In a gumma in the cortical motor zone of the right side the head-temperatures, taken once, were found to be for the right parietal region, 97.2°; for the left, 96°. In another tumor of the right motor zone the right frontal region gave a temperature of 98°; the left, of 96°. In a tumor of the left occipito-parietal region the temperatures were for the right parietal region, 98°; for the left, 97.8°. Although the temperature of the head was only taken once in each of these three cases, the observations were carefully made with tested thermometers.
J. T. Eskridge, in a case of a tumor of the cerebellum with monocular hemianopia (Case 76), made the following temperature observations:
The normal average temperatures, as determined by Gray, were as follows:
We conclude that in brain tumors the average temperature of the whole head is elevated several degrees above the normal, and that the elevation of temperature is usually greatest at the station nearest the seat of the growth.
Mental disturbance of some description was present in about one-third of all the cases studied. Doubtless they were not recorded in a large number of cases. Obernier says: “If the psychical qualities of a patient suffering from cerebral tumor be analyzed, and a careful comparison made of the former with the existing mental condition, certain symptoms of mental disturbance will be discovered in most cases where the tumor is a growing one.†The disturbances may be in any sphere of the mind—in intellection, volition, emotion, or perception. Mental slowness and uncertainty, inability to fix the attention, impossibility of continuous mental action, apathy, or stupidity, with hesitation or slowness of speech, were strikingly exhibited in cases of tumor of the antero-frontal region. In Case 1 the patient's mental condition was studied with great care, and in the detailed report of the case23the following facts were noted: The psychical manifestations were among the most important features of the case. Although comparatively uneducated, he had been whenin health intelligent and energetic. He had never during his illness had the gay humor or delirium of grandeur seen in the general paralysis of the insane. His condition, on the whole, was one of intellectual slowness and uncertainty. He seemed to have great difficulty in receiving mental impressions and in directing the movements of his body. His faculty of attention was, in great measure, destroyed. It could only be fixed, and then but partially, by distinctly and vehemently repeating a question or command. He could hear, but it was necessary to make a tremendous external impression on his sense of hearing in order to call out a mental response. He sometimes appeared to me like a man dazed by a great catastrophe which he could not understand. He was not aphasic, although he manifested certain striking peculiarities of speech, or, rather, of the manner of speaking. What he said, either spontaneously or in answer to questions, was spoken clearly and distinctly and in a firm, loud voice. His sentences were short, but complete; neither words nor syllables were omitted; and he made no mistakes in articulation, enunciation, or pronunciation. In answering he did not seem to be able to retain for any length of time a hold upon the same idea or to follow a particular train of thought. He did not wander from one subject to another, but he would suddenly stop speaking, as if unable to go farther. Often on being questioned he would try to reply, and after a sentence or two would sob and burst into tears like a violently hysterical woman. He would at times have what might be termed volcanic outbursts of speech. When all was perfectly quiet in the ward he would suddenly explode with a sentence or two, and then again subside into stillness. Exclamations of this kind might be repeated at intervals of a few minutes for hours together, or they might recur only at intervals of hours. Sometimes what he said would be connected with some past events of which he seemed to have a vague recollection; often it would be a demand for something to eat or drink; and often, again, it would be a paroxysm of profanity.
23Philadelphia Medical Times, Jan. 18, 1879.
Impairment of will is not uncommon in antero-frontal and other cerebral tumors, and failure of memory, depression of spirits, and even acute mania, occur. Many of the patients are emotional, excitable, and irritable; they often sob and cry, apparently from the great pain. In some cases, however, emotional conditions are present which seem to be dependent on some special localization of the tumor. Hallucinations were noted in two of our tabulated cases. In one case, a tumor of the motor zone, the patient had delusions that some one was about to take him away. There were also illusions of fear or persecution. In another the patient had visual hallucinations.
Speech-defects of various kinds occur in connection with intracranial growths. Ladame, quoted by Rosenthal, has cited forty-five cases of disturbances of speech in which the tumor occupied the most varied regions of the brain. Peculiar disorders of speech from special localizations will be treated of under Local Diagnosis.
Local spasms, which go under various names, as cramps, twitchings, epileptoid attacks, athetosis or athetoid movements, are common symptoms, particularly of growths which involve the cortical motor area. They are of great diagnostic value. They are commonly, although not invariably, accompanied by paresis, which is usually most marked in thepart most affected by the spasm. These local spasms, beginning in one extremity, in a finger or toe it may be, often spread toward the centre, until they involve to a greater or less extent the whole limb, the side of the face, or one-half of the body. Sometimes instead of this they recur with the same definite movements over a long period. They are the expression of irritation of cerebral centres or tracts connected with the muscles or groups of muscles affected by the abnormal movement. They should always lead the physician to carefully consider the great probability of a lesion in some way involving the motor area.
Tumors of the cerebellum, pons, and medulla oblongata sometimes give rise to general convulsions which closely simulate attacks of grave epilepsy. These convulsions or general spasms are among the most important symptoms of intracranial neoplasms. More than paralysis, they may be regarded as general symptoms, as they are more likely to occur from tumors situated in different and distant regions of the brain than paralysis. They are by no means confined to cases in which the lesion is situated in the so-called motor area of the brain or in the cerebellum or pons-medulla region. Both physiological and pathological experiments have shown that convulsions violent in character, but having certain special characteristics, may originate from severe irritation of the dura mater. According to Duret,24irritation of the sensory nerves of the dura mater cause reflex spasms or contractures of the muscles of organic life. These spasms or contractures may occur in the face, eyeballs, neck, trunk, or limbs, and sometimes on one side and sometimes on the other. They tend to diffuse and invade neighboring groups of muscles. “They have never the localization, the measured and purposed character, of the contractions which belong to the lesions of the cortex. They frequently become transformed into permanent contractures.†The application of these facts and conclusions to brain tumors is evident. As neoplasms are so frequently connected, either directly with the dura mater or with the fused membranes, it is evident that the convulsive attacks from which the patient suffers may occur from tumors located anywhere within the cavity of the skull.
24Sur les Traumatismes cérébraux, par H. Duret, chapter iii., summarized inBrain. vol. i., 1878, p. 47.
General convulsions, as well as local or unilateral spasms, are present in many tumors of the motor cortex; but if their method of origin and their progress are closely watched they will usually be seen to begin with local twitchings.
A glance at the table will show examples of convulsion in almost every region of the brain.
Contractures—conditions of tonic spasm which continue more or less persistently—may be either early or late symptoms. They may occur in one or several limbs, in the face, or rarely in the neck. They are probably due in some cases to persistent irritation of the dura mater, in others to comparatively slight but continuous irritation of motor centres, and in still others to advanced degeneration of the motor tracts.
