Subcortical Hyperexcitability in Migraineurs: A High-Frequency Oscillation Study

Abstract

An abnormal central nervous system excitability level was found in patients with migraine. Whether it is hyper- or hypo-excitable is still debated. This study aimed to compare the somatosensory high-frequency oscillations (HFOs), which reflected subcortical excitability (early phase) and intracortical inhibition (late phase), between patients with migraine and control subjects. HFOs were recorded from C3'-Fz, using a 500-1000 Hz frequency filter after stimulation at right median nerves at the wrists, and divided into early and late phases based on the N20 peak. Fifty-nine untreated patients (n=24 during ictal period; n=35, interictal) and 22 controls finished the study. In early HFOs, patients both during ictal and interictal periods had higher maximal amplitudes (p=0.039) and area-under-curve (p=0.029) than those of the controls. Regarding the late HFOs, there were no significant differences among these groups. Our study suggests a hyper-excitable state in the subcortical regions in patients with migraine both during interictal and ictal periods.