strophanthus; the two
latter are particularly indicated in embolism, the first in tlirombosis. Potas-
sium iodide is also useful in relaxing arterial tension and is likely to be more
permanent in its effect than glyceryl nitrate. The dose of the former is 10
grains (0.66) or more, that of the latter, gr. ^ho to gr. Jg (0.0006-0.0012) three
times a day. The action of the bowels and kidneys should be maintained
in as nearly a normal state as possible. When there is possibility of a syphilitic
element in the aetiology of the condition treatment by means of mercury and
the iodides should be at once instituted.
The management of the chronic stage is identical with that of the corre-
sponding state in cerebral haemorrhage. (See p. 719.)
46
722 DISEASES OF THE NERVOUS SYSTEM.
THROMBOSIS OF THE VENOUS SINUSES OF THE BRAIN.
Sinus thrombosis occurs in both a primary and a secondary form. The
former is seen in "states of poor bodily nutrition and weakened conditions.
It may take place in infants as a result of chronic wasting diseases, especially
in diarrhoeal conditions, it may result from various blood dyscrasiae, and
may complicate such constitutional diseases as tuberculosis and cancer.
Secondary thrombosis is observed as a complication of various inflammatory
conditions'in the neighborhood of a sinus, such as internal ear and mastoid
disease, fractures of the skull and any suppurative process.
Symptoms. Primary thrombosis may be attended by few or no symp-
toms; those most frequently seen are headache, nausea, vomiting and coma
of very gradual development. Paralyses and pupillary dilatation are more
rare.
Secondary sinus thrombosis is preceded by otitis, cranial fracture, etc., and
their attendant symptoms; its nature is infective and it is usually ushered in
by a chill followed by a rise in temperature. There is severe occipital head-
ache, the patient may be stuporous or delirious, and convulsions may take
place as well as the other symptoms of meningeal inflammation. The sinuses
involved are usually those in the neighborhood of the ear.
The prognosis is serious, death in the secondary form usually occurring
after two or three weeks and often being due to septic pneumonia, which has
its origin in emboli brought from the affected sinus to the lung by the venous
circulation.
Treatment consists, in the primary form, of such measures as are called
for by the causative factor; in the secondary variety surgical procedures must
be employed with a view to the removal of the septic focus. For a descrip-
tion of these the reader is referred to works upon surgery and operative
otology. After treatment calculated to improve the patient's general condition
— quinine, iron, strychnine, etc. — should be employed.
APHASIA.
This is the term applied to defects or loss of the power of speech; it occurs
in a number of forms differing with the part of the speech mechanism affected.
In considering aphasia we include the faculty of transmitting to others our
thoughts by spoken or written words and by gestures, as well as the faculties
by which we see, hear and realize the significance of objects. Aphasia is
regarded as sensory or motor according as it is the result of inability to remem-
ber words or to speak them, consequently it may be caused by disorder of
either the receptive or the emissive center.
Sensory aphasia. Under this term we include word blindness, word
deafness and amnesic aphasia. Word blindness is the term applied to failure
GENERAL PARALYSIS, 723
to remember the appearance of a word. The patient afflicted with this con-
dition does not recognize the written or printed word while he may be able
to pronounce it when repeated by another, to copy it or write it from dictation;
the memory for figures, however, may remain normal. Motor aphasia may
co-exist with this affection and the portion of the brain at fault is believed to
be some part of the left angular or supramarginal convolution.
Word deafness is a condition in which, while the sense of hearing remains
undisturbed, the meaning of words is lost; musical tones also may be unrec-
ognized. This is a rare affection and is usually accompanied by other varie-
ties of sensory aphasia although it may occur independently. The part of
the brain affected is the posterior part of the first and second left temporal
convolutions in right-handed individuals and a corresponding area on the
right hemisphere in the left-handed.
Amnesic aphasia is a state in which the patient is unable to remember a
word; if it is supplied to him he recognizes and repeats it. He may be thus
affected as regards all words or only a few, perhaps but a single one, his name
for instance.
Agraphia is an analogous condition in which the patient is unable to write
a word because he cannot remember it; he can, however, usually write at
dictation.
These last two affections are probably caused by a disturbance of the asso-
ciation tracts.
