[Concentric sclerosis (Baló)].

Seventeen autopsy cases were collected in the Philippines. Mean age of onset 32.5 years, male/female ratio 1/2, no seasonal change, and the patients' occupation variable. A half had prodromal symptoms: mild fever, general malaise and headache. The disease was characterized by acute onset with behavioral changes, reticence, hemi- or quadriplegia with pyramidal signs, and incontinence. A quarter of patients had generalized seizure. There were no specific abnormalities in the routine blood examination, and CSF showed unexpectedly mild change. CT scan and MRI show diffuse or multifocal abnormalities in the centrum semiovale. They died of cerebral herniation or secondary infection. The brain was characterized by diffuse or multifocal necrotic and concentric demyelination in the cerebral white matter with marked gemistocytosis.