ABSTRACT
Migraine pain is considered to manifest itself as a result of an impaired cerebrovascular reactivity. Hence, proper quantification and diagnosis of this problem without causing more disturbance has always been a challenge in investigating migraine pathogenesis. Functional near-infrared spectroscopy system (fNIRS) is being proposed as an inexpensive, rapid, safe and accurate technique to monitor cerebrovascular dynamics. We have developed NIROXCOPE 201, a novel multi source and detector device of fNIRS, and attempted to investigate the cerebrovascular reactivity of migraine patients to a breath hold task which produces a metabolic perturbation. Six normals and six migraine patients performed four consecutive breath holding task. A typical brain hemodynamic response (BHR) is observed both for controls and migraineurs with an initial phase, main response and a recovery phase. Hence, fitting to a sum of three sequentially arranged gaussian curves proved that amplitudes of [Hb] and [HbO2] signals acquired by fNIRS are approximately two to five times higher in controls than migraine patients (P<0.01) for all phases. Moreover, amplitude change between successive breath holds tends to converge to a steady value for controls whereas an uncontrolled percent change is observed for migraineurs. Our results confirm an impaired cerebrovascular reactivity in the frontal cortex of migraine patients interictally.
Subject(s)
Cerebrovascular Circulation/physiology , Hypercapnia/diagnosis , Migraine without Aura/diagnosis , Migraine without Aura/physiopathology , Spectroscopy, Near-Infrared , Adult , Female , Hemodynamics/physiology , Hemoglobins/metabolism , Humans , Hypercapnia/complications , Male , Migraine without Aura/etiology , Nonlinear Dynamics , Oxyhemoglobins/metabolismABSTRACT
Migraine is hypothesized to be a neurovascular coupling disorder where the cerebral vascular reactivity is malfunctioning and measuring hemodynamic changes during migraine without causing more disturbance has always been a challenge. Functional near infrared spectroscopy system (fNIRS) is being proposed as an inexpensive, rapid, safe and accurate alternative to fMRI, transcranial doppler sonography (TCD). We have developed NIROXCOPE 201, a novel device for fNIRS which offers 16 source-detector pairs distributed on a probe that is placed on the forehead. Measuring hemodynamic changes during migraine without causing more disturbance has always been a challenge. Using NIROXCOPE 201, we have attempted to investigate the cerebrovascular reactivity of migraine patients to a breath hold task which produces a metabolic perturbation. Six normals and six migraine patients performed four consecutive breath holding task. We calculated the peak and latencies of the initial dip and recovery phases for [Hb], [HbO(2)], [tHb], and [OXY] signals. [Hb], [tHb], and [OXY] ID and R amplitudes of normals are approximately a magnitude higher than migraine patients (P<0.01), while latencies showed no significant differences. Data suggests an altered neurovascular coupling in frontal cortex of migraine patients interictally. The application of NIROXCOPE 201 to patients suffering from other primary headache disorders will reveal diagnostic as well as therapeutic implications of the presented study.
