A rare case of recurrent headache during exercise due to severe intracranial atherosclerotic stenosis.

Intracranial atherosclerotic stenosis (ICAS) can cause ischemic stroke, up to 30-50% stroke in Asian population. However, recurrent exercise-induced headache due to ICAS has not been reported. We present a case of a patient 60-year-old male suffering from recurrent headache during exercise due to severe ICAS. The headache occurred after 5 minutes of running, appeared shortly after every running, and resolved at rest. Head magnetic resonance angiography showed moderate bilateral stenosis at middle cerebral artery (MCA), and cerebral catheter angiography confirmed 70% stenosis of the left MCA and 20% stenosis of the right MCA, with robust antegrade flow and good collaterals which explained why there was no neurological deficit. After treated with best medical therapy, including dual antiplatelet, statin therapy, and risk factor modification, for 90 days, he was capable of running for 20 min without headache.