Changes in cerebral vascular reactivity in transcranial Doppler for migraine without aura

The cerebrovascular reactivity was measured by means of transcranial Doppler in 40 patients with migraine without aura during the headache-free interval and in 40 healthy controls. The vasomotor response Mas evaluated during hypercapnia induced by inhalation of a mixture of CO2 5% and O-2 95% and during hypocapnia obtained after voluntary hyperventilation. The reactivity index values during CO2 inhalation were reduced in migraine patients with respect to controls (P=0.0001), while values obtained during hypocapnia did not differ between migraine patients and controls (P=0.3). Our data suggest a reduced vasodilatory response to hypercapnia of cerebral arterioles in patients suffering from migraine without aura with respect to controls that might be related to the presence of a baseline arteriolar vasodilation.