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GWAS = genome-wide association study; FHM = familial hemiplegic migraine; ICHD1 = International Classification of Headache Disorders, first edition (published in 1988). *Ten studies measured non-neurologic features in cluster headache or migraine, specifically the circadian features of the heart rate, blood pressure, reflexes, epinephrine, sodium, cyproheptadine, or tweets about headaches.
