Section Iii. of the Brain.

=Inflammation.= Acute inflammation of the brain substance is a rare disease, except as the result of mechanical injury. In such cases, the disease is generally quite circumscribed, being confined to the immediate region of the injury. The brain becomes very vascular, acquiring a red color, which, at a later period, changes to a brown or greenish hue, and becomes much softer than natural.

If a foreign body be lodged in the brain, as a piece of bone, or a bullet, then the inflammation is likely to result in an abscess, which will give rise to head-ache, delirium with intolerance of light, succeeded by convulsions, coma and death.

Subacute, or chronic inflammation of the brain, is much more common, yet is accompanied with pathological changes similar to those of the acute form. At first, the inflamed portion becomes red and congested, the color gradually changing to a crimson, purple, brown, or claret color, with more or less change of consistence.

The symptoms attending inflammation of the brain substance, or cerebritis, are not readily distinguishable from those of meningitis; indeed, in most instances the two diseases are, to a certain extent, combined; as, from the vascular connection between the brain and pia mater, there might be a ready extension of inflammation from one to the other. When, however, there is any sudden perversion of the sense of vision or hearing; or if there are convulsions, affecting mainly one side of the body; or if coma succeeds the convulsions and is accompanied by one-sided paralysis, we may expect to find evidence of inflammation of the cerebral substance, with possibly that of the membranes also. It is a fact to be borne in mind, however, that while in typhus and typhoid, and perhaps some other forms of fever, we may have symptoms strongly resembling those of idiopathic inflammation of the brain or its membranes, still the post-mortem will reveal no trace of any such morbid condition.

=Softening.= To be able to recognize readily any change in the consistency of the brain, clear ideas must first be had of the normal density of this organ. This may be obtained from an examination of the brain of some of the lower animals—as the sheep or ox—that has been killed in a state of health. We shall then find that the brain presents sufficient firmness to permit of its being handled without rupture of its substance, and to allow of its being sliced into thin sections which will support their own weight. The gray portion is somewhat softer than the white, yet the fibrous character of the latter, becomes apparent only after hardening in alcohol. If put into pure water, it continues unchanged for eight or ten hours, and without any portion becoming dissolved, or rendering the water any degree turbid. The consistence of the brain varies, normally, at different periods of life. In the fœtus and at birth, its softness approaches to semi-fluidity. From this to the fifteenth or twentieth year, it gradually acquires the firmness of the brain of the adult.

=Softening=, one of the most common variations from the normal condition, is generally a mere result of inflammation of a chronic or sub-acute form, accompanied with a fatty degeneration of nerve substance. Under the microscope, the change is seen to consist in a disintegration of the nerve fibres, the medullary substance breaking up into large masses, and undergoing fatty metamorphosis. It may take place either on the external surface of the organ, or in the septum lucidum and fornix, the corpora striata, or optic thalami of the ventricle, the central parts of the hemispheres, the cerebellum, or the crura cerebri, in the order mentioned.

While this change is usually the result of inflammation, as already mentioned, it may accompany or succeed the following morbid conditions of the organ: 1. It may be the result of congestion of the vessels of some portion of the brain. In this case, the softened portion is reddish, crimson, or brown in color. 2. It may follow the effusion of blood in apoplexy. The softened portion is then of a brownish color, or, if considerable time has elapsed, it may be of a dirty ash color, tending to green. 3. It may accompany or follow the process which terminates in serous effusions. It is then of a milky-white color. 4. It may take place in the brain substance immediately around tumors, when its color may present a variety of tints.

Among the causes tending to induce this condition of the brain, may be mentioned a diseased state of its blood vessels, or their obstruction by fibrinous clots; constitutional syphilis; excessive mental labor, or frequently repeated epileptic convulsions. The consistency will be found to vary from a slight change from the normal condition, to that of a soft, pulpy, or even cream-like condition.

The symptoms accompanying softening of the brain, present a considerable variation. Among the more prominent, may be mentioned an unsteady or tottering gait, partial palsy, thick and inarticulate speech, feeble memory, disordered intellect, dull pain or heaviness in the head, frequent drowsiness, formication, numbness or rigidity, or occasional involuntary contraction of the muscles of the upper extremities.

=Abscess= of the brain, differs from softening, to which it may have some points of resemblance, in the purulent matter being contained in an irregular cavity, lined with a more or less distinct membranous cyst. Flakes of lymph are frequently found in these abscesses, giving the matter much the appearance of that contained in scrofulous abscesses, and they are most commonly found in subjects who present the usual symptoms of the strumous diathesis.

