Neuronal degeneration in subacute necrotizing encephalomyelopathy (Leigh's disease). Case report.

We report clinical, radiological and pathological findings in a 5-year-old girl who died of subacute necrotizing encephalomyelopathy (SNE) after 4 weeks of illness. Autopsy revealed endothelial swelling and vacuolar degeneration of the neuropil in the brain, brain stem and cerebellum. In addition, the affected areas showed degeneration of the neurons which was different from anoxic nerve cell damage both with regard to morphological picture and topographical distribution. This neuronal degeneration was probably due to the underlying metabolic defect in SNE per se and resembled in several aspects the nerve cell changes seen in the thalami and inferior olives in active Wernicke's encephalopathy. It is our opinion that more attention should be paid to the nerve cell degeneration in SNE rather than focusing on the relative preservation of these cells.