Motor or ataxic aphasia. In this disorder the patient is quite aware of
the word he desires to say but is wholly unable to say it, neither can he,
if it is supplied by a second person, repeat it. If he is a linguist he may lose
the power of all tongues save one; he may be able to read to himself and under-
stand the speech of others while entirely unable to speak himself, or while
able to articulate a few words, he may mispronounce these or leave out syllables
or letters. In this condition the lesion is in the third left frontal convolution
and consequently is a frequent accompaniment of right hemiplegia. Alexia
or lack of the power to read aloud is usually an accompaniment of this form
of aphasia.
Atypical and mixed forms of aphasia are not unusual, a patient sometimes
using the wrong word to express an idea because of a confusion of thought.
GENERAL PARALYSIS.
Synonyms. General Paresis; Dementia Paralytica; Chronic Diffuse Men-
ingo-encephalitis; Paretic Dementia.
Definition. A chronic progressive inflammatory disease of the central
nervous system, especially of the cerebrum and its pia mater, resulting in
loss of mental and physical power and ending in insanity and paralysis.
724 DISEASES OF THE NERVOUS SYSTEM.
-Etiology. This disease is one of middle life and is more common in
males, although it has been observed in congenitally syphilitic children.
The chief causative factor is specific disease, syphilis being responsible for
at least 75 percent. — perhaps a much greater proportion — of all cases. It is
a disease of the higher classes of society and is predisposed to by excesses of
every variety, mental over-work and worry.
Pathology. The gross changes seen in the brain consist of atrophy, partic-
ularly involving the frontal lobes; their color is lighter and their texture more
firm than normal, the convolutions are shrunken, the fissures widened, cysts
may be present in both white and gray matter; there is also thickening of the
dura mater and of the pia. The latter is cedematous and may be adherent
to the brain. Upon microscopical examination the walls of the blood and
lymph vessels are seen to be thickened, the hypertrophy of the former resulting
in fusiform dilatations, and there is exudation of serum into the lymph spaces,
resulting finally in an oedema of the cerebrum. The nerve tissue itself is
destroyed and replaced by neuroglia. The cerebral neurons are' the seat
of degeneration and finally atrophy. These changes affect the cerebral
ganglia as well as the white and gray matter.
Sclerotic changes of the cord, analogous to those of tabes, particularly in
the posterior and lateral columns, are also present.
Symptoms. Those of the first stage or that of onset, may last for months
or even a year or more and are both mental and motor in character. The
patient is subject to delusions of grandeur accompanied by unusual actions,
loss of memory and lack of judgment. He may indulge in extravagant finan-
cial operations and make impossible promises or contracts; he may be
irritable and easily excitable or morose, and despondent; he may suffer from
insomnia. The motor disorders chiefly affect speech and handwriting.
The former becomes hesitating and indistinct, syllables and words may be
slurred and difficulty is experienced over complicated phrases such as " third
artillery brigade" and "around the rough and rugged rocks the ragged rascal
ran." The handwriting is shaky, syllables are omitted, words mispelled
and wrong letters inserted.
The pupils may be unequal, the patellar reflex may be absent in cases with
sclerosis of the posterior columns of the cord or it may be exaggerated in
spastic cases.
In the second stage the above symptoms are more intense, the mental state
may be violent or maniacal and the delusions more extraordinary, or, on the
other hand, the depression may become more marked, even to pronounced
melancholia, and the physical condition becomes much deteriorated. There
is progressive increase of the disturbance of speech and handwriting, the
former may become entirely incomprehensible and the power of writing entirely
lost. Epileptiform and apoplectiform seizures may occur, the gait is disor-
DISSEMINATED SCLEROSIS. 725
dered, and mono- or hemiplegia may develop. Ataxia, loss of sensation and
paralysis of bladder and rectum are not infrequent. Bulbar symptoms
follow and the patient becomes helpless, the loss of mental power is complete
and death supervenes from exhaustion or from concurrent disease.
The course of general paralysis is usually from three to six years but a
type of rapid coiurse is met in which the stages are shortened to a few
months; here the loss of flesh and strength takes place very rapidly.
The prognosis. While encouraging remissions in the development of
the symptoms occur at times the disease is bound to progress and the ultimate
fatal result is certain, consequently the prognosis as to recovery is wholly
bad.
