Natural course of intracranial pressure and drainage of CSF after recovery from subarachnoid hemorrhage.

Twenty-eight patients were followed 12 months or longer after recovery from subarachnoid hemorrhage (SAH). The examination included spinal infusion test (SIT), clinical evaluation and cerebral computertomography (CT). The results indicate that when resting pressure and drainage of CSF are within normal limits 3 months after the hemorrhage there is little if any risk of developing late communicating hydrocephalus. In this study, most patients with a moderate impaired CSF drainage and/or slightly increased resting pressure 3 months after SAH did not show any increase in the ventricular size or clinical deterioration during the follow-up period. None of the 28 patients developed late communicating hydrocephalus or the clinical picture of normal pressure hydrocephalus.