Choreas and choreic movements are not frequent, unless some of the forms of local spasm are regarded as local choreas. In one of Petrina's cases, a glioma involving the substance of both frontal lobes, choreic movements of the right arm were present, and in this same case tremorin both arms was also a symptom. Tremor simulating that of paralysis agitans or multiple cerebral sclerosis is occasionally observed, and sometimes a tremor which is nervous or hysteroidal in character is one of the results of the great suffering of the patient.
Paralysis or paresis is of course one of the most frequent evidences of the existence of an intracranial tumor. The palsies of cerebral tumors are chiefly unilateral, but the loss of power may be in one or both limbs, in one side of the face, or in the entire one-half of the body, according to location and extent. Tumors of the cortical motor zone usually begin their paralytic manifestations with paresis of one member or one side of the face, which goes on, as the growth increases in size, to more or less complete hemiplegia.
The paralysis which results from brain tumor is due either to pressure or to absolute destruction of tissue. In the latter case the destruction is brought about not only by the simple displacement of brain-substance, but also through the obliteration of blood-vessels and the consequent softening.
Peculiar forms of paralysis occur as the result of neoplasm growing in special locations, as will be more clearly shown under Local Diagnosis. Thus we have the alternating paralyses from tumors of the crus cerebri or of the lower part of the pons, and paraplegia, or perhaps what might be better called double hemiplegia, from multiple tumors which affect both sides of the brain. In rare cases paralysis of all four extremities has resulted from a growth in the middle line of the base of the brain. Some form of paralysis is recorded to have been present in 20 cases out of 100.
Apoplectiform attacks sometimes take place suddenly during the progress of cases of brain tumor. A patient who has been suffering for months with the general symptoms of tumor, and who may or may not have had some paresis of the limbs or face, has an attack of unconsciousness, from which he arouses after a time, and is then found to be almost completely hemiplegic. After such attacks, in some cases, the symptoms of brain-irritation, particularly the headache and vomiting, subside or greatly improve. Such attacks may be explained in several ways—from the occurrence of congestion with œdema, of intercurrent hemorrhage, or of softening from obliteration of blood-vessels by the advancing growth; and the temporary subsidence or more permanent disappearance of the headache and other symptoms is probably, in some cases at least, owing to the diminution of tension because of the breakdown of tissue in the neighborhood of the growth. Sometimes the seizures which occur during the progress of the case are both epileptiform and apoplectiform in character.
Sometimes in cases of intracranial tumor there are present in the cranial nerve-trunks and the muscles supplied by them the changes known as the reactions of degeneration. These changes are characteristic of the peripheral palsies, and indeed sharply distinguish them from paralyses of central origin. The exception to this rule in cases of intracranial growths is, of course, only apparent and not real, because these palsies, when caused by the pressure of a tumor on a nerve-trunk, even within the cavity of the skull, and not upon their proper centres or intracerebral tracts, are as much peripheral as though the injury was caused by compression of thesenerve-trunks outside of the skull. These reactions of degeneration are briefly as follows: The nerve-trunk gradually, sometimes rapidly, loses its response to both the galvanic and faradic currents. The muscle loses its response to faradism coincidently with the nerve-trunk, but to galvanism it is apt to exhibit first increased excitability, then gradually lessening excitability: and with this lessening response it puts on the so-called qualitative changes. These consist of the serial alterations—i.e.the negative pole, instead of exciting the more active reaction at closure, gives a less response than the positive pole at closure, and also calls forth a response at opening which may be greater than the opening contraction of the positive pole, which may be abolished. In health the positive pole causes often an active response, and the negative pole none, or almost none, at opening. Finally, occur modal alterations in the affected muscles, which consist of a slow, lazy contraction instead of a quick, lively one as in health, and a tendency in the muscle to remain contracted (tetany) while the current is passing. The many modifications—or, better, the partial exhibitions of these changes and the conditions underlying them—are to be sought in detail in special treatises. It is sufficient to say that they have been reported in a number of cases of brain tumor, and that the nerves in whose distributions they would be especially seen are the motor oculi, or third, the abducens, or sixth, and the facial, or seventh. It is doubtful if a very exact electrical examination could be made of many muscles supplied by these nerves, except in the case of the facial, and possibly the elevator of the upper eyelid. It is in the case of the seventh nerve that the recorded observations have been made. It will be noticed, by reference to the table, that the third, sixth, and seventh nerves are frequently involved in tumors of the crus and pons-medulla region, and that the paralysis is usually on the side of the lesion. These are the cases which would exhibit the reactions of degeneration. It has been said that in ordinary hemiplegia, and also in paralyses from tumors of the brain high in the motor region, the affected side exhibits simply a qualitative increase to electrical excitation; and this may be explained by the increased excitability to all stimuli of the lower or spinal-cord centres when cut off from the brain. The statement, however, which has been made, that in tumors of the cerebellum the sound side exhibits a quantitative decrease, sounds like a paradox, and requires further tests before being accepted as a fact in electro-diagnosis.
Ataxia has been observed in cases of brain tumor situated in various locations. The symptom described as ataxia, staggering, or staggering backward, is more particularly observed in cases of tumor of the cerebellum, pons, and corpora quadrigemina.
Changes in the state of the reflexes are somewhat frequent. Usually the skin and tendon reflexes will be increased on the side opposite the lesion, although some striking exceptions, probably due to the positions of the growth, occur.
Atrophy of the limbs is sometimes present, but usually in brain tumor, as the lesions are above the nutritive connection of the nerve, true atrophies do not occur.
True neuralgias are frequent, particularly in the distribution of the trigeminal. Trigeminal neuritis also undoubtedly occurs in lesionsinvolving this nerve at its origin, in its course, or in the Gasserian ganglion.
Anæsthesia, either in the form of local or hemianæsthesia, was observed in about 20 per cent. of the cases. It is rarely present as an isolated symptom, but frequently accompanies unilateral paresis. In a partial or variable form it most frequently is seen in connection with tumors of the Rolandic region. It is a marked symptom in postero-parietal growths and those involving the posterior part of the internal capsule. It may take the form of loss of sensation to pain, touch, pressure, temperature, etc.
Hyperæsthesia occurs so commonly as to be almost regarded as a general symptom of brain tumor. Sometimes it is confined to the head; sometimes it is generally diffused; more frequently it is present in the limb or limbs affected with the paralysis. With hyperæsthesia the patients often complain of spontaneous pain in the limbs.
Diplopia or double vision is a somewhat frequent symptom, occurring most commonly, of course, when the ocular nerves are involved directly or indirectly by the tumor; hence tumors of the floor of the skull, of the crus cerebri, of the pons, or of the cerebellum are most likely to give rise to this symptom. A close study of the character of diplopia and of other symptoms which go with it will usually enable a local diagnosis to be made. Diplopia, however, does sometimes occur in tumors situated remotely from the base, either because of pressure, because of general nervous weakness, or possibly because of involvement of cortical oculo-motor centres.
