CHAPTER II.

PATHOLOGICAL CONDITIONS.

Section I. OF THE SKULL.

[=Notice= in examination, condition of _scalp_; cuts, bruises, extravasation of blood, &c. _Cranium_—Color, smoothness or roughness of exposed surface; fractures, their position and relation to injuries of scalp. _Removal of Calvarium_—Adhesion of dura mater; inner surface of; smooth or rough; seat of same; deposit of new bone; depression of inner table; thickening or thinning of. State of fontanelles in children; condition of frontal sinuses; condition of base of skull noted after removal of brain; fractures; condition of petrous portions of temporal bones, &c.]

=Fracture.= In a post-mortem examination of the head, after death from a blow or fall upon that part, a fracture may be disclosed of which there was no external trace. Owing to the greater thinness and brittleness of the inner table, it is possible for this to be fractured without any corresponding injury to the external; such fracture may possibly rupture some of the branches of the meningeal arteries, which will be followed by the formation of a clot between the bone and dura mater, the pressure of which may be sufficient to produce death. Owing to the same cause—greater brittleness of the inner table—when fracture of the outer exists, that of the inner table will be likely to be more extensive, accompanied perhaps with depression, of which there is no external evidence.

Again, it will sometimes be discovered that fracture exists at a point opposite to that upon which the blow was received, on the principle of the “_contre coup_” of the French; thus, the blow having been received on the occiput, the fracture may be found in the frontal region; or, received on the top of the skull, fracture may result at the base. In falls from a height, upon the top of the head, the weight of the body, acting through the cervical vertebræ as a propelling force, is very likely to produce fracture of the occipital bone.

=Caries= may affect any of the bones of the head, but in the majority of cases it will be the result of syphilitic or mercurial poisoning. Following an attack of periostitis, the inflammation extends to the bone and gradually develops the carious ulceration. While the condition is usually confined to, or at least, most strongly developed upon the outer table, it may involve the entire thickness. In syphilitic ulceration of the bones of the nasal cavity, the disease may destroy the cribriform plate of the ethmoid bone, and thus extend to the membranes of the brain.[2] So also, in caries of the petrous and mastoid portions of the temporal bone, which sometimes results from scarlet fever, the disease may extend to the inner surface, resulting in the accumulation of pus within the cranial cavity.

Along either side of the central portion of the inner surface of the calvarium may be usually seen, at least in the heads of aged persons, a number of irregular, rough pits, varying in size and depth, which are not to be mistaken for disease of the bone, they being simply impressions of the _Pacchionian glands_.

=Thinning= of the bones of the head will always indicate _increased pressure_ from within, induced by hypertrophy of the brain, or, as is more frequent, hydrocephalus. In the latter case, not only thinning, but complete absorption of the parietal and other bones may result.[3]

=Increased Thickness= will also sometimes be found. This condition indicates _diminished pressure_ from within, as in atrophy of the brain. The thickening results from a gradual remodeling of the inner table and diploe, so that while the exterior of the skull may retain its normal size and form, the inner table following the retiring and shrinking brain, the interval between the two becomes filled with the thickened diploe. It has been observed that this hypertrophy is greatest at those parts of the bones where ossification first commences, as at the parietal and frontal eminences. It is not confined to old persons, though perhaps more frequent with them.[4]

Section II. THE MEMBRANES OF THE BRAIN.

1. The Dura Mater.

[=Notice= color and general character of surface; blood between it and bone; position of; quantity; coagulated or not. Condition of bone—necrosed or fractured; pus between dura mater and bone. Tumors—their position, size, &c. Wounds—their position, extent, &c. Open longitudinal sinus and note contents.]

This membrane, serving both as a periosteum to the inner surface of the cranial bones and as a support to a serous membrane—the reflected layer of the arachnoid—is subject to affections of a two-fold character, those peculiar to the fibrous and serous portions.

=Inflammation= of this membrane, may involve either the outer fibrous, or the inner serous layer. In the former case, the membrane appears congested, red and more or less softened. The inflammatory process may result in the formation of pus between the bone and dura mater, and even in gangrene. The disease may also extend to the adjacent portions of the pia mater and brain substance. External injuries, fractures of the bones of the skull, inflammation of the periosteum, otitis, resulting in caries of the temporal bone, may all be causes of inflammation of the outer portion of the dura mater.

