The adult form of subacute necrotizing encephalopathy.

The rare adult form of subacute necrotizing encephalopathy in a 49-year-old man is reported. Six months before admission the previously healthy and nonalcoholic patient developed progressive hemiparesis of the left side and instability of gait. Ventriculography revealed marked narrowing of the aqueduct, and after ventriculocisternotomy the patient became akinetic and mute. The post-mortem histologic examination revealed pathologic changes characteristic of subacute necrotizing encephalopathy. This case demonstrates that this rare disease in an adult may cause both akinetic mutism and aqueductal stenosis.