Acute opercular syndrome in 4-year-old boy.

Acute opercular syndrome is a rare described syndrome caused by a sudden damage of the cerebral cortex and subcortical white matter, located around the insula. A rare cause of this syndrome can be an infectious agent, particularly herpes simplex virus. Quick diagnosis and immediate initiation of treatment significantly reduce the risk of neurological consequences and mortality. We present a case of encephalitis of unknown etiology and severe course, with the symptoms of acute opercular syndrome in 4-year-old boy.