aSDH from rupture of an aneurysm was first reported by Hasse in 1855.111 The reported incidence in autopsy studies (10 - 22%) is higher than in clinical studies (0.5 - 1.6%) owing to the high rate of mortality associated with this condition.
In almost all reported series of aSDH caused by aneurysm, the most common aneurysm arises in the posterior communicating artery followed by the MCA.
Different mechanisms have been proposed to explain the occurrence of an aSDH after a ruptured aneurysm.
The initial management dilemma lies in differentiating an aneurysmal aSDH from a traumatic SDH.
The subsequent management dilemmas involve the decision to perform a diagnostic angiogram prior to craniotomy in poor-grade patients where the aSDH is causing a significant mass effect.
The advantages are that the risk of re-bleeding following drainage of an aSDH can be avoided and the patient is spared the trauma of a two-stage procedure.