Somatosensory High Frequency Oscillations reflect clinical fluctuations in migraine

Objective: It has been demonstrated that the early part of 600. Hz High Frequency Oscillations (HFOs), probably generated in the terminal part of thalamo-cortical somatosensory radiations, are abnormally reduced between attacks in migraineurs. We aimed at verifying whether spontaneous clinical fluctuations in migraine are correlated to HFO changes. Methods: We recorded somatosensory evoked potentials in 28 migraine patients. Clinical fluctuations (number of attacks in the 6. months preceding and following the test) were correlated to the HFOs' amplitudes. Moreover, eight out of 28 patients underwent a longer follow-up, including HFO control and clinical observation during the 12. months following the baseline recording. Results: The amplitude of early presynaptic HFOs was significantly correlated to the clinical evolution, since spontaneous worsening was associated with reduced presynaptic HFOs, whereas spontaneous improvement was associated with enhanced presynaptic HFOs (correlation test, p