O041. GRIA3 (glutamate receptor, ionotropic, ampa 3) gene polymorphism influences cortical response to somatosensory stimulation in medication-overuse headache (MOH) patients

Abstract

Medication-overuse headache (MOH) is a secondary form of chronic headache developed by migraineurs after prolonged symptomatic medication overuse. Bio-behavioural sensitization is a key mechanism in MOH pathophysiology, as evidenced by cortical somatosensory evoked potentials (SSEPs) studies. While episodic migraineurs, recorded between attacks, showed lower initial SSEP amplitudes and lack of habitation during stimulus repetition, in MOH patients the SSEPs were initially higher and further increased during stimulus repetition, resulting in a persistent sensitisation proportional to the duration of the headache chronification phase. The central sensitization seems to be strongly dependent by glutamate. Amongst various gene polymorphisms in the glutamatergic system, only the Glutamate Receptor Ionotropic AMPA 3 (GRIA3) was previously associated with migraine. The aim of our study was to verify whether GRIA3 rs3761555 single nucleotide polymorphism (SNP) could influence processes of central sensitization of MOH patients.