Severe type Hunter's syndrome. Polysomnographic and neuropathological study

The clinico-pathological and polysomnographical findings of an adult male patient with severe type of Hunter's syndrome are presented. He died of respiratory failure aged 19, which was much older than the average in this disease. Mucopolysaccharidosis was suspected at the age of one year, and diagnosed by leucocyte enzyme assay at 4 years of age. Mental and physical activity gradually deteriorated until his death. He often showed central type sleep apnea during the sleep stage 2, in addition to common obstructive apnea in Hunter's syndrome. The autopsy showed marked fibrous thickening of the endocardium and valves, enlargement of the liver and spleen, dilatation of the lateral ventricles and diffuse atrophy of the brain. Histologically, diffuse cytoplasmic vacuolations were found in fibroblast-like cells in the thickened endocardium and vascular walls, in Kupffer cells, and in many neurons of the central and peripheral nervous systems. Most neuronal inclusions were considered to be a ganglioside, and in other cells to be a mucopolysaccharide, by their ultrastructure. Massive accumulation of ganglioside in the neurons in the respiratory center might be reflected on central type sleep apnea.