Functional Magnetic Resonance Imaging Evaluation of Auricular Percutaneous Electrical Neural Field Stimulation for Fibromyalgia: Protocol for a Feasibility Study

Abstract

BackgroundFibromyalgia is a chronic pain state that includes widespread musculoskeletal pain, fatigue, psychiatric symptoms, cognitive and sleep disturbances, and multiple somatic symptoms. Current therapies are often insufficient or come with significant risks, and while there is an increasing demand for non-pharmacologic and especially non-opioid pain management such as that offered through complementary and alternative medicine therapies, there is currently insufficient evidence to recommend these therapies. Percutaneous electrical neural stimulation (PENS) is an evidence-based treatment option for pain conditions that involves electrical current stimulation through needles inserted into the skin. Percutaneous electrical neural field stimulation (PENFS) of the auricle is similar to PENS, but instead of targeting a single neurovascular bundle, PENFS stimulates the entire ear, covering all auricular branches of the cranial nerves, including the vagus nerve. The neural mechanisms of PENFS for fibromyalgia symptom relief are unknown.ObjectiveWe hypothesize that PENFS treatment will decrease functional brain connectivity between the default mode network (DMN) and right posterior insula in fibromyalgia patients. We expect that the decrease in functional connectivity between the DMN and insula will correlate with patient-reported analgesic improvements as indicated by the Defense and Veterans Pain Rating Scale (DVPRS) and will be anti-correlated with patient-reported analgesic medication consumption. Exploratory analyses will be performed for further hypothesis generation.MethodsA total of 20 adults from the Atlanta Veterans Affairs Medical Center diagnosed with fibromyalgia will be randomized into 2 groups: 10 subjects to a control (standard therapy) group and 10 subjects to a PENFS treatment group. The pragmatic, standard therapy group will include pharmacologic treatments such as anticonvulsants, non-steroidal anti-inflammatory drugs, topical agents and physical therapy individualized to patient comorbidities and preferences, prescribed by a pain management practitioner. The PENFS group will include the above therapies in addition to the PENFS treatments. The PENFS subject group will have the Neuro-Stim System placed on the ear for 5 days then removed and replaced once per week for 4 weeks. The primary outcome will be resting functional magnetic resonance imaging connectivity between DMN and insula, which will also be correlated with pain relief and functional improvements. This connectivity will be analyzed utilizing functional connectivity magnetic resonance imaging (fcMRI) and will be compared with patient-reported analgesic improvements as indicated by the DVPRS and patient-reported analgesic medication consumption. Pain and function will be further evaluated using Patient-Reported Outcomes Measurement Information System measures and measures describing a person’s functional status from Activity and Participation section of the International Classification of Functioning Disability and Health.ResultsThis trial...

The Impact of Auricular Vagus Nerve Stimulation on Pain and Life Quality in Patients with Fibromyalgia Syndrome

“…The assessment methods are implemented two weeks prior to treatment commences and two weeks after the treatment is completed. This study began in 2017 and is ongoing [30].…”

Percutaneous electric nerve field stimulation alters cortical thickness in a pilot study of veterans with fibromyalgia

“…This procedure was completed weekly over 4 weeks and is further described in prior publications. ( Woodbury et al, 2020 , Gebre et al, 2018 ).…”

“…Methods pertaining to participant screening and recruitment, magnetic resonance imaging (MRI) acquisition, randomization, intervention, behavioral outcome measures and follow-up are further detailed in our prior publications related to evaluation of resting state functional connectivity MRI (rs-fcMRI) in treatment of fibromyalgia with PENFS (Military Field Stimulator©, Innovative Health Solutions, Versailles, IN, USA). ( Woodbury et al, 2020 , Gebre et al, 2018 ) Participants were allowed to use standard therapy based on individual preferences, comorbidities, and recommendations from their clinical care provider. To control for the influence of weekly visits in the PENFS group, participants in the ST only group were also provided weekly visits with medication increases as needed for pain during their 4-week study treatment period.…”

“…A 3x3x3 cm GABA voxel was placed in the r-pIns in each subject for MRS acquisition with concurrent structural and rs-fcMRI acquisition. ( Gebre et al, 2018 ).…”

Feasibility of Auricular Field Stimulation in Fibromyalgia: Evaluation by Functional Magnetic Resonance Imaging, Randomized Trial

“…One nonpharmacologic method for modulating autonomic nervous system dysregulation and treating pain is vagal nerve stimulation (VNS), which can be performed using the ear [7,8]. The neuro-stim system (NSS) is a device approved by the Food and Drug Administration (FDA) for pain that targets the auricular branches of several cranial nerves, including the vagus via percutaneous electrical neural field stimulation (PENFS) [9,10], providing a nonpharmacologic alternative for pain treatment.…”