A clinical study of 44 patients with juvenile amaurotic family idiocy.

The material presented comprises 44 patients with juvenile amaurotic family idiocy. The disease is distinguished from other types of gangliosidoses, and earlier clinical descriptions are reviewed. The median age of the patients at the onset of the diseases was 5.8 years and median duration of life was 18.8 years. It appears probable that the disease takes two different courses. Besides the earlier described accompanying phenomena, dystonic attack with oculogyre crises have been found in some patients, as well as extreme cases of bradycardia. In 77% of the patients psychotic manifestations have been found, chiefly in the form of frightening visual hallucinations. The pathogenesis and clinical observations of the psychoses are discussed and environmental factors are pointed out as contributing to the pathogenesis of the psychoses.