Anxiety and sympathetic skin responses in patients with masticatory muscle pain

Abstract

Background: An important clinical aspect of masticatory muscle pain is its association with autonomic disorders and various mental states. Sympathetic skin response is a non-invasive approach for assessing sympathetic system function, allowing the determination of several autonomic indices (amplitudes), but their clinical interpretation is difficult. The aim of the study was to differentiate variants of sympathetic skin response and their correlations with the level of anxiety and pain intensity in patients with masticatory muscle pain. Material and methods: There were enrolled 46 patients with masticatory muscle pain who were examined in standardized conditions with NeuroMEP (Neurosoft) for assessing sympathetic skin responses (SSR) – sympathetic amplitude (A2). There were used cutoffs for different SSR variants: 1) V1 – optimal A2 = 3.34 – 3.5 mV; 2) V2 – amplified A2 ≥ 3.51 mV; 3) V3 – diminished A2 ≤ 3.33 mV. There were used clinical indices: GAD7 questionnaire (anxiety level), CPI index (Characteristic Pain Intensity). Results: There were observed the following variants in patients with masticatory muscle pain: V1 – 16 patients (34.78%); V2 – 25 patients (54.35%); V3 – 5 patients (10.87%). Patients with V2 variant had higher levels of anxiety (mean GAD7 score = 17.1): 1) severe anxiety – 17 patients (68%); 2) moderate anxiety – 7 patients (28%); 3) low anxiety – 1 patient (4%). V2 variant patients also had higher mean CPI values (54.1 – high intensity pain). Conclusions: There were observed different variants of sympathetic response in patients with masticatory muscle pain, the amplified variant correlated with more serious clinical indices (higher anxiety and pain intensity).