A CASE OF LATE INFANTILE AMAUROTIC IDIOCY OF THE MYOCLONUS TYPE

Abstract

A case of progressive encephalo-pathy in a boy who died at the age of 4 1/2 years is reported. There were no similar cases in the family, and the parents were not related. The illness began at the age of 12 months with epileptic attacks which increased in frequency and were unaffected by medical treatment. There was increasing dementia, and during the last 6 months of life the patient was bed-ridden, and could neither see nor speak. There were almost continuous athetoid movements of the body and limbs and frequent myoclonic contractions, especially in the arms. Ophthalmological examination revealed nothing difinitely abnormal, in particular there was no cherry red spot. There were no abnormal vacuoles or granules in the lymphocytes. Electroencephalogram (EEG) revelaed severe diffuse arrhythmia with slow activity and spikes. PEG revealed moderate diffuse dilatation of the ventricular system. The cell and protein content of the cerebrospinal fluid (CSF) were normal. Muscle tonus became exaggerated, and the reflexes hyperactive. Autopsy revealed accumulation of lipoprotein in the ganglion cells of the central nervous system (CNS), dysplasia of the cerebellum, and myoclonus bodies, consisting mainly of lipids, in the substantia nigra, dentate nucleus, and thalamus. These findings are discussed and compared with similar cases from the literature. It is concluded that the case was one of late infantile amauro-tic idiocy of the myoclonus type.