Paired helical filaments in neurovisceral lipidosis (juvenile dystonic lipidosis).

Paired helical filaments, the ultrastructural substrate of Alzheimer neurofibrillary change, were found in great number in a 29-year-old patient with neurovisceral lipidosis. The abnormal filaments were frequently present in the distended neurons and axons. The clinical, pathological, and ultrastructural findings were consistent with juvenile dystonic lipidosis, which is considered to be a variant of type C Niemann-Pick disease. The association of Alzheimer neurofibrillary change and central nervous system lipidosis is reviewed.