Inflammation of the inner surface of this membrane, is marked by the presence of a net-work of delicate red vessels, while the surface is covered by a soft, grayish or yellow semi-purulent matter, and may attend cases of pyæmic poisoning, puerperal peritonitis, or some of the exanthemata.

=Thickening= of the fibrous portion of the dura mater may be found as a result of chronic inflammation, either spontaneous or as the result of external injury. From the identity of structure between this and other fibrous tissues of the body, it is not unlikely that this thickening is often the result of a rheumatic form of inflammation.

External violence is, however, most commonly the cause of the change. In one case, the patient fell down stairs in a state of intoxication, striking the head on the steps. He continued in a state of insensibility for nine days, when he began to show signs of returning consciousness, taking food and drink, but memory, judgment, and all the mental faculties were gone. Death ensued in about two years. The dura mater of the left hemisphere was found greatly thickened. The pia mater infiltrated with a large amount of serous fluid. The convolutions were atrophied, and about four ounces of serous fluid found in the ventricles. The _fornix_ was softened and the _septum lucidum_ entirely destroyed.

=Fibrinous Clots, or Thrombi=, will be occasionally found within the sinuses of the dura mater, where they may have given rise to congestion of the brain, with apoplectic effusions, paralysis, convulsions, coma, etc. They may originate from injuries of the head, inflammation of the dura mater, pulmonary disease, etc.

=Tubercular Deposits= are also sometimes found in this membrane, appearing, however, mainly upon the arachnoid surface. They present the usual character of tubercle, having a whitish or grayish appearance, with the consistence of cheese, and scattered in small particles upon the surface. They are found in _tubercular meningitis_, (a disease common with children but rare with adults,) and in most of those cases of so-called acute hydrocephalus.

=Tumors= of various kinds are occasionally found in the dura mater, including _cystic_, _fibrous_, _fatty_, _osseous_ and _cancerous_ growths. The latter may cause such absorption of the bones of the skull, as to appear on the exterior of the head.

In one case which came into the dissecting-room some years ago, thin _bony formations_ of the size of a silver quarter dollar were found in the tentorium, and smaller ones in the falx cerebri. Nothing could be learned of the previous history of the case.

2. Arachnoid and Pia Mater.

[=Notice= in examination, contents of cavity of arachnoid; serum or blood; if former, amount, color, odor; if blood, situation, quantity, fluid or coagulated; adhesion of surfaces of arachnoid; tubercles, their position, &c.; color of membrane; vascularity, transparency, or opacity. _Sub-arachnoid_ fluid—quantity, position, color, &c. _Pia mater_—vascularity, in points and entire; serous effusion into substance of; blood, &c.; position, size, &c., of clots; granulations, (tubercles,) number, position, &c.; Tumors—size, position, and character.]

As morbid conditions of the arachnoid membrane are more common with its visceral layer, and as these conditions usually involve the pia mater, the two membranes are here noticed together. They will be found presenting various degrees of congestion after death, which will not necessarily be a positive indication of the extent of congestion during life.

=Pacchionian Bodies.= Along either side of the great fissure may be noticed within the pia mater of adults, several small white bodies, varying in number and size—the _Pacchionian bodies_. They may cause absorption and perforation of the dura mater, and even of the bones of the skull. Being looked upon as the result of mere senile changes, they do not indicate the presence of disease, though repeated congestions of the brain appear to favor their more rapid development.

=Inflammation= of these membranes, or _meningitis_, is a very common affection, and is accompanied with an accumulation within its substance or beneath its layers, of serum, lymph, or fibrine in various proportions. It may be confined to circumscribed portions, or involve a large portion of the membrane, and even extend to the spinal cord. Adhesions between the two surfaces of the arachnoid sometimes result from this form of inflammation.

Insanity in its various forms is most frequently accompanied with some morbid condition of these membranes. In twenty-two cases of insane persons whose brains were inspected by Dr. Marshall, in twenty-one, serous fluid, varying in amount from one to twelve ounces, was found in the ventricles, and in seventeen of these twenty-one cases, similar effusion was found in the sub-arachnoid space, or within the substance of the pia mater. While red injection of the membrane was found only in four cases, yet other conditions—the effusions, &c.—were evidently the result of previous inflammation. In nine cases were the arteries of the brain opaque, thickened, steatomatous, or ossified; conditions highly favorable for deranging the capillary circulation of the membranes or of the brain.[5]

The following statement gives the principal morbid changes of these membranes which have been found in cases of insanity:

1. Injection, more or less intense, of the _pia mater_, giving a red or scarlet appearance; or, where infiltrated with serous fluid, presenting a pale gray color and increased in thickness.

