Astrocytic cytoplasmic inclusions within an epileptic focus in an otherwise neurologically intact patient.

A 17-year-old woman with intractable seizures since infancy underwent resection of an epileptic focus in the left frontal cortex. The cytoplasm of many cortical astrocytes contained amorphous eosinophilic inclusions, which ultrastructurally were non-membrane bound and consisted of densely packed osmiophilic material. Similar inclusions have previously been observed, at autopsy, in patients with unspecified mental retardation and various brain malformations. The present report is unique in that the inclusions were detected in the resected specimen of an epileptic focus. The patient is neurologically intact except for the seizures that presently are totally controlled by the surgery. The pathogenesis of these inclusions is unclear. The fact they occurred in an epileptic focus raises the possibility that prolonged seizures or its underlying precipitating factors may cause conglutination of an indeterminate element of the protoplasmic astrocytes resulting in inclusion formation.