To characterize autonomic imbalance in migraine, we compared the cardiovascular reflex responses of 10 migraineurs and 10 healthy subjects after pharmacological noradrenergic stimulation or inhibition. A battery of 5 autonomic tests was administered on basal conditions as well as after pretreatment with drugs acting at different levels on the noradrenergic pathway: pseudoephedrine, clonidine, guanethidine, indenolol, prazosin. Our data confirm a predominantly sympathetic hypofunction in migraine and provide evidence for an impairment of the central autonomic control.