Impact of the lunar cycle on the incidence of intracranial aneurysm rupture: Myth or reality?

Objective To analyze the impact of the lunar cycle and season on the incidence of aneurysmal subarachnoid hemorrhage (SAH). Patients and methods The medical records of 111 patients who were admitted over a 5-year period to our department because of aneurysmal SAH were retrospectively reviewed. The date of aneurysm rupture was matched with the corresponding season and moon phase. Results An incidence peak for aneurysm rupture (28 patients) was seen during the phase of new moon, which was statistically significant (p < 0.001). In contrast, no seasonal variation in the incidence of SAH was observed. Conclusion The lunar cycle seems to affect the incidence of intracranial aneurysm rupture, with the new moon being associated with an increased risk of aneurysmal SAH.