Cardiac-Gated Neuromodulation Increased Baroreflex Sensitivity and Reduced Pain Sensitivity in Female Fibromyalgia Patients

Abstract

The study presents a novel approach of programing pain inhibition in chronic pain patients based on the hypothesis that pain perception is modulated by dysfunctional dorsal medial nucleus tractus solitarii (dmNTS) reflex arcs that produce diminished baroreflex sensitivity (BRS) resulting from a conditioned response. This study tested whether administration of noxious and non-noxious electrical stimuli synchronized with the cardiac cycle resets BRS, reestablishing pain inhibition. A total of 30 pain-free normotensives controls (NC) and 32 normotensives fibromyalgia (FM) patients received two, ≈8 min-epochs of cardiac-gated, peripheral electrical stimuli. Non-painful and painful electrical stimuli were synchronized to the cardiac cycle as the neuromodulation experimental protocol (EP) with two control conditions (CC1, CC2). BRS, heart-rate-variability (HRV), pain threshold and tolerance, and clinical pain intensity were assessed. Reduced BRS in FM at baseline increased by 41% during two, ≈8 min-epochs of stimulation. Thresholds in FM increased significantly during the experimental protocol (all Ps < 0.001) as did HRV. FM levels of clinical pain significantly decreased by 35.52% during the experimental protocol but not during control stimulations (p < 0.001). Baroreceptor training may reduce FM pain by BRS-mediated effects on intrinsic pain regulatory systems and autonomic responses.

Autonomic nervous system responses in the intermediate band to cranial cutaneous stimulation

“…Stimulation of baroreceptors following increases in BP reach the dorsal medial nucleus of the solitary tract (dmNTS) reflex arcs, which, in turn, modulates BP, heart rate (HR), vascular dilation, autonomic balance, sleep, and pain perception. These physiological pathways have been successfully applied to the treatment of chronic pain in fibromyalgia (Thieme et al., 2022 ).…”

“…Opposing views interpreted cardiovascular rhythms either as “clanking of the cogs” or attributed them to vital functions indexing autonomic nervous system (ANS) activity (Laborde et al., 2017 ; Malpas, 2002 ; Park & Thayer, 2014 ; Pomeranz et al., 1985 ). Few fruits of this vast body of research have made it into clinical care of patients such as cardiac‐gated neuromodulation of baroreflex and pain sensitivity (Thieme et al., 2022 ). Yet there is no doubt today that cardiovascular rhythms represent different functional states of the ANS.…”

“…. Few fruits of this vast body of research have made it into clinical care of patients such as cardiacgated neuromodulation of baroreflex and pain sensitivity (Thieme et al, 2022). Yet there is no doubt today that cardiovascular rhythms represent different functional states of the ANS.…”

Effects of Systolic Extinction Therapy in a Female Patient with Seropositive Rheumatoid Arthritis. A Case Report

“…Individuals with a hypertensive reactivity to prolonged stress may develop permanently increased blood pressure with reduced variability that diminishes activity of arterial baroreceptors located in the carotid sinus [16]. Cardiac-gated baroreceptor training increases blood pressure variability with resultant activation of the BRS [17] and inhibition of sympathetic cardio motor and vasoconstrictor neurons by reactivation of NTS reflex arcs responsible for the regulation of blood pressure, pain, anxiety and sleep [6]. For SET adherence was assessed by completion of homework assignments.…”

Autonomic responses to aerobic and resistance exercise in patients with chronic musculoskeletal pain: A systematic review

“…Significant correlations between chronic neck-shoulder pain and autonomic dysfunction [ 15 ]. Patients with fibromyalgia also tend to exhibit autonomic dysregulation [ 16 ]. Furthermore, a recent article focused on patients with osteoarthritis and autonomic function [ 17 ].…”