Ptosis is another symptom, generally unilateral, and most frequently present in connection with strabismus, diplopia, and dilatation of the pupil from involvement of the third nerve. Dilatation of the pupil and contraction of the pupil may be present as general symptoms of tumors. The latter is most probably due to meningeal irritation.
Hemianopsia is another ocular symptom sometimes present in cases of brain tumor, as it may also be in other forms of encephalic lesion. It was present in 5 of 100 cases. Norris25gives a full description, brought well up to the present time, of this symptom, and a discussion of the lesions upon which it depends. Seguin26also discusses this subject. Starr27has collected a large number of cases of lesion causing this symptom, some of which have been reproduced in our table. We will not go into any details as to the character of this symptom, referring the reader to the sources indicated. In the first case given in our table (Case 10) the hemianopsia was produced by a tumor in front of, and impinging upon, the optic chiasm; in the other four cases (Cases 40, 41, 42, and 43) the tumor was situated in the occipital lobe, and was surrounded by an area of destroyed tissue. Hemianopsia is not, strictly speaking, a symptom of brain tumor, but is likely to be present in cases occurring in certain regions of the brain. Starr's conclusions with reference to lateral homonymous hemianopsia when it is not produced by a lesion of one optic tract are that it may result from a lesion situated either (1) in the pulvinar of one optic thalamus; (2) in the posterior part of one interior capsule or its radiation backward toward the occipital lobe; (3) in the medullary portion of the occipital lobe; or(4) in the cortex of one occipital lobe. The conclusions of Seguin are only different in so far as they more closely limit the position of the lesion.
25Vol. IV.
26Pp. 84, 85 of present Volume.
27Amer. Journ. Med. Sci., N. S., vol. lxxxvii., January, 1884, p. 65.
Phosphenes, or subjective sensations of light, occur in various forms—simply flashes or sheets of light, scintillations, balls of fire, etc. They are not very common as isolated phenomena, and probably are dependent in most cases upon irritation of the nerve and retina in some of the stages of neuro-retinitis. Even visual hallucinations are occasionally present, as in one of Bennett's cases of tumor of the Rolandic region.
Conjugate deviation of the eyes, with rotation of the head, a symptom of the early stages of apoplectic attacks, is also sometimes observed in brain tumor. The patient is found with both eyes turned to one side and slightly upward, as if looking over one or the other shoulder, the head and neck being usually rotated in the same direction. Sometimes the deviation is slight, sometimes it is marked. Frequently the muscles of the neck on one side are rigid. The eyes are commonly motionless, but occasionally exhibit oscillations. This sign, well known to neurologists, usually disappears in cases of apoplexy in a few hours or days, although it occasionally persists for a long time. It will be more fully considered under Local Diagnosis.
Diminution or loss of hearing, tinnitus, and hyperæsthesia of hearing are all occasionally observed. The most decided disturbances of this sense are those which are found in connection with tumors of the base or of the cerebellum in such a position as to involve the auditory nerve or auditory tracts. Tinnitus, acoustic hyperæsthesia, with complete or partial deafness, accompanying facial paralysis, with or without paresis of the limbs of the opposite side, indicate clearly a tumor of the base so situated as to involve the superficial origin or intracranial course of the auditory and facial nerves.
The sense of smell is affected, of course, when the olfactory bulbs are involved in the growth, either directly or by pressure, as in certain tumors of the antero-frontal region (Cases 4 and 8). Disturbances in the power of consciously perceiving odors, or abnormal perceptions of odors or hallucinations of smell, are sometimes present in cerebral tumors involving certain convolutions. The lower postero-parietal region or the temporo-sphenoidal region of the base would seem, from the few reported cases, to be implicated when this sense is centrally affected. Smell was lost or impaired in two cases of tumors of the postero-parietal region, in one limited to the supramarginal convolutions. In a case reported by Allan McLane Hamilton (Case 47), an induration of the lower part of the right temporo-sphenoidal lobe involving the uncinate gyrus, the patient, preceding light epileptic attacks, always had an olfactory aura of a peculiar character—a disagreeable odor, sometimes of smoke and sometimes of a fetid character. In this case the olfactory nerves were examined and found to be healthy.
Taste may be involved in several ways. In the first place, subjective sensations of taste, particularly the so-called metallic taste, may be present when the growths involve the cranial nerves in such a way as to cause irritation to be conveyed to the nucleus of the hypoglossal. When it is remembered that a mild galvanic current applied to the nape of the neck or face will often cause this metallic taste, it can be seenthat the irritation of a tumor situated at almost any point of the base might lead to abnormal taste-phenomena. Neoplasms involving the trunk of the portio dura may of course cause diminution or loss of taste on the anterior extremity of the tongue by the involvement of the chorda tympani nerve. In the very few cases in which the hypoglossal trunk may be involved disturbances of taste posteriorly may occur. In two cases (Cases 33 and 36) some possible indications as to the cortical areas of taste are given. One was a tumor so situated as to cause pressure on the orbital, and possibly anterior, portion of the temporo-sphenoidal lobe; the other was a lesion closely localized to the supramarginal lobule.
Trophic disturbances of decided character are sometimes present in cases of brain tumor. Their presence, character, and extent depend upon the position of the tumor and the cranial nerves involved. Trophic disorders of the eye have been noted in cases of tumor of the antero-frontal region, and also of various positions at the base, especially those so situated as to involve the trigeminal nerve. In a fibroma of the superior antero-frontal region (Case 1) conjunctivitis and corneitis of the left eye, with anæsthesia of the conjunctiva, were present, and were very marked symptoms. This patient, who was under the care of one of us at the Philadelphia Hospital, was examined by O. E. Shakespeare, ophthalmologist to the hospital. At his first examination the bulbar conjunctivæ were slightly injected and the cornea clear. The sensibility of the cornea was possibly a little lowered. Ten days later, at a second examination, the central corneal epithelium of the left eye was found to be hazy and the whole bulbar conjuntivæ much congested. “This condition soon developed into a severe superficial corneitis, which was mainly limited to a central area of an extent about equal to three-fourths of the diameter of the cornea, which threatened to slough, a narrow peripheral ring of the cornea being comparative unaffected. At the same time the engorgement of the bulbar conjunctiva increased. The sclera, the iris, and the deeper parts were apparently not involved in the inflammatory process.â€
Disturbances of respiration were observed in a number of cases in various stages. Cheyne-Stokes breathing was usually a late symptom. In a case of tubercular meningitis with a tubercular granulation springing from the left side of the fourth ventricle (Case 82) it was present. Extraordinary slowing of respiration occurred in a tumor of the right middle cerebellar peduncle and cerebellar hemisphere which caused irritation and softening of the floor of the fourth ventricle. The respirations ran as low as four and five per minute two weeks before death.
