In some cases, however, the thickening of the artery may interfere with, without completely interrupting, the circulation in the part to which it is distributed, and the degree of the interference may vary from time to time. If, then, in a person whose age and general physical condition, as shown by the state of the tangible arteries, arcus senilis, complexion, and so forth, render the existence of atheromatous arteries in the brain probable, cerebral symptoms of an ill-defined character arise, it is very probable that they are the result of irregularities in the circulation dependent on atheroma.
This state of things is to be distinguished from the more clearly marked conditions which have already been described, partly by the incompleteness of the attack, and partly by its changes in severity and character from time to time—a paralysis undergoing alternations of improvement and the reverse from day to day, delirium appearing and disappearing in correspondence with the general health, the vigor of the heart, and the state of the digestive organs.
The diagnosis between these incomplete anæmias and an almost precisely similar result of syphilitic endarteritis is to be made chiefly by the history and age. In middle-aged persons general paralysis might present a not very different set of phenomena. A tolerably distinct, but not severe, hemiplegia in an old person, subsiding in a few hours under the influence of a cathartic, and perhaps returning more than once, may often be due to a local and temporary anæmia from atheroma, as well as to slight hemorrhage or a not completely occluding thrombus.
On the other hand, extensive atheroma may exist without serious impairment of the cerebral functions, provided it be evenly distributed and do not interfere with the passage of blood in any one vessel.
The prophylaxis of atheroma has already been considered. We do not know of any drug that can change the nature or extent of the processes going on in the arterial walls, but if any influence can be exerted it is through dietetic and hygienic means.
The consequences of rigidity of the arterial walls, as productive of resistance to the passage of blood, can be warded off to some extent by promoting the vigor of the heart. Treatment should therefore be directed to the improvement of the nutrition of the body in general and the heart in particular. Heart tonics and laxatives are the classes of medicaments most likely to be useful. Perhaps it is to its effect in increasing the force of the heart contractions, like digitalis, that coffee owes its reputation as a preservative from apoplexy.
ATROPHY AND HYPERTROPHY OF THE BRAIN.
BY H. D. SCHMIDT, M.D.