While these collections are unquestionably often the result of inflammation, yet it has been claimed that they may result from previous disease of a suppurative character in the lungs, and perhaps other organs, the purulent matter being taken up by the veins and carried into the general circulation, and finally deposited in the substance of the brain. Abscesses may be found in any portion of the brain substance, or the purulent accumulation may be found between the bone and dura mater, or between the two layers of the arachnoid. In the latter cases, the disease may generally be traced to caries of some of the bones of the head, as of the petrous or mastoid portions of the temporal, or of the bones of the nasal cavity, involving the cribriform portion of the ethmoid.

Again, abscesses in the brain may result from external violence, as from a blow or fall upon the head. It is remarkable, that in these cases, some months may elapse between the date of the injury and death.

=Hardening.= Induration of the cerebral substance, is a condition not readily distinguished during life from that of softening, the two states being accompanied by symptoms of a similar character. Dr. Jones, who has charge of the male department of the Pennsylvania Hospital for the Insane, and has had many opportunities for examining the brains of insane patients, tells me that he found hardening, nearly as frequently as softening, in these cases, and never could tell beforehand, with certainty, which condition might be present.

In hardening of this organ, its density may be increased to that of boiled white of egg, or it may approach in consistence to that of a brain that has been hardened in alcohol, losing much of the sticky, adhesive character when broken up by the fingers, which marks the brain substance when in its normal state. The cause of the change is not well known, yet it is conjectured to be one of the results of inflammation, inasmuch as it is generally found with its capillaries greatly loaded with blood, while more or less fluid is found beneath the arachnoid and in the ventricles. The induration may affect the greater part or even the whole of the cerebral mass, or may be confined to particular portions or regions.

In a case recently examined for Dr. Toothaker, of this city, where insanity of some years’ duration, and finally death, had followed a severe injury of the head, the brain was found so hard as to permit of fracture in the direction of the fibres, thus readily tracing their course.

The symptoms that have most frequently been observed to accompany this change are, defect and gradual loss of memory, apathetic indifference, slight difficulty of articulation, followed by loss of sexual desire, partial palsy, fatuity, wasting and death.

Extreme induration is often found in the brains of idiots. The whole organ may be found resembling in color and density boiled white of egg, or even cheese. The cerebral substance is shrunken, dense, and apparently quite void of vessels.

=Hypertrophy= of the brain, is a condition in which there is usually increased hardness as well as increased volume, and is distinguished by flattening of the convolutions, narrowing of the ventricles, and a remarkable dryness of the whole organ with its membranes, the change involving both the cerebrum and cerebellum, and accompanied with an increase of weight, all indicating increased nutrition, or the deposit of new matter in the tissue of the brain. Thinning of the cranial bones may attend this condition, increased internal pressure resulting in their partial absorption.

The causes of this form of disease are not generally understood. The symptoms, though always present, are not uniform. Among them may be mentioned intense head-aches, a weakened or perverted state of the intellectual faculties, fits of giddiness, accompanied with stupor; finally, convulsions, with perhaps loss of sensation and motion, the patient being unexpectedly cut off by an epileptic attack. The disease has not been observed in persons over fifty. In most cases, the patients were between twenty and thirty. In one instance, however, it was developed in a young girl of thirteen. Lead poisoning would seem to be an exciting cause, it having, in several instances, been developed in painters and manufacturers of white lead.

=Atrophy.= In this condition, there is found a general diminution of the volume of the brain, and especially of the convolutions. The latter are shrunk, narrow, and sometimes softened, while the sulci are large and open, the brain receding from the skull, and the pia mater greatly injected with serous fluid, giving the appearance of a jelly-like investment to the whole brain.

The brain substance is at the same time soft, the ventricles enlarged and filled with fluid, while a large amount of serum will flow from the sub-arachnoid space at the base of the brain, and from the spinal canal.

While this condition of the brain might be looked upon as a result of pressure from the accumulated serum, the absence of the usual symptoms of hydrocephalus, with the known history of these cases, renders it quite probable that the change commences as an actual loss of brain substance, the place of the latter being supplied with serous fluid.

Resulting from atrophy of the brain, there will often be found an increased thickness of the cranial bones, this being another conservative effort of nature to preserve the normal support and pressure upon the brain.

Atrophy of the brain is sometimes found in old age and in various enfeebling diseases, where all the organs suffer more or less waste from improper nutrition, but it is so frequently found with drunkards, especially those who have died with delirium tremens, that this condition may, in the large majority of cases, be considered as the effect of intemperance.

Several forms of atrophy may also be observed. It may be confined to some portion of the convoluted surface, or to one of the striated bodies or optic beds. Atrophy of the optic tracts, or nerves of one or both eyes, is not unfrequently associated with loss of sight from amaurosis.

Tumors of the Brain.