Persistent epistaxis and a tendency to hemorrhage from the mucous membranes were interesting vaso-motor phenomena in a case situated in the upper left quarter of the pons (Case 84). Profuse perspiration, more marked on one side, was observed in a case of tumor in front of the optic chiasm. Polyphagia was observed in two cases, one a growth of the cerebellum and the other on the floor of the skull. Polyuria was a very marked symptom in Case 95, a tumor at the base of the brain at a spot corresponding to the sella turcica, and diabetes was present in a case of frontal tumor. Albuminuria was recorded twice—once in the same case in which diabetes was present, and again in a case ofmultiple tumor of the supramarginal convolution of one side and the angular gyrus of the other. Somnolence was occasionally observed.
Constipation or torpor of the bowels occurs somewhat frequently in the early stages of the brain tumor, giving place in the terminal periods to involuntary evacuations. The conditions of the bladder are practically the same. It is either not involved or suffers from torpor or paresis of the muscular walls early in the disorder, and later, and especially very late, incontinence from paralysis of the sphincter results.
DURATION, COURSE,ANDTERMINATION.—The duration of cases of intracranial tumor is very uncertain. In many of the reported cases no definite information is given as to the exact length of time from the initial symptoms until the fatal termination. The few cases in which the time was recorded showed a duration of from three months to as many years.
In a few cases, even in some which are not syphilitic in character, a remission of all the symptoms and what appears to be an approximate cure sometimes take place, the general symptoms, such as headache, vertigo, vomiting, spasms, etc., disappearing for a time. Even the condition of the eyes and the paralysis in rare instances make marked improvement. In these cases, in all probability, the progress of the growth of the tumor is arrested either by the remedies employed or spontaneously, and the acute or subacute phenomena of congestion, Å“dema, etc. around the tumor subside. These patients may remain for a long period or until cut off by some other disease without any change for the worse; but the sword constantly hangs above their heads, and any excitement, traumatism, the abuse of alcohol or other narcotics, an attack of fever, or some other special exciting cause, may again light up the intracranial disorder, to then progress more or less rapidly to a fatal termination.
This fatal termination may occur in various ways. Sometimes a sudden apoplectic attack occurs. This may be an intercurrent hemorrhagic apoplexy, although our personal experience would not lead us to believe this mode of termination is common. In a few cases the enormous irritation of the cerebral growth suddenly or gradually inhibits the heart's action through the impression made on the pneumogastric. Apoplectic attacks which may or may not terminate fatally sometimes are the result of a sudden giving way of necrosed brain-tissue, the necrosis having resulted from the obliteration of numerous blood-vessels by the advancing growth. Blood-poisoning occasionally takes place from abscesses in proximity to the tumor. In some cases the patients slowly but surely emaciate, or are exhausted and worn out by the agonizing pain and incessant vomiting which they are called upon to endure. Occasionally a more or less diffused and violent meningitis hastens the fatal issue.
COMPLICATIONS ANDSEQUELÆ.—Tumors of the brain may be complicated with other affections due to the same cause. Thus, for example, in a case of gumma other evidences of syphilis may be present in the form of nodes, eruptions, etc. A sarcoma or carcinoma of the brain may be associated with similar disease in other organs. Such affections as cystitis, pyelitis, keratitis, etc., which have been discussed under Symptomatology, are secondary complications of cases of tumor. Asintracranial tumors almost invariably terminate fatally, strictly speaking we have no sequelæ.
PATHOLOGY.—We present in tabular form the various classes of tumors found in the one hundred cases of brain tumor in the table appended to this article:
The histology of tumors of the brain does not in the main differ from that of the same growths as found in other parts of the body, so that a detailed description of their structures, even though founded upon original research, could not offer many novel facts in a field which has been so thoroughly cultivated. Such a description would probably repeat facts which have already been presented in other parts of this work, and which are better and more appropriately put forth in special treatises devoted to the science of pathology. It is proper, however, for the sake of convenience and thoroughness, to make brief mention of the structure of brain tumors, and especially to dwell upon certain features of these morbid growths which may be considered characteristic of their encephalic location, and hence have not only pathological but also clinical interest. It is hardly worth while to refer to speculations which aim to elucidate the very foundations of the science, except that in a few of these theories we gain an additional insight into both the structure and conduct of some very characteristic brain tumors.
Cohnheim's theory was that tumors are formed from foci of embryonal tissue which had been non-utilized or left over in the intra-uterine development of the body. Many have not accepted this idea, but have rather considered that in tumors we witness a reversion of tissue to lower or embryonic types.28Whether we accept either or neither of these propositions, the idea sought to be conveyed is that in all these morbid structures we have a tissue of low or degraded character, springing in most instances from a connective or non-differentiated tissue. This fact is brought out very clearly in many of these intracranial growths. Virchow29has said that tumors originate in the cells of the connective tissue, although his law has been condemned as not of sufficient breadth, since it seems to ignore the epithelial and myomatous tumors. Dermoid cysts, of which an example is given in the table of spinal tumors,30are said to illustrate the embryonic function revived—i.e.the tendency of lower tissues to spontaneously differentiate into higher and more complex ones.
28Article “Pathology†inBrit. Encyc., by C. Creighton.
29Quoted by Cornil and Ranvier.
30Page 1107.
The gliomata are among the most common and characteristic tumors of the cerebro-spinal axis, to which system and its prolongation into the retina they are confined. They invariably spring from the neuroglia or connective tissue of the nerve-centres, and reproduce this tissue in an embryonal state. They greatly resemble the brain-substance to naked-eye inspection, but have, histologically, several varieties of structure.These variations depend upon the relations of the cell-elements to the fibres or felted matrix of the neoplasm. In the hard variety the well-packed fibrous tissue preponderates over the cell-elements, and we have a tumor resembling not a little the fibromata (Obernier). The second variety, or soft gliomata, show a marked increase of cells of varied shapes and sizes, with a rich vascular supply which allies these growths to the sarcomata. The elements of gliomata sometimes assume a mucoid character, which allies them, again, to the myxomata.
FIG. 43.
Glioma cell
Flat Glioma-cell with its Fibrillar Connections (Osler).
FIG. 44.
Fibre cell
(1) Homogeneous translucent fibre-cell; (2) cells like unipolar ganglion-cells; (3) giant cell (Osler).
