Hemicrania continua responsive to botulinum toxin type a: a case report.

BACKGROUND: Hemicrania continua (HC) is a primary headache disorder with full response to indomethacin as one of its diagnostic criteria; however, indomethacin's side effects could limit its use in HC. CASE RESULT: We report a 33-year-old lady whose headache fulfilled the criteria for HC, but the patient developed gastric side effect to indomethacin and did not respond to other pharmacological treatments; however, injecting botulinum toxin type A has led to complete resolution of all of her symptoms. DISCUSSION: We hypothesize the mechanism by which botulinum toxin type A has led to our results through reviewing recent functional neuroimaging findings used to understand the pathophysiology of different primary headache disorders.