Trigeminal somatosensorial evoked potentials suggest increased excitability during interictal period in patients with long disease duration in migraine

Abstract

Introduction: Migraine pathogenesis is suggested to involve many structures in cerebral cortex, brainstem and trigeminovascular system. Electrophysiological studies revealed loss of habituation, decreased cortical preactivation, segmental hypersensitivity and reduction in control of inhibitory descending pathways. Given these information, we aimed to evaluate the excitability changes of the trigeminal pathway in the cortex and brainstem in migraine using trigeminal nerve somatosensory evoked potentials (TSEP).

Patients and method: Fifty-one women with migraine without aura and 32 age-matched healthy women were included. TSEPs were recorded in migraine patients during interictal period and in healthy subjects. Sensory thresholds, stimulation intensities, latencies of N1, P1, N2 and P2 waves as well as N1/P1 and N2/P1 amplitudes were measured.

Results: Comparisons of ipsilateral latencies with N1-P1 and N2-P1 amplitudes between migraine and control groups showed no difference. Sensory thresholds were also similar. Stimulation thresholds decreased as the attack frequency increased and ipsilateral N1/P1 amplitude increased with prolonged disease duration (p=0.043).

Conclusion: Our study did not show significant difference between migraine patients and healthy subjects during interictal period. However, migraine with long duration affects the excitability of the cortical and brainstem trigeminal pathways even during interictal periods.

Keywords: Migraine; Trigeminal nerve sensory evoked potentials; Trigeminal pathway.