W. Osler has recently described31to the Philadelphia Neurological Society the structure of certain of these tumors, from which we abstract the following facts: One point referred to is that gliomata sometimes contain larger cells and coarser fibres than are usually shown. The structures are (1) The “spinnen†or spider-cells (characteristic of glioma), which present variations in size; (2) large spindle-shaped cells with single large nuclei (some of the largest cells met with in tumors); (3) cells like the ganglion-cells of nerve-centres, with large nuclei and one or more processes: some are balloon-shaped with single processes; they are larger than the spider-cells; (4) translucent band-like fibres, tapering at each end, without nucleus or granular protoplasm, regarded as a vitreous or hyaline transformation of the large spindle-cells. Klebs (quoted by Osler) holds that the ganglion-like cells are derived from the nerve-cells of the gray matter, “and that in the development of this variety all elements of the nerve-tissue participate.†Osler examined the advancing region ofthe tumor, and was not able to satisfy himself that the nerve-cells were in process of proliferation. He thinks they are connective-tissue elements. He has seen but two out of five cerebral gliomata which were of small-celled type.
31“Structure of Certain Gliomas,â€Philada. Med. News, Feb. 20, 1886.
The gliomata are subject to fatty degeneration, which usually occurs in the central (older) portions of the mass. The more vascular forms are also peculiarly liable to hemorrhage, which is probably caused in some instances by this process of retrograde metamorphosis. These hemorrhages resemble apoplexies, not only in their clinical features, but also on gross examination. Great care is therefore often necessary at the autopsy to distinguish such a hemorrhage, occurring as it does in a brain-like neoplasm, from one caused by the rupture of a diseased artery. The hypertrophy of the pineal gland, sometimes noted, is caused by the formation of gliomatous tissue. Under the microscope it is necessary carefully to distinguish some forms of inflammatory new formations from the gliomata. We have recently seen, by the courtesy of E. N. Brush of the Pennsylvania Hospital for the Insane, photographs of microscopic sections from the ependyma of the lateral ventricles in a case of general paresis, which showed the structure of this degenerated tissue to be a compound of fibres and cells of marked resemblance to gliomatous tissue.32
32These micro-photographs were prepared in the laboratory of the State Lunatic Asylum, Utica, New York, by Theodore Deecke.
Sarcomata of the brain are common, as our table shows. In them the cell-elements predominate, both in the large- and small-celled variety. They are malignant and grow rapidly. The form known as alveolar sarcoma, which has a distinct stroma, is to be distinguished from the cancers; which has probably not always been done.
Tubercle, according to Ross, is the most common of all forms of brain tumor. Our table shows 13 cases out of 100, the gliomata and sarcomata being in larger number. Its favorite seat is in the cortex of both the cerebrum and cerebellum: some observations appear to show that it is more common in the cerebellum and mid-brain region than in the fore-brain, and in children than in adults; some of which points distinguish it from the gummata, which are more common in adults and occur anywhere. Tubercle is another form of development from the connective tissues, usually dependent upon a constitutional taint or predisposition: in it the cell-elements have generally undergone a degeneration into an amorphous cheesy mass. It is apt to be multiple and accompanied by a similar deposit in other organs of the body.
True neuromata are probably very rare growths, and it is likely that some tumors which have been described as such are really connective-tissue tumors of a gliomatous nature, in which some of the cell-elements have been mistaken for the ganglion-cells. Obernier33says that these tumors are small and grow from the gray matter on the surface, also on the ventricular surfaces. They are also found in the white matter. He says they are only found in persons having some congenital or acquired aberration; by which is probably meant some other well-marked neurosis or psychosis. The one hundred tabulated cases afforded no examples of neuromata.
33Op. cit.
Myxomata are not, histologically, to be distinguished from thegliomatous tissues by anything but the peculiar mucoid changes which their structures have undergone. They are more rare in the brain, as our tables show, than in the spinal cord.
Lipomata are very rare in the brain, according to most observers. The table shows but one example. These tumors, as their name signifies, are made of fat-bearing tissues—another of the connective-tissue class.
The angiomata, somewhat rarely found within the skull, are noted for their abnormal development of the vascular tissues: they are composed mainly of blood-vessels and the connective tissue, which supports them in closely-packed masses. They also present cavernous enlargements. They are of especial interest in cerebral pathology, because the lesion known as pachymeningitis hæmorrhagica, often found in dementia paralytica, is considered by some to be angiomatous; although by far the most generally accepted view of this latter condition is that it is due to arterial degeneration, and in part is an inflammatory exudate.
Syphilitic tumors, or gummata, are, like tubercle, a special development with degeneration from the connective tissue, due to a constitutional taint. This new growth is sometimes single, sometimes multiple. The corpuscles of the neuroglia are the apparent points of origin of the tumor, the substance of which is the firm, peculiarly gummy, and non-juicy material from which the name is derived. It would be impossible in our allowed space to trace this neoplasm through the successive stages of its development. It has especial clinical interest, inasmuch as it and its damage are probably amenable to specific treatment when it has not progressed to too great a destruction of brain-tissue.
The true cancers, or epithelial neoplasms, are not a common form of tumor of either the brain or spinal cord. They present, as in other parts of the body, a stroma forming alveolar spaces in which are contained the nests of epithelial cells. These tumors thus present characteristic differences in their histology from the connective-tissue or mesoblastic groups, but clinically no very special interest attaches to them. Their location, the rapidity of their growth, and their fatal import are points which they share with most other new growths of the cranial cavity.
The cholesteotomata, or pearl cancers, consist of hardened epithelial cells which have undergone a sort of fatty degeneration.
The psammomata are loosely described as tumors containing sand-like bodies, which bodies are normal about the pineal gland. These sand-like bodies are found in tumors of some histological diversity, and do not appear to have much identity of their own. They occur in sarcomata and carcinomata, and are probably not to be distinguished from mere calcareous infiltration and degeneration. They are most common in sarcomata, as this is one of the most common of cerebral tumors.
True osteomata—i.e.tumors with the structure of true bone—are probably rare in the brain, although more common on the inner table of the cranium; but the deposition of calcareous salts has been recorded in a variety of conditions. F. X. Dercum, in a recent paper read before the Philadelphia Pathological Society,34has recorded the autopsy of a paretic dement in which case calcareous deposits were scattered throughout both hemispheres and the cerebellum. He believes that “the areas inwhich the concretions were found were probably foci of encephalitis of greater intensity than elsewhere. In these foci inflammatory changes in the walls of the vessels became pronounced; besides which the vessels increased enormously in size and number; so marked is this increase that these foci could, with perfect propriety, be called angiomata.†This is followed by proliferation of the neuroglia, compression and destruction of nerve-tissue, and deposit of the calcareous salts especially about and upon the coats of the vessels. This case illustrates in the simplest manner the formation of both vascular and sand tumors.