2. The arachnoid (the visceral layer) becomes opaque and thickened, resembling the dura mater or macerated parchment.

3. The meningeal injection may terminate in serous effusion, either from the free surface of the arachnoid into the sub-arachnoid tissue, (pia mater,) or from the choroid plexus into the ventricles.

4. Albuminous exudations may be found upon the free surface of the arachnoid of the _dura mater_, covering its whole extent, or confined to definite portions.

5. Adhesions of the two surfaces of the arachnoid may rarely be found. It is most common in the great fissure, and has been found in the ventricles.

6. Blood may be effused upon the surface of the arachnoid or in the substance of the pia mater.

=Serous Effusion.= As has been already intimated, this may be found either in the cavity of the arachnoid—between the reflected and visceral layers—or within the ventricles. In the former position, the quantity is never large, while in the latter, it may amount to twelve or sixteen ounces, and be present for many years. When in such large quantity, there will be great distension of the ventricles and thinning of the corpus callosum and fornix, with destruction of the septum lucidum, as well as more or less separation of the cranial bones. It is only in children and before the bones of the head have become united, that such large accumulations are possible, as at a later period, from the unyielding condition of the walls of the skull, the presence of a single ounce, particularly if suddenly formed, would produce death. In all cases, the danger to life will be in proportion to the rapidity of the formation; a very slow and gradual accumulation permitting either of an expansion of the cranial bones, or a gradual absorption of brain substance, thus preserving an approximation to the normal pressure on the brain tissue.

Serous effusions, like sanguineous, are generally the result of over distension of the cerebral vessels, either from mechanical obstruction, or a weakened condition of the coats of the vessels, with increased force in the action of the heart. It generally attends tubercular meningitis, and may be favored by an anæmic condition of the system. The symptoms during life, attending a rapid effusion of serum, are not so readily distinguished from those of sanguineous effusion, as to enable us to pronounce with certainty in any given case as to the cause of the cerebral pressure.

=Sanguineous Effusion—Apoplexy.= Effusions of blood may be found between the bones and dura mater; between the two layers of the arachnoid; within the substance of the pia mater; within the ventricles, or within the brain substance. Blood clots will seldom be found between the bone and dura mater, except as a result of mechanical injury, and in the majority of cases as an attendant upon fracture. If a fragment of the bone at the same time, be driven through the dura mater, then a clot may be found in the arachnoid cavity. But in another class of cases, where death has resulted from blows upon the head without producing fracture of the bones, the whole surface of the brain in the region of the injury, and not unfrequently in distant parts, after the removal of the dura mater, is found covered with a layer of blood, which at first sight appears to be outside of the membranes; but on close examination, it is found that the blood is effused or infiltrated into the sub-arachnoid tissue, and that it has escaped from the lacerated vessels in the pia mater. The thickness of the layer varies. It is generally in greater quantities at the sides and base of the brain, and the inferior lobes and cerebellum may be covered by it. It is usually thickest over the crura, the pons Varolii and medulla oblongata.

In the same class of cases the blood may be also effused into the ventricles. These appearances are so uniformly the result of violence, as to form a valuable piece of evidence in medico-legal inquiries, to prove that such hæmorrhage and death could not be the result of internal causes.

In the greater number of _still-born_ children, an examination of the head will show a similar condition of things. The surface of the cerebrum generally, with sometimes that of the cerebellum, will be found covered with a layer of coagulated blood effused into the pia mater, while the ventricles will often be filled with clots. Where the history of the case is not known, it might at first be suspected that death was the result of violence inflicted after birth. Violence has, to be sure, been the cause of death, but it is such violence as attends a protracted case of labor, with, perhaps, a large head, and a contracted pelvis of the mother. The wonder is, that from the great pressure to which the head is subjected during labor, that so few children are still-born or do not die soon after birth, from rupture of the cerebral vessels.

