Angiogram negative subarachnoid hemorrhage in the setting of sexual intercourse and chronic cannabis use

Etiology of unprovoked subarachnoid hemorrhage (SAH) is predominantly from cerebral aneurysm rupture and manifests classically as a thunderclap headache. Orgasmic cephalgia may herald SAH given that 4-12% of SAH sufferers were found to have engaged in prior sexual activity. Precipitating causes of SAH leading to aneurysmal rupture may be the rise in blood pressure caused by physical activity. A CT angiogram (CTA) is used to reveal a source of the bleed but occasionally this is normal, and is labelled angiogramnegative SAH or non-aneurysmal SAH. In those cases digital subtraction imaging (DSA, conventional angiogram) is needed for verification. Herein we discuss an instance of angiogram negative SAH which occurred after sexual activity in a young male with a chronic cannabis habit.