Myogenic cerebrovascular autoregulation in migraine measured by stress transcranial Doppler sonography

Transcranial Doppler sonography (TCD) studies may help to elucidate the nature and role of vascular abnormalities in migraine. Our aim in this study was to evaluate cerebrovascular autoregulative response in migraine patients with and without aura to blood pressure increase using stress TCD.

Using transcranial Doppler ultrasound at rest and during ergometer stress (stress TCD), we studied the changes in mean flow velocities and resistance index (RI) in relation to physical stress in the middle cerebral artery. Fifteen migraine patients without aura, 15 migraine patients with aura, and 15 healthy control subjects were examined. Patients suffered from predominantly unilateral headache and were studied during an attack-free period. The Pourcelot's RI as a measure of cerebrovascular reactivity was calculated by dividing the difference between systolic and diastolic velocity by the systolic velocity.

None of the subgroups showed any difference during ergometer exercise with regard to blood pressure, endtidal CO2, heart rate, or mean flow velocity. In all subgroups, sufficient physical stress was achieved. With respect to RI change, migraine patients without aura and healthy controls did not differ (p > 0.05). However, the RI change of migraine patients with aura was significantly lower than the RI change of migraine patients without aura or healthy subjects (p > 0.05). The discrimination analysis showed in addition that RI change (absolute and as a percentage) and mean flow velocity change (as a percentage) could be used as diagnostic variables to detect patients with aura symptoms.

Differences exist in cerebrovascular reactivity in migraine patients with aura that may contribute to the neurologic disturbances in these patients during attack. We propose that there is disorder of myogenic cerebrovascular autoregulation in migraine patients with aura during headache-free intervals.