Treatment. Institution treatment where a properly hygienic mode of life
can be carried out, with plenty of fresh air, bathing and massage, should be
insisted upon. While the action of antis)nphilitic treatment is in no sense
specific it may lessen the rapidity of the progress of the disease and in view
of the frequency of a luetic element in the aetiology, a course of treatment by
inunctions of merciury and the internal administration of pcrtassiura iodide
in increasing doses, even up to 100 or more grains (6.6) per day, should be
instituted.
Otherwise the treatment should be such as to combat the symptoms as
they arise; the excitability may be relieved by the bromides; for the sleepless-
ness the milder hypnotics such as sulphonmethane — gr. xx (1.33) — sulphon-
ethylmethane — gr. x (0.66.) — or veronal — gr. x to xv (0.66-1.0) — are indicated.
The attacks of marked deliriurh may necessitate the administration of
hyoscine hydrobromide, gr. y-g-Q (0.0006) hypodermatically. The bowels
should be kept open by laxatives if necessary and the patient's nutrition main-
tained by means of a nourishing and easily digestible diet.
DISSEMINATED SCLEROSIS.
Synonyms. Multiple Sclerosis; Instilar Sclerosis; Sclerose en Plaques.
Definition. A chronic inflammation of the central nervous system charac-
terized by the development of patches of sclerosis in various parts of the brain
and cord.
Etiology. The direct causation of this condition is unknown. It is
seen in both sexes with equal frequency, and, while it may occur at any age,
is rare in childhood and most common between the ages of twenty and forty.
It is said to follow the acute infectious diseases and also to result from ex-
posure to cold, emotional distiirbances and syphilis.
Pathology. Throughout the brain and spinal cord are irregularly scattered
patches of sclerosed tissue. These are grayish in color and firm in consis-
tency; their outline is irregular and distinct and their diameter may be ^^g- of
726 DISEASES OF THE NERVOUS SYSTEM.
an inch or more. They are rarely seen in the cortex, their usual sites in the
brain being about the lateral ventricles, the corpus callosum, the pons and
the cerebellum; they are infrequent in the pons but many may be found
in the cord, particularly in the white matter. The type of the sclerosis is
analogous to that occurring in other tissues; the neuroglia is increased at the
expense of the nerve cells and fibres and the walls of the blood-vessels are
thickened. When the process is advanced the nerve cells themselves become
degenerated and fatty granular cells may be present. In the nerve fibres
the white substance is first involved, later the axis cylinder, which ultimately
is wholly destroyed; this latter, however, is a late change, the axis cylinders
remaining intact long after their sheaths have succumbed to the sclerotic
process.
Symptoms. The occmrence of this disease with other lesions, together
with its slow development, renders its recognition diflScult. The symptoms
depend upon the portions of the nervous system involved in the sclerotic proc-
ess. An important early symptom is an ataxia of the limbs, resembling, in the
legs, the symptoms of spastic paraplegia with stiff and awkward gait, showing
that the pyramidal tracts are affected, here we find the patellar reflex and the
ankle clonus increased. The so-called intention-tremor is a typical symptom
manifesting itself by an incoordination of the hands, a marked tremor being
observed when the patient lifts a glass to the mouth or tries to pick up a small
object; the tremor ceases when the patient desists from his endeavor. A
like tremor affects the head and trunk. The Romberg symptom may be
present. Nystagmus and various ophthalmic disturbances are common;
these are due to sclerotic patches in the optic nerves or chiasm, and consist
of optic atrophy, amblyopia, loss of color sense, etc.; the Argyll-Robertson
pupil may be present.
The speech is characteristic, being the so-called syllabic utterance or
scanning speech, in which the syllables are separated by prolonged pauses; the
protruded tongue trembles and there may be difl&culty in swallowing.
While varying degrees of hemiplegia are not uncommon there is no mus-
cular atrophy; disturbances of cutaneous sensation are rare and if present are
very slight.
Headache and dizziness are sometimes observed and apoplectiform or
epileptiform attacks may occur. The mind is little if at all disordered,
although the memory may be slightly impaired; the intellect is sometimes
dull and there may be paroxysmal attacks of laughing or weeping.
Vesical disturbance and sexual weakness are not uncommon.
The course of the disease is variable, at times steadily progressing for a
year or two until it reaches a more or less permanent stage which may last
for a number of years; at other times the course may be characterized by
remissions but there is no hope of ultimate recovery.
