Southard[162] has called attention to the margin of error in the diagnosis of senile psychoses. Forty-two cases unanimously diagnosed as "senile dementia" were "reviewed clinically and anatomically, with a surprisingly low general percentage of accuracy (sixty-six per cent) where either cerebral atrophy or cortical arteriosclerosis or both were regarded as confirmatory, and with still lower percentages: (48 per cent) where cortical arteriosclerosis was considered essential and (38 per cent) where cerebral atrophy was considered essential for a correct diagnosis." It is significant that exactly one-third of the cases studied were found by Southard to more properly "belong in a group of acute psychoses or other mental diseases occurring in old age but not dependent on recognizable senile changes." CHAPTER III THE PSYCHOSES WITH CEREBRAL ARTERIOSCLEROSIS Sufficient weight has not been attached heretofore to the important influence of cerebral arteriosclerosis in the production of mental diseases. Unquestionably it has been a complicating factor in many of the generally recognized psychoses which has not been given adequate consideration. Its relation to involution melancholia as well as the presenile and senile disorders has been given a great deal of attention, but cannot as yet be clearly defined. Only in its syphilitic forms can it be looked upon as contributing to the clinical picture in general paresis. It is, however, productive of late deterioration in the chronic alcoholic conditions and in the manic-depressive psychoses occurring in advanced years. It plays a part frequently in the terminal stages of dementia praecox. In paranoia and the paranoid conditions of long standing it often becomes a factor to be reckoned with. Certainly in the differentiation of the epilepsies of the aged it must be taken into definite account. The importance of arteriosclerosis, a term used first by Lobstein some seventy-five years ago, has long been recognized. Osler in referring to this subject made the following interesting comment:—"To a majority of men death comes primarily or secondarily through this portal. The onset of what may be called physiological arteriosclerosis depends, in the first place, upon the quality of arterial tissue (vital rubber) which the individual has inherited and secondarily upon the amount of wear and tear to which he has subjected it. That the former plays the most important rôle is shown in the cases in which arteriosclerosis sets in early in life in individuals in whom none of the recognized etiological factors can be found. Entire families sometimes show this tendency to early arteriosclerosis, a tendency which cannot be explained in any other way than that in the make-up of the machine bad material was used for the tubing."