Acute hemicerebellitis with obstructive hydrocephalus in a young adult.

Background: Acute cerebellitis is a rare entity, described in the pediatric population, usually of viral or autoimmune origin, bilateral and symmetric, and with good prognosis. Only 13 cases of unilateral cerebellitis have been reported thus far. To the best of our knowledge, this is the first case of hemicerebellitis in the literature reported in a young adult that caused acute hydrocephalus requiring surgical treatment.