34The Medical News, April 24, 1886, p. 460.
Pacchionian bodies are very common in the brain, and are really small fibromata. They may form true tumors (Cornil and Ranvier) capable of wearing away the bones of the cranium. In fact, even when small they may have corresponding indentations in the skull. They are not to be mistaken for tubercle. Clouston35has described excrescences from the white matter of the brain, growing through the convolutions, projecting through the dura mater, and indenting the inner table of the skull; which new growths he calls hernia of the brain through the dura. We have not seen such a condition described elsewhere, and think that we have here probably Pacchionian bodies growing from the pia mater. They were found in a case of tumor of the cerebellum.
35Journ. Ment. Sci., xviii. p. 153.
A cystic formation, constituting a veritable tumor, not unfrequently occurs in the pituitary body and mounts into the third and lateral ventricles. Echinococci and hydatids also occur, and have the same natural history as these parasitic offspring have when found in other parts of the human body.
Obernier refers to an enchondrosis of the basilar process. Our table presents one case of enchondroma.
Some of the gross appearances found on autopsies of tumors of the brain are worthy of note. Often an area of congestion or inflammation, especially of the membranes, is seen about the new growth, and the brain-substance in its immediate vicinity is much more frequently softened. The cerebro-spinal fluid is increased, and, especially when direct pressure has been exerted upon the veins of Galen, are found distended lateral ventricles. When a tumor does not approach the surface, but has attained some size, the hemisphere in which it is located often has a bulging appearance, crowding over upon its neighbor, and the convolutions are flattened by the pressure. The cranial nerve-trunks are occasionally involved in or stretched by the tumor, and also occasionally the bones of the vault or base of the cranium are extensively eroded. This happens especially in cancer and osteo-sarcoma.
A few remarks should be made about the methods of making post-mortem examinations and the gross appearances and conditions likely to be found in brain-tumor cases. As not a few intracranial tumors are connected with the bone or with the dura mater, the latter being adherent to the skull-cap in some positions because of inflammation arising from the seat of the growth, especial care should be taken in removing the calvarium. Examination of the external surface of the dura mater will sometimes reveal the presence of a growth beneath or incorporated with this membrane. The dura mater should not be roughly dragged from the surface of the brain, but should be carefully removed by aprocess of partial dissection. During this process a meningeal growth will sometimes be found growing apparently from the fused membrane. In such cases it is usually better to so proceed as not to entirely separate the outer membrane from the growth. Indeed, this cannot be done sometimes without injury directly to the specimen, and especially to its cerebral surroundings. The dura mater having been removed, a marked opacity, sometimes a dirty-brown hue shading off into a lighter color, will indicate to the eye the probable presence of a tumor beneath and growing from the pia mater of the cortex. In such a case, and even when no such appearance is present, but a tumor is suspected, the fingers passed carefully over the cerebral surface will feel a hard, and it may be nodulated, mass at some position. A growth, having been located in this way, should not be roughly handled or at once examined by section. An effort should be made to accurately localize it, not only with reference to lobes, but also with reference to convolutions and fissures, and even special portions of these. This is best done, after a thorough examination has been made of the pia mater, by carefully stripping the pia mater from the brain, beginning at points some distance from the growth and gradually approaching it, and leaving the pia mater for a short distance around the growth connected with it. The location having been fixed and other portions of the brain having been examined, if it is not possible or desirable to retain the entire brain as a specimen, a block should be removed embracing a considerable portion of healthy brain-tissue on all sides of the tumor. In order to study the gross internal appearance of the tumor, it is a good plan to make a clean section through the middle of the tumor. From each side of this cut fragments can be taken for microscopical examination without deranging appreciably the size and appearance of the tumor.
When the tumor is not meningeal or cortical, or not situated at the base or floor of the skull, its presence may be revealed, when it is in centrum ovale and of considerable size, by either hardness or fluctuation of the hemisphere in which it is located, this fluctuation not being due to the tumor itself so much as to the breakdown of tissue around it. Large sections in known positions with reference to convolutions and ganglia should be made when examined for tumors deeply situated. If possible, sections close to and just before and behind the growth should be made, so as to assist in the accurate localization.
Small tumors are not infrequently overlooked by careless observers, and even growths of considerable size have escaped discovery by one examiner to be found by another. Tumors in certain special localities, as between the temporo-occipital lobe and the superior surface of the cerebellum in the great longitudinal fissure, or small growths in the substance of the cerebellum or deep in the Sylvian fissure, are more likely than others to be passed by, although this, of course, is not likely to occur when the examination is made by a competent or careful physician.
DIAGNOSIS.—The diagnosis of the existence of an intracranial tumor, as a rule, is not difficult. It can be made with greater certainty than that of almost any other serious encephalic disease.
It is sometimes important to decide as to the nature of an intracranial neoplasm, particularly whether or not it is syphilitic. Little is to be gained by following the plan adopted by some physicians, of treating all cases as if they were due to syphilis, on the principle that theseare the only forms of tumor which can be reached by treatment. The pitiable condition of such patients is sometimes thus made worse. In every case careful and persistent efforts should be made to obtain an authentic previous history from the patient. Whenever possible the physician should search directly for the physical evidences of the former existence of syphilis—for cicatrices on the genitals and elsewhere, for nodes and depressions, for post-cervical and other swellings, etc. A history of previous disease of the throat and of pains in bones and nerves, of epileptiform attacks, of headache, and eye symptoms which have disappeared under treatment, should be sought out. It is not well to give too much credence to the stories of patients, who are not always willing to admit their past lapses from virtue; but, on the other hand, the plan of suspecting everybody who presents advanced cerebral symptoms is often a grievous wrong. Not infrequently external cranial nodes are present in cases of intracranial syphilis.
Carcinomata and sarcomata, particularly the former, are comparatively rapid in their progress. They sometimes involve the bones of the skull, even to the extent of perforation.
The existence of an inherited tendency and of tuberculosis in other organs, with the special phenomena of general tuberculosis, assists in the diagnosis of tubercular tumors.
The frequent occurrence of gliomata in early life, and the comparatively frequent absence of severe irritative symptoms, with the well-preserved general nutrition of the patient, speak for these growths.
Cerebral abscess is, on the whole, more difficult to diagnosticate from intracranial tumor than any other affection. Abscess, however, more frequently than tumor, can be traced directly to a traumatism. It is often associated with disease of the internal ear. Obernier speaks of the headache of cerebral abscess as slight, but this does not correspond with usual experience. Headache, on the whole, may be oftener absent or less agonizing in abscess than in tumor, but it is frequently present, and sometimes of great severity. Its greater mildness in a few cases is to be explained by the fact that abscess does not produce so much pressure within the intracranial cavity, and does not so frequently cause irritation of the branches of the trigeminus in the dura. Undoubtedly, the symptoms of abscess often remain for a long time comparatively latent, with then a sudden outburst of violent symptoms. The course of brain tumor is more uniformly and steadily progressive, and febrile phenomena, the results of pyæmia, are of more frequent occurrence in abscess than in tumor.
