Effects of Mirror Therapy in Patients with Chronic Somatoform Pain Disorders on Psychometric Parameters and Heart Rate Variability

Abstract

Patients with chronic somatoform pain disorders often report impaired quality of life and high symptom burden, often responding inadequately to available treatment options. Mirror therapy has been shown to be effective in treating phantom limb pain following limb amputation and has been used successfully for other disorders, such as complex regional pain syndrome (CRPS). This pilot study examined the efficacy of mirror therapy in patients with chronic somatoform pain disorder, specifically whether and to what extent it can reduce symptom severity and modulate associated autonomic dysregulation. Fifteen patients (n = 15) diagnosed with a chronic somatoform pain disorder (F45.40, F45.41) were enrolled in the study and received four weeks of tablet-based mirror therapy including exercises for the upper and lower limb. Symptom severity was assessed with established questionnaires. In addition, heart rate variability (HRV) was recorded. After mirror therapy, there was a significant reduction in pain intensity (z = -2.878, p = .004). In addition, a reduction in absolute power in the low- frequency band of HRV (t(13) = 2.536, p = .025) was also found. The present pilot study was the first to examine the effect of mirror therapy in individuals with chronic somatoform pain disorders. The results suggest that this intervention may reduce pain intensity and influence associated dysfunctional HRV. Because this is a pilot study, these results and their explanatory power are limited by several factors, such as a small sample size and lack of a control group. Nevertheless, these promising results should be validated in further studies to pave the way for this new additional therapeutic option for these patients.