Isolated fourth ventricle in neurocysticercosis: pathophysiology, diagnosis, and treatment.

Four cases of isolated fourth ventricle in neurocysticerocosis are reported (three after ventriculoperitoneal shunting, and one after hydrocephalus without shunting). Diagnosis was made based on computed tomography (CT) and/or CT cisternogram/ventriculogram. Three patients underwent fourth ventricle drainage (two died and the third remains well). The fourth patient refused surgical treatment and continues to have severe ataxia. Diagnosis, pathophysiology, and treatment of this entity in neurocysticercosis are discussed.