In old cases of tumor it is sometimes necessary to differentiate between it and the results of various forms of apoplexy, such as hemorrhage, thrombosis, and embolism. Cerebral hemorrhage, embolism, or thrombosis leaves a condition of paralysis, sometimes with, but usually without, accompanying spasm or convulsion, which simulates closely the paralysis and other permanent conditions of cases of tumor occurring in the same cerebral locality. In these cases, in the first place, the history of the disease will throw considerable light upon the diagnosis. In both hemorrhage and embolism the history is usually one of a sudden attack without special premonitory symptoms. Hemorrhage gives usually a precedent history of diseased kidneys, hypertrophied heart, oratheromatous blood-vessels, and occurs generally in advanced life; embolism, a history of rheumatism and valvular disease of the heart, occurring at any period of life, early or late. In brain tumor the previous history is usually one of traumatism, of constitutional infection, or of a special predisposing diathesis. Blows and falls upon the head are common antecedents, or a history of syphilis, tuberculosis, scrofula, or cancer is present. Tumor, like embolism and unlike hemorrhage, may occur at any time of life. While slight or dull headache, with more or less vertigo, may be present in cases of hemorrhage and thrombosis, the severe and often agonizing headache, with vomiting and serious vertiginous attacks, which precedes the paralytic or other phenomena of tumor, is a much more conclusive symptom in the latter cases than in the former. Choked discs and optic neuritis are much more likely to occur in tumor than in the other affections.
Brain tumor must sometimes be diagnosticated from the head symptoms of some form of Bright's disease. A case not long since presented itself to one of us with a history of having suffered at frequent intervals for two years with headache of gradually increasing severity. Dimness of vision and slight temporary Å“dema of the feet, circumscribed and painful swellings along the lymphatics of the thighs and legs, with some mental irritability, were other marked symptoms. The patient had been attended by several physicians of prominence, one of whom had diagnosticated tumor of the brain. The violent, apparently agonizing headache, with the diminution of vision, and the absence of marked symptoms indicating other organic disease, made the diagnosis of a growth in some non-excitable region of the cerebrum most probable. Examination of the urine showed no albumen. Careful examination of the eye-ground with the ophthalmoscope, however, revealed the appearances of retinitis albuminurica. Under a treatment directed to the relief of chronic nephritis the patient's headache and other symptoms improved.
It must not be forgotten just here, however, that, on the one hand, ophthalmoscopic appearances very similar to those of albuminuric retinitis are sometimes present in rare cases of brain tumor, and also in other constitutional disorders, such as leukæmia; and, on the other hand, that, as stated by Norris,36exceptional forms of albuminuric retinitis have been reported where the only change seen in the fundus oculi was pronounced choking of the disc.
36Op. cit.
Intracranial tumors must be diagnosticated from meningitis in its various forms. In children tubercular meningitis sometimes closely simulates brain tumor. Tumors of the brain are comparatively rare in children, but, as has already been shown, gliomata and other tumors do sometimes occur in early life. The course of tubercular meningitis, whether in children or in adults, differs from that of brain tumor. It is more irregular in its method of advance, or if it shows the regularity which is sometimes present, and which has led authors to subdivide it into three more or less completely separable stages, the symptoms of these stages do not correspond with any closeness to those of the initial, middle, and terminal periods of brain tumor, as already given. Headache is usually present in both affections, although the absence of headache in some cases of gliomata in children must be here borne inmind. When headache is present in tubercular meningitis, it is less likely to be localized, and, on the whole, it is not so severe as the terrible torture of the neoplasm. Irregular but very decided febrile phenomena are more likely to be present in meningitis than in tumor. Like brain tumor, tubercular meningitis of the convexity may give psychical disturbances, palsies, local spasms, general convulsions, sensory disturbances, peculiar disorders of the special senses, etc.; but these symptoms in the former usually come on more irregularly and are accompanied less frequently with paroxysmal exacerbations of headache, vomiting, vertigo, etc. Tubercular meningitis of the base can be more readily distinguished from cases of tumor by the fact that one cranial nerve after another is likely to become involved in the diffusing inflammatory process. Tubercular meningitis is of shorter duration than the majority of cases of brain tumor, and in it delirium and mental confusion come on more frequently and earlier. A history and physical evidences of more or less generalized tuberculosis favor the diagnosis of tubercular meningitis. In both affections the ophthalmoscope may reveal choked disc or descending neuritis. It will be seen that the differentiation between the affections is not always very clear, although in some cases the decision may be quickly reached from a study of the points here suggested.
Some of the forms of chronic hydrocephalus are difficult to distinguish from tumors, especially gliomata. In hydrocephalus, when not the result of, or not accompanied by, tubercular meningitis, the disease advances more slowly and with less irritative symptoms than in cases of tumor. Headache, vertigo, vomiting, and the other symptoms of meningeal irritation are not so frequently present, although the ophthalmoscopic appearances are often the same.
Rosenthal speaks of the necessity of diagnosticating brain tumor from the chronic cerebral softening of Durand-Fardel, from acquired cerebral atrophy, and the cerebral hypertrophy of children. An elementary knowledge of the general symptomatology of intracranial tumors will, however, be sufficient to prevent mistakes of differentiation in these cases. Neither of these affections presents the violent paroxysmal symptoms, the affections of the special senses, or the severe motor and sensory phenomena of intracranial growths.
Acute mania and paretic dementia are sometimes confounded with intracranial growths. A case of brain tumor is more likely to be regarded as one of acute mania than the reverse. In some comparatively rare instances in the course of their sufferings the cases of tumor become maniacal, but even a superficial study of general symptomatology in such a case will be sufficient to clear up the doubt.
Paretic dements are occasionally supposed to be cases of brain tumor, because of the epileptiform attacks and isolated pareses which occur as the disorder progresses. It is only necessary to refer to this matter, as the mistake would not be likely to be made by one having any familiarity with dementia paralytica.
L. J. Lautenbach, in a recent communication to the Philadelphia Neurological Society, which embodied a large number of ophthalmoscopic examinations of the insane at the State Insane Hospital, Norristown, Pennsylvania, and the Insane Department of the Philadelphia Hospital, and also the results of the investigations of the fundus of the eye incases of insanity by other observers, showed that about 16 per cent. of cases of acute mania presented well-defined papillitis—a condition which he described as one of swelling and suffusion of the disc, corresponding to cases reported as choked disc, descending neuritis, and severe congestion of the optic nerve. No reports of post-mortem examinations were made of these cases, but they did not present the clinical history of meningitis or brain tumor. It therefore follows that the existence of papillitis in a case of acute mania does not necessarily point to a gross lesion, such as tumor or meningitis.