The brain, like other parts of the body, is subject to morbid growths of a great variety of forms. The symptoms of tumors in the brain, in many points, present such resemblances to other forms of disease, that it is usually the post-mortem alone, that will determine the fact of their presence or character. It may be said in general, however, that the effects of morbid growths in the brain will vary according: 1. To the changes in the surrounding cerebral substance; 2. To the size of the growth; and 3. To the position of the brain in which it may be developed.

1. The changes induced in the brain substance surrounding tumors are usually, first, derangement of the circulation, and second, as a result of this, effusion of serum, or finally, softening of a greater or lesser amount of contiguous cerebral substance. Head-ache, with epileptic attacks, loss of memory, irregular contraction of the muscles and partial paralysis may accompany the vascular derangement, while as softening or pulpy destruction supervenes, a general aggravation of all the symptoms will follow, ending in death, either with coma or by a sudden apoplectic attack.

2. Tumors of the brain of a small size, may be found after death from other causes, that have evidently produced no symptoms during life; and in other instances, they have induced no change until a few days before death, in which cases, the convulsions, paralysis and coma which precedes this result, must be attributed to the vascular disturbance in the surrounding brain tissue.

3. The position of the tumor, will modify to some extent the character of the symptoms manifested. When in the anterior lobes, loss or impairment of speech is said to attend. While, when in the corpus striatum, the motions of the legs and arms are disordered.

The following are the more commonly recognized tumors of the brain:

=Adenoid, or Glandular-like Tumors.= These are generally described as resembling an enlarged lymphatic gland, both in color and density. They may vary in size from a filbert to that of an orange. There may be a single growth of this kind, or several, and they may be found in any part of the brain.

=Tubercular or Scrofulous Tumors.= Under this head may be placed certain bodies of a white or pale yellow color, firm, like soft cheese, sometimes granular and friable, and consisting chiefly of a large proportion of albuminous matter. They may be found first, as one or more individual masses of considerable size; or second, sometimes as many minute rounded bodies, distinct and separate from one another.

In examining the head of a hydrocephalic child of four years, with Dr. von Tagan, we found attached to the underside of the middle lobe of the left hemisphere, a body of a white cheesy consistence, and of the size of half a hen’s egg. Connected with the cerebellum, was another tumor of the same character, but smaller in size.

Tubercular masses of this kind, may be found on the surface, or imbedded in the substance of any portion of the cerebrum or cerebellum.

The second form of tubercular deposits, are confined almost wholly to the gray matter of the surface. In one case, over two hundred of these bodies were found scattered through the gray matter of the cerebrum and cerebellum, of the size of a pea or bean, and of a pale yellow or bluish color. When cut open, the interior of the bodies was found to resemble boiled potatoes in consistency.

This form of disease is confined principally to children. Of thirty cases collected by Dr. P. H. Green, of London, all were between the ages of nineteen months and twelve years.

=Adipose Tumors.= Under this name, has been described a peculiar and quite rare form of disease of the brain, in which either some portion of the brain itself, or growths attached to or imbedded within the cerebral substance, present a fatty appearance, which by some has been denominated lardaceous degeneration. The exterior of the tumor is smooth, of a yellow color, and the interior composed of adipose matter of ash color, and semi-solid consistency.

=Cholesteroma.= This is another rare form of tumor of the brain, consisting of white pearl-like, glistening bodies, varying in size from that of a pea, to a walnut or small orange. They are found mostly at the back of the brain, and in the sub-arachnoid tissue. When examined chemically, the substance of these tumors is found to consist almost wholly of cholesterin.

=Cartilaginous Tumors.= These are often spoken of as scirrhus in their nature. They may be described as irregular in shape, sometimes lobulated, the interior yellowish in color, of a cartilaginous hardness, and arranged sometimes in streaks or bands, in other cases, in rounded masses. At a more advanced stage, from softening of the interior, cavities begin to form, which are filled with a semi-fluid or jelly-like substance. Death will generally ensue before this process is far advanced.

=Calcareous or Bony Deposits.= Osseous formations are not unfrequently found connected with the membranes of the brain, but rarely, if ever, with the brain substance. Calcareous deposits, on the other hand, have been found in almost every part of the brain. In the brain of an idiot of sixteen, the pons Varolii, crura cerebri and cerebellum, contained so much earthy matter, as to give difficulty in cutting with a knife (Sir E. Home.) In the brain of a man who had long suffered from acute pain in the head, a hard plaster-like concretion was found as large as a filbert.

These bodies are, therefore, not to be looked upon as genuine bony formations, but rather as an infiltration of chalky substance into the brain tissue. Of the same nature, are the calcareous deposits found in the pineal gland, which, although very constantly present after the age of eight or ten years, can hardly be considered as normal products, although it is well established that they exert no influence on the functions of the brain.

