Poor Grade Aneurysmal Subarachnoid Hemorrhage Study Group

Multicentric registry study in order to define outcome, predictors, treatment effects and their modifiers in poor grade aneurysmal subarachnoid haemorrhage patients. The search for outcome predictors is going to be subdivided into three main research areas: 1. outcome predictors in the emergency department (so called "early brain injury phase"). 2. outcome predictors in the neurocritical care unit (so called "delayed brain injury phase"). 3. Treatment strategies. Two other areas of research are identified: delayed cerebral ischemia (incidence, treatment, predictors, impact on outcome) and long term follow-up (recent evidences suggest that there may be a non-negligible proportion of poor grade subarachnoid hemorrhage patients who may benefit from substantial improvement at long-term (after 6-12 months of follow-up).