What is the true incidence of sentinel headaches in aneurysmal subarachnoid hemorrhage?
The true incidence of sentinel headaches in aneurysmal subarachnoid hemorrhage is not well established, as there is a lack of comprehensive studies. However, a systematic review by Polmear (2003) suggests that the incidence of sentinel headaches may be between 6-17%, with some studies showing an incidence as high as 25%. Additionally, a study by Beck et al (2006) suggests that the presence of sentinel headache significantly increases the risk of rebleeding after aneurysmal subarachnoid hemorrhage.  