Table 2 shows information on the clinical course and the treatment performed in patients of both study groups. Acute hydrocephalus requiring CSF diversion was associated with neuropsychological morbidity after discharge (p = 0.009). Aneurysm occlusion was performed within 72 h after haemorrhage, whenever feasible. A total of 58 aneurysms were clipped and 36 aneurysms were occluded using endovascular techniques (including 34 coiling procedures; one stent-assisted coiling and one aneurysm was primarily stented). Patients without NPD were distributed equally between the two modalities of aneurysm therapy (p = 0.706). No patient with regular neuropsychological outcome required shunt surgery for chronic hydrocephalus (p = 0.019). Two of 12 patients who required decompressive hemicraniectomy (DHC) for elevated intracranial pressure (ICP) refractory to maximal conservative therapy showed no NPD at the follow-up (p = 0.590). Patients without NPD showed a tendency towards a lower rate of CVS (12.5 vs. 45.2 %; p = 0.131) and none developed DCI (0 vs. 33.3 %; p = 0.100). Patients with regular neuropsychological outcome were discharged significantly earlier than patients with cognitive constraint (p < 0.001).