title: Cryptogenic spontaneous subarachnoid haemorrhage.
abstract: Patients with spontaneous primary subarachnoid haemorrhage (SAH) in whom initial diagnostic investigation, including cerebral four-vessel angiography, does not reveal a cause, present a difficult problem. In a series of 95 patients a cause became apparent in about 10% of cases during the first three weeks, predominantly missed aneurysms. After three weeks the clinical evolution was benign. Cryptogenic SAH seems to be a disease of its own, but in the individual case the possibility of missed aneurysm or later of no re-bleed aneurysm always remains.
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000175:diagnosis; D002538:Intracranial Arteriovenous Malformations / Q000150:complications; D008297:Male; D008875:Middle Aged; D013345:Subarachnoid Hemorrhage / Q000209:etiology*