A 36-year-old woman presented in the emergency department after experiencing an episode of severe headache with a sudden, explosive onset during sexual intercourse. The headache was associated with nausea, vomiting and photophobia, and persisted for approximately 3 h. The patient reported that she had never experienced such a sudden and intense headache before. The initial CT angiography performed in the emergency room showed severe multisegmental vasoconstriction in the anterior and posterior circulation. There were no signs of subarachnoid haemorrhage (SAH) or arterial dissection. The CSF tap on …