The patient, an 8-year-old boy, was given ACTH therapy for symptoms ascribed to nephrosis. On the 51st day (October 7, 1951) of the third period of the treatment (see table 1) he complained of intense headache and, the next day, convulsive seizure occurred. His blood pressure arose during this period to 220-130 mm Hg and cerebrospinal fluid showed hypertension. During the next four days the child was in a coma and later became confused. In the weeks that followed, he improved but the hypertensive encephalopathy caused, as the most important neurologic damage, severe visual disorders. At first, he was totally blind; afterwards he showed disturbances of recognition, in the form of a complete visual agnosia, for objects, persons, symbols and colors. This condition has continued until today.