In the early stage of posterior spinal sclerosis some of the symptoms of the initial or middle stage of intracranial growths in certain positions are likely to be present; more particularly, such eye symptoms as diplopia from deficiency or paresis of the ocular muscles and disorders of the bladder may mislead. In posterior spinal sclerosis, however, some at least of the pathognomonic symptoms of locomotor ataxia, such as lancinating pains, absent knee-jerk, or Argyle-Robertson pupil, will almost invariably be present. Those tumors of the cerebellum, pons, tubercular quadrigemina, etc. which give rise to ataxic manifestations are usually readily discriminated from posterior spinal sclerosis by the headache, vomiting, and other general symptoms of brain tumor, which rarely occur in ataxia. It is far more difficult to separate non-irritative lesions of certain cerebellar and adjoining regions from the spinal disorder.
Strange to say, one of the most frequent mistakes of diagnosis is that which arises from confounding brain tumor with grave hysteria. In several of our tabulated cases the patients at different periods of the disease and by various physicians had been set down as suffering from hysteria. One of Hughes-Bennett's cases (Case 30), a wayward, hysterical girl of neurotic family, had had her case diagnosticated as hysteria by one of the highest medical authorities of Europe, and yet after death a tumor the size of a hen's egg was found in the cerebrum. In a case reported by Eskridge (Case 76) hysterical excitement and special hysterical manifestations were of frequent occurrence, and misled her physicians for a time. Eskridge remarks, in the detailed report of this case, that to such a degree was the emotional faculty manifest that had no ocular lesion been present there would have been great danger of mistaking the case for one of pure hysteria; and, indeed, a careful physician of many years' experience, not knowing the condition of the eyes, pronounced the woman's condition to be pregnancy complicated by hysteria. A close study of such objective phenomena as choked discs and paralysis will usually be of the most value.
Even malaria has been confounded in diagnosis with brain tumor. Holt37reports a case which presented the history of a fever, at first periodical, with marked splenic enlargement, great muscular soreness, and incomplete paralysis, which was diagnosticated to be chronic malarial poison. The patient for a time improved under quinine, but eventually grew worse, and on an autopsy a glioma-sarcoma was found on the inferior surface of the cerebellum. Several years since a physician about fifty years of age was brought to one of us for consultation, and in his case a similar mistake had been made. The case was a clear one oftumor, probably cerebellar, with headache, neuritis, vertigo, and other general symptoms, which pointed to an organic lesion. This patient, who came from a malarial district in the West, had doctored himself, and had been treated by others with enormous doses of quinine and arsenic.
37Med. Record, March 1, 1883.
LOCALDIAGNOSIS.—Niemeyer would hardly say to-day that the brilliant diagnoses where the precise location of a tumor is fully confirmed by autopsy are not usually due to the acumen of the observer, but are cases of lucky diagnosis. It can be asserted with confidence that the exact situation of a tumor can be indicated during life in at least two or three locations. Great caution should be exercised, as insisted upon by Nothnagel,38in the localization of tumors of the brain, because, among other reasons, of the frequent polypus-like extension of such tumors.
38Wien. Med. Bl., 1, 1882.
The subject of local diagnosis can be approached in several ways, according to the method of subdividing the brain into regions. Thus, Rosenthal discusses, in the first place, tumors of the convexity of the brain, but as this is a very general term, covering portions of several lobes, we can see no advantage in making such a subdivision.
A few general remarks might be made in the first place, however, with regard to the general symptoms presented by surface or cortical growths as compared with those which are produced by deep-seated neoplasms. The direct or indirect involvement of the membranes in nearly all cortical tumors makes the symptoms of irritation referable to these envelopes very numerous and important.
The various centres so called, motor, sensory, and of the special senses, which have their highest differentiation in the cerebral cortex, are each and all represented by well-defined tracts of white matter in the centrum ovale and capsules which connect these centres with the lower brain, the spinal cord, and the periphery of the organism. It therefore follows that symptoms produced by localized lesions of the cortex will be reproduced in other cases by those of the tracts which go to or come from these centres. We may thus have a monoplegia or a hemiplegia, a partial anæsthesia or a hemianæsthesia, a hemianopsia, a word-blindness or word-deafness, a loss of power to perceive odors or to appreciate gustatory sensations, from a peculiarly limited tumor or other lesions of either the gray centres of the cortex or of the white matter of the central area of the brain; but these specialized symptoms are more likely to arise from cortical lesions in the case of intracranial neoplasms, because of the much greater frequency with which these adventitious products arise from membranes and therefore involve the cortex.
Peculiar symptoms arise in the case of lesions of the centrum ovale from the fact that it contains not only projection-fibres which more or less directly connect cerebral centres with the outer world; but also a system of commissural fibres which unite corresponding regions of the two cerebral hemispheres by way of the corpus callosum and commissures, and a system of association-fibres which connect different convolutions together, in special cases even those which are situated remotely from each other, but are associated in function.
It is evident, therefore, as asserted by Starr,39that a peculiar set of additional symptoms will be referable to the destruction or irritation of these commissural and association fibres. For example, failure toperform easily corresponding bilateral motions in face, hands, or feet would indicate some obstruction to conduction in the commissural fibres joining the motor convolutions. “Integrity of both occipital lobes, and simultaneous, connected, and harmonious action in both, are necessary to the perfect perception of the whole of any object when the eyes are fixed upon one point of that object.†Starr gives the following examples of the methods of detecting a lesion of such fibres: “In the case of the fibres associating the auditory with the motor speech-area the symptoms to be elicited seem to be very simple. Can the patient talk correctly? Can he repeat at once a word spoken to him? These are the questions which any one will ask who examines a case of aphasia. But this is not all. The patient must be further questioned. Can he read understandingly to himself, and tell what he has read? This will test the occipito-temporal tract. Can he read aloud? This will test the occipito-temporo-frontal tract. Can he write what he sees? This will test his occipito-central tract. Can he write what he hears? This will test the temporo-central tract. Can he write what he says, speaking to himself in a whisper? This will test his fronto-central tract. Can he name an odor or a color? Brill has recorded40a case of lesion of the cuneus associated with color-blindness to green, and he states that the patient had difficulty in naming various colors on account of the presence of a slight degree of amnesic aphasia.... Can the patient write the name of an odor? Can he tell how a surface feels—smooth, or warm, or heavy? Such questions as these will suggest themselves at once to any one who studies the association of ideas subjectively.