Effusions into the ventricles, may also be frequently the result of external violence. The pia mater, the vascular membrane of the brain, we find carried into these cavities by means of the velum interpositum, which forms the roof to the third ventricle, while its borders extend into the lateral, forming the choroid plexuses. The effused blood may, therefore, extend along this membrane into the cavity of the ventricles.

Again, blood may be effused in any portion of the _brain substance_, constituting true sanguineous apoplexy. Certain parts are much more frequently the seat of these effusions than others. They are more common in the striated bodies or optic thalami—probably from the greater vascularity of those parts—but may be found in the corpora quadrigemina, the pons Varolii, the crura cerebri, or in the cerebral hemispheres, and occasionally in the cerebellum. The symptoms during life will vary according to the location of the effusion; when in the pia mater, or in other words, outside of the brain, paralysis will seldom attend, though the coma may be profound, with relaxation of the muscular system and sometimes convulsions. When the hæmorrhage is in the optic bed or striated body of one side, from the decussation of fibres in the medulla oblongata, paralysis of the opposite side of the body will follow; while if the effusion has taken place in both hemispheres, the palsy will be double-sided, though probably more complete on one side than on the other.

Effusions of blood into the corpora quadrigemina, will most frequently be attended with muscular tremblings or convulsions, and probably impaired sight, with some change in the pupil. When in the medulla oblongata, convulsions, followed by palsy, deep coma, and early death; greater fatality attending effusions at this point, probably, than at any other. When the effusion takes place in the cerebellum, the loss of consciousness will be very temporary; there may be relaxation of muscles without palsy or loss of sensibility, and, it is said, frequent vomiting.

The _amount_ of blood effused is subject to the greatest variation. Clots may be found as large as a hen’s egg, or smaller than a pea. Indeed, violent apoplectic attacks, ending in death, may occur, where the most careful examination will fail to detect _any_ effused blood, death being the result of extreme congestion of the membranes. On the other hand, the presence of a clot is not necessarily fatal, evidence being abundant that they may be so far reabsorbed as to be followed by at least partial recovery.

The following cases will serve to illustrate these several conditions:

CASE I.—_Sudden Death from Cerebral Congestion._

Mr. M——, aged thirty-five years, had always enjoyed good health. For some months previous to death, had been working very hard, with a good deal of anxiety, in arranging the affairs of a company of which he was secretary. On the evening previous to his attack, he retired at eleven o’clock, well and in good spirits. At three o’clock A. M., his wife was wakened by his heavy, stertorous breathing, attended with slight convulsive movements of the limbs. In less than a half hour he was dead. The post-mortem showed the heart, lungs, and abdominal organs to be in a perfectly healthy condition, while the most careful examination of every portion of the brain failed to expose the least effusion of blood. The ventricles and sub-arachnoid space contained a moderate amount of serum, while the vessels of the pia mater were strongly engorged with blood.

CASE II.—_Apoplectic Attack, followed by Death in Three Days; Clot found in Thalamus._

Mr. J——, aged sixty-one, a butcher, abstemious in his habits but plethoric in temperament, was suddenly stricken down with an attack of apoplexy, which left him with paralysis of the right side of the body, with impaired speech and memory. He gradually and almost entirely recovered. Ten months after, while in the street, he fell with another attack. He partially recovered consciousness, but had complete palsy of the _left_ side, and died in three days. Here, the post-mortem revealed excessive congestion of the pia mater, and a large clot, the size of a hickory nut, in the _right optic thalamus_. In the _left thalamus_ was a distinct trace of a clot, (nearly absorbed, however,) which had undoubtedly been effused in the attack ten months previously.

CASE III.—_Apoplectic attack, followed by Hemiplegia, and Death in Five Years._

Charles E. W——, at the age of forty-seven had a sudden apoplectic stroke, in January, 1867, followed by partial paralysis of right side. In May following, he had a second attack, which greatly increased the hemiplegia, impaired the articulation, and weakened the memory and intellect. His general health and strength gradually failing, he died August, 1872, five years after the original attack.

Post-mortem revealed a greatly thinned and dilated condition of the walls of the arteries of the base of the brain and the remnants of the original clot imbedded in the left optic thalamus, the brain substance around being of a dark color and much softened. From the appearance of the dark, ragged remnant of the clot, it must have been originally of about the size of a robin’s egg.

