Increased cerebrovascular pCO2 reactivity in migraine with aura--a transcranial Doppler study during hyperventilation.
Cerebrovascular reactivity during hypocapnia was tested in 20 migraineurs (8 with aura, 12 without aura) and 30 sex- and age-matched healthy subjects, and during nitroglycerin-induced headache in 12 healthy subjects. Before and during hyperventilation, mean blood-flow velocity (Vmean) in the middle cerebral artery was measured with transcranial Doppler. In each subject a pCO2 reactivity index (RI) was calculated as (delta Vmean/baseline Vmean)/delta pCO2. Interictally, patients with migraine with aura showed higher RI (p < 0.05 ANOVA and multiple range test) than controls, whereas migraineurs without aura did not differ from healthy subjects. Ictal and interictal RIs were similar in 9 patients suffering from migraine without aura. No side-to-side differences were detected in RI. During nitroglycerin-induced headache, the RIs were no different from those recorded during migraine attacks and in non-nitroglycerin-provoked healthy controls (p > 0.05, ANOVA and multiple range test). The exaggerated response in migraine with aura might predispose for the characteristic changes in rCBF seen during attacks.
Thomsen
L L
LL
Department of Neurology, Glostrup Hospital, University Hospital of Copenhagen, Denmark.
Iversen
H K
HK
Olesen
J
J
D000328:Adult; D000704:Analysis of Variance; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D006985:Hyperventilation / Q000503:physiopathology*; D016857:Hypocapnia / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000503:physiopathology*; D017585:Ultrasonography, Doppler, Transcranial