This study is a randomized, double-blind, placebo-controlled clinical trial investigating the potentially beneficial effects of systemic recombinant human erythropoietin therapy (Epoetin beta, NeoRecormon®, Roche, 30000IU/50 ml/30 min, three times in the first week) on cerebral autoregulation and incidence of delayed ischemic deficits (DID) following aneurysmal subarachnoid haemorrhage (SAH).