Ergotamine, flunarizine and sumatriptan do not change cerebral blood flow velocity in normal subjects and migraneurs

Abstract

Changes in the diameter of extracranial and intracranial arteries resulting in changes in cerebral blood flow have previously been assumed to be the most important pathophysiological factor in migraine. To test this hypothesis 20 normal subjects, and three groups of patients (n = 29) with migraine were investigated by means of transcranial Doppler sonography. Blood flow velocities in the middle cerebral (MCA) and in basilar (BA) arteries were measured. Data from patients were obtained in the interval between migraine attacks, during migraine attacks and following treatment with either ergotamine (0.5 mg i.m.; n = 10); flunarizine, a calcium overload blocker (20 mg i.v.; n = 13); or a 5-HT1-like agonist (sumatriptan, 4 mg s.c.; n = 6). Ergotamine and sumatriptan are constrictors of cerebral arteries in animal experiments. The arithmetic mean of flow velocity in the BA was reduced in normal subjects (45 cm/s) as compared with patients with migraine measured in between attacks (53 cm/s). Mean flow velocity in MCA was not different in normals (72.5 cm/s) as compared with migraineurs (75 cm/s). Neither ergotamine nor the 5-HT1 agonist and flunarizine resulted in a significant change in blood flow velocity in MCA and BA. This was true irrespective of whether the drugs were given in the headache-free period, during a migraine attack or during the withdrawal phase of drug-induced headache. Ergotamine was effective in improving headache during migraine attacks and sumatriptan attenuated headache during drug withdrawal from chronic analgesic intake. These results indicate that the action of ergotamine and the 5-HT1-receptor agonist is probably not mediated by their vasoconstrictor action on cerebral arteries.