=Encysted Tumors, Hydatids.= A variety of tumors of the encysted form have been found in the brain by different observers, varying in size from a pea, to that of an egg or orange. Their contents also, have presented a great degree of variation. While some have been filled with the cheesy substance of the ordinary steatome, others have contained blood, a jelly-like, or even a limpid watery fluid.

It has been claimed by some, doubted by others, that the animal hydatid, the cysticercus, has been found in the human brain. Having unquestionably been observed in the eye, the heart, and other parts of the body, it may also, possibly, sometimes be found in the brain. This curious animal is now known to be but the larval form of one of the cestoid entozoa, the Tænia solium. Its position in the brain, can only be accounted for, by supposing that the embryo, which in its first stage is very minute, by piercing the coats of the stomach, into which the egg has been taken with the food, enters a blood-vessel, and being carried into the brain, lodges in some of the capillaries, the walls of which it penetrates. Entering thus the brain substance, it develops into the second larval form, which consists of a small bag or cyst, filled with a limpid fluid. Developed within the cyst, yet capable of being thrust out, is the head, which presents four sucker-like processes, surrounded by a circle of minute hooks, which give it the power of active migration through the tissues. In the pig, the presence of these cysticerci constitutes measly pork, which if taken into the stomach in a raw state, the contained larvæ at once develop into the perfect worm, the Tænia solium.

=Blood Cysts=, though not common, have been found in the brain. They consist of a membranous cyst, which may be lobulated or contain smaller cysts, the inner surfaces of which are lined with a vascular membrane, from which escapes a bloody fluid.

=Cancerous Tumors= may be found in any portion of the brain, and may present the several varieties of these malignant growths, including fungus hæmatodes. While they are generally secondary with similar tumors in other parts of the body, they may be primary in their origin. They may acquire such a development as to cause absorption of both the dura mater and skull, and thus appear upon the outside of the head. In fungus hæmatodes, the enclosed substance consists of soft spongy matter, of a brain-like consistency, divided into lobular masses, of a reddish shining aspect. They are mainly found in young subjects, sometimes in adults.

=Melanosis.= This form of morbid growth is occasionally found in the human brain. The middle lobe of the left hemisphere of the brain of a subject in the dissecting-room, was found to be attached to the dura mater by a melanotic mass, resembling the dark bodies frequently found around the bronchial tubes. Its attachments were such as to render it doubtful whether it had its origin in the brain or in its membranes. The gray substance of the brain of persons who have suffered malarial diseases, is sometimes found presenting a blackish appearance from the dark pigment within its substance, or within the pia mater.

=Syphilitic Tumors= are occasionally found in the brain, situated near its surface. Their characters are not such as to permit of their ready recognition, except when associated with syphilitic growths in other parts of the body. They may vary in size from a pin’s head to a cherry. They present a rounded or irregular form, a yellow color, and are composed of spindle-shaped or round cells, which may undergo a cheesy degeneration.

=Obstruction of Cerebral Arteries.= Patients suffering from endocardial inflammations, or from aneurism of the arch of the aorta, or from any cause having fibrinous deposits forming in the heart, are liable to have the same washed along the carotids, and thus carried into the vessels of the brain, thereby deranging the circulation through this organ. The symptoms resulting, are generally those of apoplexy. Hemiplegia, with or without loss of consciousness, follows. Softening of the cerebral substance follows as a result of the accident, and it is not impossible but that the presence of these bodies is the general cause of this structural change of the brain.

The position of the embolus, in fatal cases, is usually in one of the middle cerebral arteries; these vessels being in a more direct line with the internal carotids. They may lodge, however, in the vertebrals or basilar, yet through the circle of Willis, the several parts of the brain will still receive a partial supply of blood.

=Atheromatous Degeneration, and Calcification of Cerebral Arteries.= The coats of the arteries of the brain in old people, are liable to become infiltrated with atheromatous and calcareous matter to such a degree, as to render them rigid, and inelastic.

While the arteries of the base of the brain, as the basilar, the cerebrals, or the communicating of the circle of Willis, are more liable to this change, it may involve the smaller branches as well. The increased thickness of the coats of the vessels, results in a diminution of the calibre, while they are enlarged in external circumference.

Resulting from this state of the vessels, we shall have disturbed circulation, followed by effusion, and in some cases by atrophy of the brain. Attending this condition, are frequent attacks of stupor and insensibility, lasting for several hours or even days.

Again, from the weakened condition of the coats of the vessels in these cases, we may have an aneurism resulting, the walls of which suddenly giving away, death from hæmorrhage speedily follows.