fNIRS measurements in migraine

Migraine is a complex chronic neurovascular disorder in which the interictal changes in neuronal excitability and vascular reactivity in the cerebral cortex were detected. The extent and direction of the changes in cerebral blood flow that affect cerebral hemodynamics during attacks, however, are still a matter of debate. This may have been due to the logistic and technical problems posed by the different techniques to determine cerebral blood flow during migraine attacks and the different definitions of patient populations. In this study, we have investigated hypercapnia challenges by breath holding task on subjects with and without migraine by using functional near infrared spectroscopy (fNIRS). Measurements of the relative changes in concentration of deoxy-hemoglobin [Hb] and oxy-hemoglobin [HbO2] are performed on four healthy subjects during three breath holdings of 30 seconds (s.) interleaved with 90 s. of normal breathing. We have observed [Hb]increase during breath holding interval in subject without migraine whereas in subject with migraine [Hb] decreases during breath holding interval. The result of our study suggest that hypercapnia effect on cerebral hemodynamic of subject with migraine and without migraine could be due to different vascular reactivity to PCO2 (carbon dioxide partial pressure) in arteries.