Abstract

Symptomatic hydrocephalus after subarachnoid haemorrhage seems to result both from mechanical obstruction of arachnoid villi and basilar cisterns and from an inflammatory cellular reaction in the villi. Subarachnoid haemorrhage was induced in rabbits using whole blood injected through an implanted intraventricular needle. Control rabbits receiving intraventricular methyl prednisolone acetate but no blood, developed ventricular dilation significantly more often than untreated controls. Eighty-three per cent of rabbits with untreated experimental subarachnoid haemorrhage developed moderate to severe hydrocephalus. Intramuscular steroid therapy significantly reduced the incidence of hydrocephalus.