[Juvenile type of subacute necrotizing encephalomyelinopathy (Leigh) with unusual CNS-localisation].

The case of an adolescent girl aged 16 with subacute necrotizing encephalomyelopathy (Leigh) is reported. The chronic course of illness lasting for 7.5 years was characterized by visual and gait disorders progressing to blindness, incomplete spastic tetraparesis, and fatal respiratory insufficiency. Neuropathology, in addition to CNS lesions with typical pattern, revealed involvement of Ammon's horn, fornix, corpora mammillaria, tractus mammillothalamicus, and corpus callosum. The massive damage to the total Ammon's horn formation, the distribution of which correlates to none of the established patterns of lesion, is related to the primary disease given, and an additional secondary transneuronal degeneration of associated systems is suggested.