P363 Neurophysiologic alterations and effects of DRD2 gene polymorphism in burning mouth syndrome

Background and aims Neuropathic mechanisms are involved in burning mouth syndrome (BMS), and variation of dopamine D2 receptor (DRD2) gene may contribute to pain perception. We investigated whether the neurophysiologic findings differ in BMS patients compared with healthy controls, and whether 957C u003e T polymorphism of the DRD2 gene influences perception or interference of pain in daily life in BMS. Methods 45 BMS patients (43 women, mean age 62.5 years) and 32 healthy controls (30 women, mean age 64.8 years) participated. Patients estimated pain intensity, suffering, quality of life (QoL) and sleep with NRS. Blink reflex (BR) of the supraorbital (SON), mental (MN) and lingual (LN) nerves and thermal quantitative sensory testing were done. The results were analysed with ANOVA. DRD2 gene 957C u003e T polymorphism was determined in 31 patients and its effects on neurophysiologic and clinical variables analysed. Results Cool ( p  = 0.0090) and warm detection thresholds ( p  = 0.0229) were higher in BMS patients than controls. The stimulation threshold for SON BR was higher in patients than in controls ( p  = 0.0056). The latencies of R2 component were longer in BMS patients than in controls ( p  = 0.0005) at the SON distribution. Habituation of SON BR did not differ between the groups. The heat pain thresholds were highest ( p p  = 0.0254–0.0352). Conclusions Thepatients showed thermal hypoesthesia within LN distribution compatible with small fibre neuropathy in BMS. The DRD2 957 C u003e T genotype may influence perception and interference of pain in BMS.