HYDROCEPHALUS secondary to aqueductal stenosis is predominantly a disorder of childhood, though its occurrence in adults is well known.1-6Pennybacker5describes distinct "juvenile" and "adult" syndromes of aqueductal stenosis, but clinical manifestations vary widely. Asymptomatic cases have been found at routine postmortem examination. Kernohan and Sayre7consider that "gliomas strategically placed in the aqueduct of Sylvius are in all probability the smallest tumors in the human body that lead to the death of the patient." More commonly the stenosis proves to be of nonneoplastic origin.8Two patients we have seen during the past year fall in this latter category. Report of Cases CASE 1.—This 52-year-old canteen checker (BVAH#071060) noted onset of slowly progressive gait disturbance in 1958, shortly following the death of his mother, to whom he was closely attached. His wife complained of the patient's gradually failing ability to perform sexually. He