A system of practical medicine. By American authors. Vol. 5

by Unknown

The contents of a cerebral abscess usually develop a peculiarly fetid odor. It has been claimed that this odor is particularly marked in cases where the abscess was due to some necrotic process in the neighborhood of the brain-cavity. The only special odor developed by cerebral abscesses, as a rule, is identical with that of putrid brain-substance, and it must therefore depend upon the presence of brain-detritus in the contents of the abscess or upon the rapid post-mortem decomposition of the neighboring brain-substance.

In two cases of miliary abscess which, as far as an imperfect examination showed, depended on an invasion of micro-organisms, an odor was noticed by me which was of so specific a character that on cutting open the second brain it instantly suggested that of the first case, examined six years previous, although up to that moment I had not yet determined the nature of the lesion.⁵²

⁵² Owing to the lack of proper methods of demonstrating micro-organisms, the first case whose clinical history was known was imperfectly studied; of the second case, accidentally found in a brain obtained for anatomical purposes, the examination is not yet completed.

That form of abscess which, from its situation in or immediately beneath the surface, has latterly aroused so much interest from its important relations to localizations is usually metastatic, and directly connected with disease of the overlying structures, notably the cranial walls. In this case the membranes are nearly always involved. The dura shows a necrotic perforation resembling that found with internal perforation of a mastoid or tympanic abscess. The pia is thickened and covered with a tough fibro-purulent exudation; occasionally the dura and leptomeninges are fused into a continuous mass of the consistency of leather through the agglutinating exudation. The abscess is usually found open, and it is not yet determined whether it begins as a surface erosion, and, bursting through the cortex, spreads rapidly on reaching the white substance, or not. The white substance is much more vulnerable to the assault of suppurative inflammation than the gray, and not infrequently the superficial part of the cortex may appear in its normal contiguity with the pia, but undermined by the cavity of the abscess, which has destroyed the subcortical tissue. Possibly the infecting agent, as in some cases of ear disease, makes its way to the brain-tissue through the vascular connections, which, however sparse at the convexity of the brain, still exist.

CLINICAL HISTORY.—The symptoms of a cerebral abscess depend on its location, size, and rapidity of formation. There are certain parts of the brain, particularly near the apex of the temporal lobe and in the centre of the cerebellar hemisphere, where a moderately large abscess may produce no special symptoms leading us to suspect its presence. There are other localities where the suppurative focus⁵³ indicates its presence, and nearly its precise location and extent, by the irritative focal symptoms which mark its development and by the elimination of important functions which follows its maturation. It is also in accordance with the general law governing the influence of new formations on the cerebral functions that an acutely produced abscess will mark its presence by more pronounced symptoms than one of slow, insidious development. Indeed, there are found abscesses in the brain, even of fair dimensions, that are called latent because their existence could not have been suspected from any indication during life, while many others of equal size are latent at some time in their history.

⁵³ Practically, our knowledge of localization of functions in the human brain begins with the observation by Hitzig of a traumatic abscess in a wounded French prisoner at Nancy named Joseph Masseau. The year of the publication of this interesting case constitutes an epoch in advancing biological knowledge, which will be remembered when even the mighty historical events in which Hitzig's patient played the part of an insignificant unit shall have become obsolete. This, the first case in the human subject where a reliable observation was made was an unusually pure one; the abscess involved the facial-hypoglossal cortical field (Archiv für Psychiatrie, iii. p. 231).

An acute cerebral abscess is ushered in by severe, deep, and dull headache, which is rarely piercing, but often of a pulsating character. The pain is sometimes localized, but the subjective localization does not correspond to the actual site of the morbid focus.⁵⁴ It is often accompanied by vertigo or by a tendency to dig the head into the pillow or to grind it against the wall. With this there is more or less delirium, usually of the same character as that which accompanies acute simple meningitis. As the delirium increases the slight rise in temperature which often occurs in the beginning undergoes an increase; finally coma develops, and the patient dies either in this state or in violent convulsions. The case may run its course in this way in a few days, but usually one to three weeks intervene between the initial symptoms and death.

⁵⁴ Although Ross seems to be of a contrary opinion, it is the exception for the pain to correspond in location to the abscess.

Between the rapid and violent course of acute cerebral abscess detailed, and the insidious course of those which as latent abscesses may exist for many years without producing any noticeable symptoms whatever, there is every connecting link as to suddenness and slowness of onset, severity and mildness of symptoms, and rapidity and slowness of development and progress. It is the encapsulated abscesses which are properly spoken of as chronic, and which may even constitute an exception to the almost uniform fatality of the suppurative affections of the brain. Thus, the symptoms marking their development may correspond to those of an acute abscess, but coma does not supervene, temporary recovery ensues, and the patient leaves the hospital or returns to his vocation. But all this time he appears cachectic, and there will be found, on accurate observation, pathological variations of the temperature and pulse. The appetite is poor; the bowels are usually constipated; there are frequent chilly sensations and horripilations, and a general malaise. This condition slowly passes away in the few cases which recover; in others relapses occur, usually of progressing severity, and terminate life. The period during which the symptoms of the abscess are latent may be regarded as corresponding to the latent period which sometimes intervenes between an injury and the development of the symptoms of acute abscess, and which, according to Lebert, may comprise several weeks or months. In other words, the morbid process may be regarded all this time as progressing under the mask of a remission. It is this latent period which it is of the highest importance for the diagnostician to recognize. There is usually headache, which is continuous and does not change in character, though it may be aggravated in paroxysms. Usually the temperature rises with these paroxysms, and if they continue increasing in severity they may culminate in epileptic convulsions.