Objectives: Severe post-hemorrhaghic internal hydrocephalus with almost complete atrophy of the cerebral parenchyma, as in the following case, is rare. Case report: A 19yo Caucasian female with a history of premature birth, perinatal intraventricular bleeding, developmental delay, mental retardation, and epilepsy, was admitted for recurrent generalized tonic-clonic seizures. She was able to produce some noises but was unable to communicate with understandable speech. There was severe mental retardation, motor deficits, and tetraspasticity. She was able to sit and eat but was otherwise dependent on the parents’ support. Monotherapy with primidon since age 15y was increased to 500mg/d. A CT scan of the cerebrum showed a massive internal hydrocephalus with atrophy of the basal ganglia, the white matter, the cerebellum, but also the cortex. Neurosurgeons decided against a shunt. Conclusions: Despite severe atrophy of the cerebral parenchyma, severe post-hemorrhagic internal hydrocephalus, manifesting as psychomotor retardation, epilepsy, and tetraspasticity, is compatible with life.