Comparing the Impact of Multi-Session Left Dorsolateral Prefrontal and Primary Motor Cortex Neuronavigated Repetitive Transcranial Magnetic Stimulation (nrTMS) on Chronic Pain Patients.

Sascha Freigang,Helmar Bornemann-Cimenti,Annika Eitler,Anže Berlec,Senta Kurschel-Lackner,Bernhard Sutter,Antonio Valentin,Gernot Reishofer,Kariem Mahdy Ali,Hannes Deutschmann,Shane M Fresnoza,Istvan Szilagyi,Elisabeth Hlavka,Michael Mokry,Christian Lehner,Karla Zaar

doi:10.3390/brainsci11080961

Abstract

Repetitive transcranial stimulation (rTMS) has been shown to produce an analgesic effect and therefore has a potential for treating chronic refractory pain. However, previous studies used various stimulation parameters (including cortical targets), and the best stimulation protocol is not yet identified. The present study investigated the effects of multi-session 20 Hz (2000 pulses) and 5 Hz (1800 pulses) rTMS stimulation of left motor cortex (M1-group) and left dorsolateral prefrontal cortex (DLPFC-group), respectively. The M1-group (n = 9) and DLPFC-group (n = 7) completed 13 sessions of neuronavigated stimulation, while a Sham-group (n = 8) completed seven sessions of placebo stimulation. The outcome was measured using the German Pain Questionnaire (GPQ), Depression, Anxiety and Stress Scale (DASS), and SF-12 questionnaire. Pain perception significantly decreased in the DLPFC-group (38.17%) compared to the M1-group (56.11%) (p ≤ 0.001) on the later sessions. Health-related quality of life also improved in the DLPFC-group (40.47) compared to the Sham-group (35.06) (p = 0.016), and mental composite summary (p = 0.001) in the DLPFC-group (49.12) compared to M1-group (39.46). Stimulation of the left DLPFC resulted in pain relief, while M1 stimulation was not effective. Nonetheless, further studies are needed to identify optimal cortical target sites and stimulation parameters.

Highlights

Pain is recently redefined by the International Association for the Study of Pain (IASP)as “an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage” [1]
Reasons included demographic challenges such as a longer commute to the treatment facility and the anticipated difficulty following the specific intervals between experimental sessions
Shapiro–Wilk test indicates that the numerical pain rating scales (NPRS) score (p ≤ 0.001), DASS scores and social function (SF)-12 scores (PCS: p = 0.040, mental composite summary (MCS): p = 0.025) are not normally distributed, all were log-transformed

Summary

Introduction

Pain is recently redefined by the International Association for the Study of Pain (IASP)as “an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage” [1]. Chronic pain is one of the leading causes of years lived with disability (YLDs) and reduced quality of life (QoL). In Europe, high prevalence rates were reported for back/neck (40%), hand/arm (22%), and foot/leg (21%) pain [3]. Over the past 30 years, the prevalence of most diseases showed a pattern of steady decline as measured by age-standardised disability-adjusted life-years (DALYs) rates, chronic low back pain (LBP) remained in the top ten (fourth) causes of DALYs for children and younger adults. Low back pain in childhood predicts low back pain in adult life and is more common in female than male individuals at all ages [4]. As modern medicine extends the population age, it is most likely that the global prevalence of LBP will further increase in the following decades. Research to develop safe and effective interventions is needed to improve health and alleviate the socioeconomic burden of chronic pain patients

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