CASE IV.—_Death from Congestion, with Serous Effusion and Softening._

Mr. F. H——, aged thirty, had an attack of brain fever at twenty-three, followed by attacks of severe pain in the head, recurring every few days, weeks or months. These attacks were accompanied with slight convulsive symptoms and delirium, the pain being of a most excruciating character, and lasting from a few hours to two or three days. The attacks were gradually increasing in severity, but without any impairment of the faculties of the mind. On a Saturday night, he was brought home with one of his worst attacks. When I first saw the patient on Sunday evening, I found him in a half-delirious, stupid condition, yet when roused up, giving satisfactory answers to questions, but immediately sinking into his former condition, and every one to five minutes starting suddenly up and, with staring eyes and distorted face, uttering piercing shrieks and screams, and calling to those around to shoot him, split open his head with a hatchet—anything to release him from his sufferings. These paroxysms would sometimes be followed by a convulsive action of the diaphragm and abdominal muscles, ending in his sinking into the same dull, stupid condition as before. In the interval of calm, the respiration was remarkably slow and feeble, with a slow irregular pulse of forty beats to the minute. These symptoms becoming gradually worse, he sank into a comatose condition early Tuesday morning, expiring at daylight, sixty hours after the commencement of the attack.

The post-mortem revealed greatly enlarged Pacchionian glands, with extreme thinning of the skull over the same. The pia mater was considerably congested. Upon turning the brain back for removal from the base of the skull, there was a sudden gush of water from the ventricles, sufficient of which was secured to show that the quantity could not have been less than two ounces. Upon opening the lateral ventricles, these cavities were found unusually large from distension by the fluid, while the _septum lucidum_ and _fornix_ were found in a soft, pulpy condition, the former being completely broken down and detached from the corpus callosum above. The gray portions of the corpora striata were also softer and more easily broken up than was natural.

The appearance presented by a clot, as well as the brain substance immediately around it, will vary according to the time the patient survives the attack. When death follows in a few days, the clot will have a soft, blackish appearance; after a month or six weeks, it becomes firm, and assumes a deep brown color, and at a still later period, it becomes still more firm, and of a pale red tint; lastly, it may become entirely absorbed. Peculiar changes also take place in the brain substance immediately around the clot, which vary according to the time intervening between extravasation and death. The portion immediately in contact with the clot is generally of a dark red or wine color, or, at a later period, of a chocolate brown, and of a soft, pulpy consistency. Exterior to this, the color is paler and of an orange tint, and still further on, of a bluish-white or yellow. The change in _structure_ and _consistence_ of the brain, immediately around the clot, constitutes one form of softening soon to be noticed.

Section III. OF THE BRAIN.

[=Notice= _before removal_—size; form; symmetry; space between surface of brain and calvarium. _After removal_—parts at base, their size, symmetry, color on surface, infiltration with serum or blood. _Removal of pia mater_—degree of adhesion; appearance of convolutions; color; consistence; effect of stream of water. Ulcers—condition of brain around. Sloughs—relation to membranes, condition of brain around. Deposits; tumors, wounds, etc. _After section, notice_ breadth and character of gray portions of convolutions; color, vascularity, etc. _Consistency_—softened or hardened; of white substance; color. _Blood-vessels_—number and size of red points in different portions. _Extravasation of blood_—its situation; fluid or coagulated; amount or size of coagulum; color, etc. Cavities in brain substance; their number, shape and contents. Blood, purulent, or fluid; its quantity and color. Condition of brain around; cicatrices; wounds; adventitious substances, as tumors, calcareous masses, tubercle cancer, etc. _Lateral ventricles_—note any difference in the two; contents; amount of serum or blood. _Choroid plexus_—pale or congested; cysts; calcareous bodies; their size and situation. _Lining membrane_ of ventricles; its vascularity, roughness, opacity, etc. _Septum lucidum_—entire or lacerated; consistence. _Fifth ventricle_—size, contents, etc. _Third ventricle_; contents. Commissures—their condition; middle, broken or double. _Optic thalami and corpora striati_—size, symmetry; character of surface and interior; if softened, extent; extravasation of blood, etc. Condition of _pineal gland_; _corpora quadrigemina_; _valve of Vieussens_, _etc._ _Medulla oblongata_—degree of adhesion of membranes; softening, exact locality of; condition about origin of nerves; appearance upon section. _Fourth ventricle_—contents; condition of floor, etc. _Cerebellum_—examine with same care, and note same points as in cerebrum.]

