Page:The American Cyclopædia (1879) Volume III.djvu/203

 BRAIN (DISEASES) 197 ished by tho regulation of diet and sedative remedies. In all cases, while the body should be well nourished, it is desirable to prevent or remove, by dietetic and other measures, that morbid condition of the blood known as ple- thora. Within tho past few years a class of remedies the bromides of potassium, ammo- nium, sodium, and calcium have been intro- duced, which appear to diminish, by an effect upon the vessels, the amount of blood within the head. These remedies, at all events, have been found by experience to be useful in cases of cerebral congestion. In severe cases, char- acterized by active delirium or apoplectic coma, bloodletting will not only produce speedy relief, but, timely resorted to, it may rescue from impending death. If the symptoms and danger do not call for this potent measure, an active cathartic, especially croton oil, is prompt- ly effective. Ligatures applied to the extremi- ties may sometimes be substituted for bleeding. Cold applied to the head, in the form of either the douche or ice cap, is highly useful, and with these may be conjoined warm and stimulating applications to the extremities. Passive conges- tion, that is, an overplus of venous blood within the skull, is an effect of various causes which interfere with the return of blood from this part of the body. The pressure of the thyroid bodies when greatly enlarged (goitre), enlarged lymphatic glands, and tumors in the neck press- ing on the jugular veins have this effect. Aneu- rismal or other tumors within the chest produce the same effect by pressure on the descending vena cava. A not infrequent cause belonging in this category is an obstruction to the passage of the blood into the right side of the heart, the obstruction being due to dilatation of the right auricle and ventricle, resulting from an obstacle to the circulation through the pulmo- nary organs, incident either to valvular lesions at the mitral orifice within the heart or to affections of the lungs themselves. Of the latter, pulmonary emphysema is tho affection which especially leads to this result. Passive congestion from these causes, even when con- siderable, is often tolerated without great in- convenience. The face is more or less congest- ed, and if the congestion be great, there may be lividity or blueness especially marked in the space over the lips intervening between the skin and mucous membrane, which is called the prolabia. As regards the symptoms refer- able to the brain, passive congestion occasions a dull pain, a sense of fulness, sluggishness of the perceptions and the intellectual faculties, and defective or disturbed sleep. Occurring as an effect of the causes which have been named, the condition admits of relief only so far as these causes can be diminished ; and in many cases this is impracticable. There is another cause of passive congestion within the skull, incident to the fact that the brain is removed from atmospheric pressure owing to the solidity and occlusion of the bones of the cranium, and also to the fact that the brain is not compressi- ble to much extent by the forces which gov- ern the intracranial circulation. The cranium forming a closed box capable of resisting the pressure of the atmosphere, and the substance of the brain not yielding much to the pressure of blood within the vessels, it follows that whenever the supply of arterial blood is lessen- ed, a suction force is exerted upon the blood in the veins, and more or less passive congestion of the brain is a consequence. Passive conges- tion, thus produced, is supposed to he a morbid element in affections which involve a dimin- ished supply of blood to the head. The latter is an effect of impoverishment of the blood and of deficient power of the heart's action. This element is supposed to account for certain head symptoms occurring especially in children affected with cholera infantum. The blood in this affection is impoverished by profuse dis- charges from the stomach and bowels, and the heart's action becomes enfeebled thereby. These head symptoms, namely, morbid somno- lency, semi-coma, and sometimes convulsions, were formerly considered to denote either in- flammation of the meninges of the brain or serous effusion, affections which were embraced under the name hydrocephalus ; hence, as simulating these conditions, the passive congestion pro- duced in the manner just stated has been called the hydrencephaloid affection. The proper treatment of this affection embraces measures to restore the normal condition of the blood and the strength of the heart by alimentation, tonic remedies, and the judicious use of alco- holic stimulants. The treatment heretofore employed, based on the supposition of inflam- mation and effusion, was not only without good effect, but hurtful. It must be admitted that in cases of passive congestion from a de- ficiency of the supply of arterial blood, it is not certain how far the morbid phenomena are attributable to the congestion, and how far directly to the lack of the arterial blood. II. OEBEBEAL ANEMIA. The term ansemia is used in medical writing and conversation to denote a morbid condition of the blood, namely, a pau- city of the red globules. This is the condition which is understood when the blood is said to be impoverished. The term also denotes a morbid deficiency of blood in any of the organs of the body. The name cerebral anasmia im- plies tho latter sense of the term. The affec- tion therefore consists in a morbid deficiency of blood within the skull. The anwmia from cer- tain causes is general, that is, it affects the entire contents of the skull ; or it may be limited to a portion of the brain, the latter being incident to causes affecting branches of the intracranial arteries. An effect of general cerebral anaemia, existing in a marked degree and suddenly in- duced, is the occurrence of syncope, fainting, or swooning. In this condition there is loss of consciousness, the face becomes deadly pale, and there are convulsive movements with gasping for breath, the person appearing to be upon the brink of dissolution. Tho condition, indeed, is