Psychiatric manifestations associated with mega cisterna magna.

The Dandy-Walker variant is a milder form of the Dandy-Walker complex and is characterized by normal-sized posterior fossa, mild vermian hypoplasia, and a cystic lesion that communicates with the fourth ventricle. This syndrome has been described in association with schizophrenia, obsessive-compulsive disorder, manic episode, psychosis (delusional type), and recurrent catatonia. The authors present two cases of mega cisterna magna associated with mania and catatonic schizophrenia.