Page:The American Cyclopædia (1879) Volume III.djvu/205

 BRAIN (DISEASES) 199 take place in some cases, and more or less hemi- plegic paralysis then remains. Hemiplegia, either transient or persisting, is in like manner an effect of thrombosis. It is generally devel- oped gradually, and is not so likely to give rise to. sudden coma or apoplexy, because, the coagula- tion not taking place all at once, the obstruction occurs more or less gradually. III. CEEEBRAL H^EMOKBHAGE. Haemorrhage within the cra- nium may take place, first, either into the sub- stance of the brain or the spaces known as the ventricles, and second, between the membranes investing the brain. The name cerebral hsem- orrhage is applied especially to an extravasa- tion in the two former of these situations. Sit- uated between the membranes, it is distinguish- ed as meningeal haemorrhage. Haemorrhage very rarely takes place primarily within the ventricles of the brain ; when blood is found here, the seat of the extravasation is generally in the cerebral substance, and the blood has thence made its way into the ventricles. Hrom- orrhage is the most frequent of the several morbid conditions giving rise to the sudden loss of consciousness which characterizes an apo- plectic attack. In the great majority of the cases of apoplexy caused by this condition, the haemorrhage takes place in the substance of the brain. The extravasation is seated in either the corpus striatum or the thalamus options much oftener than in any other of the anatom- ical divisions of the brain ; it may, however, occur in any portion of the cerebral substance. The quantity of blood which escapes varies greatly in different cases. If very large, death may occur within a few hours. Sudden or almost instantaneous death, however, is very rarely if ever caused by cerebral haemorrhage. If the extravasation be small, the patient emerges after some hours from the coma or apoplectic state ; the clot may subsequently be absorbed, and re- covery may take place, with more or less perma- nent injury of the brain. An apoplectic attack dependent on hajmorrhage into the substance of the brain is almost always accompanied by paralysis of the muscles of the limbs, and gene- rally also of certain of the muscles of the face on one side of the body (hemiplegia). This is always a concomitant of an extravasation into the corpus striatum, or the motor tract of the fibres of the brain. The paralysis of the limbs, and generally also of the face, is on the side opposite to the cerebral hemisphere in which the haemorrhage is seated. In some cases in which the extravasation is small, or in which it takes place slowly, hemiplegia, without apo- plexy, is the effect. Hemiplegia, in the cases of apoplexy dependent on haemorrhage into the substance of the brain, persists after the apoplectic state disappears ; and in general this form of paralysis in a greater or less de- gree continues permanently, even when the ex- travasated blood has been absorbed. After an apoplectic attack from cerebral haemorrhage, the mental faculties generally become more or less impaired. The degree of impairment will depend on the amount of injury which is the immediate effect of the hajmorrhage, and on the disorganization due to the inflammation excited by the presence of the clot. It is also to a cer- tain degree dependent on the diminished exer- cise of the mental faculties which is usual after an attack of apoplexy. Cerebral hemorrhage is generally a consequence of disease of the ar- teries of the brain. They are liable to become instantaneously fatty, and to be rendered brittle by the deposit of calcareous matter. Hence, either with or without some unusual tension, such as is caused by violent muscular efforts or intense mental excitement, they give way, and extravasation occurs. Another condition favoring rupture is the formation of minute di- latations, which are called miliary aneurisms. These changes in the arteries rarely take place prior to middle age ; hence, apoplexy and hemi- plegia dependent on cerebral hajmorrhage sel- dom occur in youth. During an attack of apo- plexy dependent on extravasation of blood, lit- tle is to be done in the way of treatment be- yond keeping the body of the patient quiet, with the head raised, removing all articles of clothing which make pressure on the neck or chest, and applying cold to the head. Bleed- ing under these circumstances, which was for- merly resorted to, is now rarely employed. An active cathartic is generally given. If the pa- tient emerge from the comatose state, the ob- jects of treatment are the promotion of absorp- tion of the clot, the prevention of a repetition of the haemorrhage, and the recovery as far as practicable from the paralysis. As the changes in the vessels which occasioned the haemorrhage continue, its recurrence is always to be apprehended. Yet not unfrequently life continues for many years and a second haemor- rhage does not occur. It is important to add that cerebral haemorrhage is seldom preceded by premonitory symptoms. Hence, in general, vertigo, ringing in the ears, and other symp- toms which naturally lead persons to anticipate an attack of apoplexy, are not to be thus inter- preted. Much relief from needless apprehen- sions may often be afforded by recollecting the statement just made. Haemorrhage situated between the membranes of the brain, or menin- geal haemorrhage, is extremely infrequent in comparison with extravasation in the cerebral substance. This statement is especially true if cases in which meningeal haemorrhage is attrib- utable to injuries received on the skull be ex- cluded. The latter are distinguished as trau- matic cases. Excluding these, the seat of the haemorrhage is generally beneath the arachnoid membrane. The blood escaping in this situ- ation may be more or less diffused over the sur- face of the brain, remaining beneath the arach- noid membrane ; or this delicate membrane may be ruptured, and then the blood is diffused over the brain within the arachnoid cavity, be- tween the arachnoid and the dura mater. A small quantity of blood in this situation may not give rise to serious results, and it may even