ABSCESS OF THE BRAIN. 727
The prognosis as regards the patient's life is most serious in those cases in
which the sclerosis affects those portions of the nervous system in which the
vital centers are located — particularly the pons and medulla.
Treatment. We have no means by which we can check the development
of or cause to disappear the sclerotic patches; consequently the treatment is
chiefly symptomatic and sustaining. The administration of mercury and
potassium iodide should be instituted in all cases and may even benefit patients
in whom there is no history of syphilis. The hypodermatic employment of
arsenic and the use of silver nitrate internally have been recommended.
Tonics should be prescribed and the patient should lead a quiet, regular
life in accordance with the rules of general hygiene and his diet should be
nourishing and easily digestible. Massage, exercises, hydrotherapeutic
measures and electricity may prove useful both in treating the disease and in
giving the patient something to take his mind from his condition.
ABSCESS OF THE BRAIN.
Synonyms. Suppurative Encephalitis; Cerebritis.
Definition. A collection of pus or purulent fluid within the substance of
the brain or between it and its meninges.
jEtiology. Like abscesses of other parts, those of the brain are the result
of bacterial infection. The pathogenic micro-organisms find lodgment as
a result of a traumatism, as a result of an adjacent purulent process spreading
to the brain tissue or they may be brought from a distance by the blood stream
as in pyaemia.
Males are most frequently affected and the most susceptible age is between
ten and forty years.
Following injury, such as a compound cranial fracture, the abscess may
develop as a result of infection of the open wound; after contre coup fractures
the abscess may involve the tissues opposite or beneath the site of the trauma.
The most frequent cause of brain abscess is middle or internal ear disease,
especially when the tympanic cavity or mastoid cells are affected. Infective
processes of the nasal and orbital cavities also may result in brain abscess.
Pyaemia is a much less frequent cause; malignant endocarditis, tuberculous
inflammations of the lungs, empyaema, hepatic abscess, gangrene of the lungs,
etc., may produce abscess of the brain and the condition may complicate the
infectious fevers, enteric fever, smallpox, epidemic influenza, erysipelas and
the like.
Pathology. There is usually but one abscess although there may be two
or more. The most frequent location for those resulting from injury is in
the frontal or temporal lobes, those from nasal or orbital disease in the frontal
728 DISEASES or THE NERVOUS SYSTEM.
lobe, those from otitic inflammations in the cerebellum; embolic abscesses are
most commonly situated in the parts supplied by the middle cerebral artery.
The first change is a marked congestion which results in red softening. The
process continuing, the tissues become infiltrated with inflammatory exudate
and leucocytes. The resulting pus is greenish-yellow in color and of acid
reaction and consists of pus cells, disintegrated nerve fibres and cells, bac-
teria and granular detritus. The abscess varies in diameter from one-third
of an inch to three inches, and is surrounded by a fibrous wall con-
sisting of an inner layer composed of fatty granular cells, a middle layer
of germinal and fibrous tissue and an outer of fatty cells. Abscesses with no
such distinct wall may occur; these are more prone to spread than the encapsul-
ated variety. Abscesses near the surface of the brain may produce meningitis
by extension. Rupture of an abscess wall may take place, death resulting.
Certain cases of cerebritis do not proceed farther than the stage of red
softening, the exudate being absorbed and recovery ensuing with the formation
of an apoplectic cyst or a cicatrix.
Symptoms. The course of abscess of the brain may be either acute or
chronic; in the former type the disease runs its course within a few days.
The symptoms are those of increased intracranial pressure, such as headache,
dizziness, vomiting and mental hebetude or delirium, followed by coma.
Epileptiform convulsions may occur but are rather infrequent; the pupils
may be unequal. Toxic symptoms are superadded to those of pressure and
are those usually seen in septic conditions, such as an irregular temperature
curve, usually not every high, sometimes subnormal, chills, prostration and
emaciation. The pulse is usually slow — from 60 to 70. Symptoms of local
irritation such as paralyses or aphasia are not infrequent ; symptoms referable
to the cranial nerves, except the optic — optic atrophy not being uncommon —
are rare.
The symptoms of the chronic type are the same as those discussed above
but they develop much more slowly. Even after the abscess has been formed
there may be remissions during which the symptoms remain latent although
headache, irritability, dizziness and mild convulsions may persist. The periods