Nimodipine for treatment of primary thunderclap headache.

Eleven patients with primary thunderclap headache (TCH) were treated with oral nimodipine 30 to 60 mg every 4 hours or IV nimodipine 0.5 to 2 mg/h if the oral regimen failed or images showed cerebral vasospasm. With oral nimodipine, headache did not recur in the nine patients without vasospasm. IV nimodipine was given in two patients with vasospasm, including one who developed ischemic stroke. Nimodipine may be effective for TCH. Vasospasm may warrant IV nimodipine.