A nonrandomized study not included in the meta-analysis com- pared 95 patients who underwent aneurysm clipping, cisternal blood evacuation, and lamina terminalis fenestration with 28 comparable, non blood-cleansed, endovascular therapy treated patients and found that shunt-dependent hydrocepha- lus occurred in 17% of surgical patients versus 33% of patients treated with endovascular therapy (statistical signif- icance not reported).237 Management of Hydrocephalus Associated With aSAH: Recommendations 1. aSAH-associated acute symptomatic hydrocephalus should be managed by cerebrospinal fluid diversion (EVD or lumbar drainage, depending on the clinical scenario) (Class I; Level of Evidence B). (Revised recommendation from previous guidelines) 2. aSAH-associated chronic symptomatic hydrocepha- lus should be treated with permanent cerebrospinal fluid diversion (Class I; Level of Evidence C). (Re- vised recommendation from previous guidelines) 3. Weaning EVD over >24 hours does not appear to be effective in reducing the need for ventricular shunt- ing (Class III; Level of Evidence B). (New recommendation) 4. Routine fenestration of the lamina terminalis is not useful for reducing the rate of shunt-dependent hydrocephalus and therefore should not be routinely Connolly et al Management of Aneurysmal Subarachnoid Hemorrhage 1725 performed. (Class III; Level of Evidence B). (New recommendation) Management of Seizures Associated With aSAH The incidence, future implications, and management of sei- zures associated with aSAH are controversial. At present, no randomized, controlled trials are available to guide decisions on prophylaxis or treatment of seizures.2,272 A relatively high percentage of aSAH patients (as many as 26%) experience seizure-like episodes,99,272,273 but it remains unclear whether these episodes are verifiably epileptic in origin.99,274 More recent retrospective reviews suggest a lower seizure inci- dence of 6% to 18%,275 278 and 2 of these studies276,278 found that the majority of such patients reported onset of seizure occurring before medical evaluation. 