Subacute diencephalic angioencephalopathy: an entity similar to angiodysgenetic necrotizing encephalopathy and Foix-Alajouanine disease.

A previously healthy 58-year-old man developed neurological illness with progressive dementia, hallucinations, central motor and vegetative impairment which led to death in 14 weeks. Autopsy revealed lesions in a symmetrical centrencephalic distribution. Inner cerebral veins and arteries were surrounded by extravasation of plasma and perivascular haemorrhage and were thickened by fibrous scarring and muscle fibre proliferation. Necrotized blood vessels were also found. The parenchyma was damaged by incomplete to complete necrosis. The age and sex of the patient, the progressive clinical course, the increase of cerebrospinal fluid protein, and the histopathology of the lesion show some similarities to angiodysgenetic necrotizing encephalopathy and spinal Foix-Alajouanine disease.