Juvenile dystonic lipidosis: an unusual form of neurovisceral storage disease.

An unusual neurovisceral lipid storage disorder in two unrelated juvenile patients manifested itself by dystonia and involuntary movements, with facial grimacing, dysarthria, gait difficulty, and impaired manual dexterity. Supranuclear paresis of vertical gaze and splenomegaly were present. Absent were seizures, major intellectual deterioration, spasticity, or blindness. Histiocytes showed lysosomal storage of various phospholipids, cholesterol, neutral lipids, and autofluorescent material. Appendiceal neurons showed only an increse of phospholipids by histochemistry. Neuronal deposits differed ultrastructurally from these in histiocytes. Leukocyte sphingomyelinase activity was normal. The nosology of this disease and its relationship to so-called juvenile types of Niemann-Pick disease is discussed. The primary metabolic defect in these patients remains unknown.