Case report and review of the literature: arachnoid cyst of the fourth ventricle presenting as a syndrome of normal pressure hydrocephalus.

The Authors report a case of 4th ventricular arachnoid cyst that presented clinically with the criteria of normal pressure hydrocephalus (NPH). Only a few cases of intraventricular arachnoid cyst have been recorded in the literature; the present case is the second reported case diagnosed as a syndrome of NPH.