=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.[6]

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.

Section IV. OF THE SPINAL CORD.

[=Notice= in examination. 1. _Vertebræ._—Condition of several parts; caries, etc. 2. _Vertebral Canal._—Proportion to cord; contained fluid; serum, pus or blood; amount, etc.; condition of spinal veins. 3. _Membranes of cord._—Bulging of any part; thickening; congestion; morbid growths, etc.; fluids within; amount, color, etc. 4. _Spinal cord._—Weight; size; condition of fissures; of interior, as seen on section; softening; exact point of; roots of nerves; pressure upon, etc.]

From the continuity and identity of structures, the spinal cord is subject to essentially the same diseases as those of the brain.

1. The Membranes.

=Inflammation= of the latter may exist alone, or in connection with that of the membranes of the brain, constituting _cerebro-spinal meningitis_. Inflammation of the dura mater is an uncommon occurrence. The inflammation in spinal meningitis is almost wholly confined to the pia mater, this being the more vascular of the membranes. A pale reddish, or sometimes purple color, with a bloody jelly-like infiltration, characterizes the earlier stage, while at a later period the membrane presents a greyish or dirty yellow appearance, from the presence of a thick pus-like substance covering the surface. Such inflammations may be either idiopathic, rheumatic or traumatic in their origin.

In _spotted fever_ the inflammation extends to the pia mater of the base of the brain, and is remarkable from the epidemic form which it sometimes assumes.

=Tubercular= deposits, as well as _tumors_ of various kinds, may be found connected with the spinal membranes, so similar to those described with the cerebral membranes, as not to require separate notice.

=Serous effusion= may be found in the spinal canal, in the same cases when it exists in the cranial cavity, and may be either a diffusion of fluid through the sub-arachnoid space, that has been effused in the brain, or it may originate from the membranes of the cord itself. The fluid may be either between the vertebræ and dura mater, or between the latter and the pia mater.

A peculiar form of dropsy of the spine is sometimes found, congenital in its nature, and accompanied with a deficiency in the spinal column, by means of which a cleft remains in the arch of one or more of the vertebræ; hence the name, _Spina bifida_, as applied to this disease. The effusion in these cases, taking place before the vertebræ are fully developed, the pressure from within prevents the final closure of the canal posteriorly; when, from want of support at that point, the membranes and covering tissues, yielding to the pressure from the accumulating fluid, gradually protrude at that point, producing a rounded fluctuating tumor. The disease is more frequently found in the lumbar region, although it may occur in the dorsal or cervical, and in some cases may involve the whole spinal column.

2. Spinal Marrow.

=Inflammation= of this structure, (_myelitis_,) presents the same character, and may be followed by the same results as inflammation of the brain. From the distension and engorgement of the capillaries of the inflamed part, a bright red color may be presented, not only on the surface, but in the substance of the cord when exposed by division. Blood may also be found effused in the substance of the cord, or between its membranes, or between the bony walls and the dura mater.

=Softening= of the spinal cord, may arise either spontaneously, or as a consequence of injury. When spontaneously taking place, a large portion of the cord may be involved. The appearance presented, is most usually that of a soft pulpy mass, which easily breaks down upon the opening of the membranes. When the result of injury, the softening is generally confined to the portion involved in the original violence.

=Hardening= of the spinal marrow, (_sclerosis_,) may be one of the results of inflammation, yet the accompanying symptoms may vary so slightly from those of other forms of spinal disease, that the post-mortem alone, will disclose the true nature of the difficulty. In _locomotor ataxy_, the posterior columns of the cord are usually affected with this change.

=Atrophy= of the spinal cord, differs from hardening, in the _shrinking_ which attends the progress of the disease, although there may be increased density, as in the former case. The essential peculiarity of atrophy, consists in an increased development of the fibrous elements of the cord, which by pressure, gradually destroys the elementary nerve constituents. This disease is confined chiefly to men of a middle age, and is generally the result of venereal excesses; muscular over-exertion, exposure to cold, &c., may also be exciting causes.

=Morbid Growths=, of various kinds, and closely resembling those found in the brain, as well as _animal parasites_, are sometimes found in the spinal cord.

PART II. THE NECK AND CHEST.