The frequency and severity of persisting neuropsychological deficits after aneurysmal subarachnoid haemorrhage and associated surgical repair of the aneurysm are all too well known.1 What is less clear is the relative contribution of the initial bleed, widely assumed to be the most salient component in determination of cognitive outcome, versus factors associated with surgical and perioperative management. The Johns Hopkins group (this issue, pp 608–615) have evaluated cognitive outcome after surgical repair of ruptured (n=27) and unruptured (n=20) aneurysms in an attempt at partialling out the contribution of the subarachnoid haemorrhage from the appropriate neurosurgical intervention.2 Albeit in a relatively small series, patients with both ruptured and unruptured aneurysms performed, as a …