Anomalies of the encephalic arteries among the insane. A study of the arteries at the base of the encephallon in two hundred and twenty consecutive cases of mental disease, with special reference to anomalies of the circle of Willis

Minor anomalies of the encephalic arteries are so common that their study and observation have been mainly confined to modifications of the circle of WILLIS and the principal basal trunks.Slight deviation from the normal is very common in my autopsies and probably in most cases unimportant, though it is claimed that anomalies of the basal trunks are more common in the insane, to quote BERKLEY, indicating some defect in the "molding of the vital clay."BERKLEY admits, however, that comparative statistics are wanting, while he states that in four cases out of sixteen the arteries showed anomalies, a very large proportion.It would seem evident that developmental defects in the arteries would in most cases be compensated for by modifications of other trunks; and that under normal conditions functions would be preserved, but under diseased states and possibly unusual circulatory disturbances the abnormality might be of serious importance.T h e actual aetiological relationship of arterial anomalies to mental diseases other than to defective developmental states, in which it may be inferred, is hard to establish; but the relation they bear to gross cerebral disease, and to surgical operations upon the cervical arteries is easily demonstrated.It must be borne in mind in the study of these anomalies that