The form of presenile psychosis known as Pick's disease was first described in 1892, by Arnold Pick,1of Prague, who recorded a series of cases2in which progressive dementia was invariably associated with aphasia occurring in old age and in which autopsy showed circumscribed atrophy of the cerebral cortex. Up to the present time about seventy pathologically verified cases have been reported, and both the clinical and the pathologic aspects of the disease have been the object of painstaking investigations. The age of onset falls generally between 45 and 60 years, in the so-called presenium. Women are more affected than men, the ratio being 2:1. The duration of the disease is from two to ten years; the course is progressive and the prognosis decidedly ominous. Acute and chronic forms have been distinguished. Clinically the disease is characterized by the association of progressive psychosis with neurologic signs of gradual