Intermittent obstructive hydrocephalus in the Arnold-Chiari malformation.

A 26-year-old woman with a Chiari-I malformation and intermittent symptoms of intracranial pressure elevation is described. Clinically, papilledema was accompanied by midperipheral retinal hemorrhages. Repeat computed tomographic scans and lumbar puncture showed normal results. Posterior fossa-directed magnetic resonance image scanning revealed the Chiari-I malformation. Intraventricular monitoring was necessary to demonstrate the marked but unsustained elevation of intracranial pressure.