[Parinaud's syndrome in non-tumorous hydrocephalic intracranial hypertension].

Four cases (3 children and one adolescent) are presented in which Parinaud's syndrome developed in the course of progressive non-tumorous hydrocephalus. The vertical gaze palsy completely disappeared in all cases some days after raised intracranial pressure had been successfully treated. Neuroradiological findings indicate that Parinaud's syndrome can be elicited by a dorsal midbrain compression due to a markedly dilated suprapineal recess. Other contributing factors as distortion and compression of distal branches of the posterior cerebral artery in the cisterna ambiens region and an axial caudal displacement of the oral brain stem may be involved. According to the few cases published in the literature, the vertical gaze palsy seems to occur predominantly in benign connatal aqueduct stenosis and may then be regarded as a relatively early symptom of decompensating hydrocephalic intracranial pressure.