[Significance and prognostic value of Parinaud's syndrome in hydrocephalus (author's transl)].

Eleven out of 260 cases of chronic hydrocephalus in adults were associated with mesencephalic symptoms, in particular Parinaud's ophthalmoplegia. Investigations aimed at detecting intracranial growth consistently gave negative results. In most cases, the midbrain symptoms were accompanied by intracranial hypertension and therefore reflected an aggravation of the hydrocephalus. They regressed when manoeuvres tending to reduce intracranial pressure were applied on time. On three occasions, they were followed by pontobulbar symptoms and treatment was ineffective. When brain stem symptoms (especially Parinaud's syndrome) occur in the course of hydrocephalus, one should always look for tumoral lesions, but they may also point to deterioration of the disease, which should be treated before it becomes irreversible. The mechanism of brain stem involvement in hydrocephalus is discussed in the light of electrophysiological recordings during experimentally-induced intracranial hypertension in the cat.