In normal pressure hydrocephalus, all are seen except-

Normal Pressure Hydrocephalus is an uncommon syndrome consisting of  an abnormal gait (ataxia or apractic) dementia (usually mild to moderate) urinary incontinence This is a communicating hydrocephalus with patent aqueduct of Sylvius. NPH is presumed to be caused by obstruction to normal flow of CSF over the cerebral convexity and delayed absorption into the venous system. The indolent nature of process results in an enlarged lateral ventricles but  relatively little increase in CSF pressure. Following conditions have been seen to cause NPH by producing scarring of basilar meninges (blocking upwards flow of CSF) meningitis subarachnoid haemorrhage head injury Approx 30-50% of the patients of NPH will show improvement with a ventricular shunting procedure.