Circumstances and precipitating factors preceding intracranial aneurysm rupture: a systematic review

The role of immediate precipitating activities in aneurysmal subarachnoid hemorrhage (aSAH) remains unclear, lcontributing to uncertainty regarding activity restriction. This systematic review and meta-analysis examined the relative strain of activities preceding spontaneous aSAH using metabolic equivalents of task (METs).

A systematic search identified studies reporting activities preceding aSAH (categorised as nonstrenuous, MET 1-4, and strenuous, MET ≥5). Associations between activity category and aSAH occurrence were assessed using chi-squared testing, with Fisher's combined method evaluating overall association. Odds of aSAH were evaluated using sleep or rest (MET 1) as the reference.

Six studies (3,285 aSAH cases) were included. aSAH mostly preceded nonstrenuous activities (43.2%) compared with strenuous activities (23.5%). Heavy strain activities (MET 6-8) , preceded 8.9% of cases ,while Valsalva maneuversaccounted for 7.9%. Fisher's combined method showed aSAH occurred less frequently after strenuous activities (p <0.001). Compared with sleep or rest, odds of aSAH were comparable or lower across all other activity categories.

Routine nonstrenuous activities most often preceded aSAH, suggesting high physical exertion may not be a dominant immediate trigger of aneurysm rupture. Other factors, including circadian blood pressure fluctuations and impaired autoregulation, may contribute to rupture risk.