EEG Correlates of Self-Managed Neurofeedback Treatment of Central Neuropathic Pain in Chronic Spinal Cord Injury

Abstract

Background Neurofeedback (NFB) is a neuromodulatory technique that enables voluntary modulation of brain activity in order to treat neurological condition, such as central neuropathic pain (CNP). A distinctive feature of this technique is that it actively involves participants in the therapy. In this feasibility study, we present results of participant self-managed NFB treatment of CNP. Methods Fifteen chronic spinal cord injured (SCI) participants (13M, 2F), with chronic CNP equal or greater than 4 on the Visual Numeric Scale, took part in the study. After initial training in hospital (up to 4 sessions), they practiced NF at home, on average 2–3 times a week, over a period of several weeks (min 4, max 20). The NFB protocol consisted of upregulating the alpha (9–12 Hz) and downregulating the theta (4–8 Hz) and the higher beta band (20–30 Hz) power from electrode location C4, for 30 min. The output measures were pain before and after NFB, EEG before and during NFB and pain questionnaires. We analyzed EEG results and show NFB strategies based on the Power Spectrum Density of each single participant. Results Twelve participants achieved statistically significant reduction in pain and in eight participants this reduction was clinically significant (larger than 30%). The most successfully regulated frequency band during NFB was alpha. However, most participants upregulated their individual alpha band, that had an average dominant frequency at α p = 7.6 ± 0.8 Hz (median 8 Hz) that is lower than the average of the general population, which is around 10 Hz. Ten out of fifteen participants significantly upregulated their individual alpha power (α p ± 2 Hz) as compared to 4 participants who upregulated the power in the fixed alpha band (8–12 Hz). Eight out of the twelve participants who achieved a significant reduction of pain, significantly upregulated their individual alpha band power. There was a significantly larger increase in alpha power ( p < 0.0001) and decrease of theta power ( p < 0.04) in participant specific rather than in fixed frequency bands. Conclusion Neurofeedback is a neuromodulatory technique that gives participants control over their pain and can be self-administered at home. Regulation of individual frequency band was related to a significant reduction in pain.

Self-Regulation of SMR Power Led to an Enhancement of Functional Connectivity of Somatomotor Cortices in Fibromyalgia Patients

“…Sensorimotor rhythm (SMR) refers to oscillations between 12 and 15 Hz recorded over somatosensory and motor areas (Pfurtscheller and Lopes da Silva, 1999;Budzynski, 2009;Gruzelier, 2014). Studies about SMR-based neurofeedback training in chronic pain patients have shown significant short-term improvements in pain relief, and other non-pain associated symptoms in patients with complex regional pain syndrome (Jensen et al, 2007), chronic low back pain (Mayaud et al, 2019) and chronic spinal cord injury (Vučković et al, 2019). Furthermore, SMR-based neurofeedback training has provided evidence that it is able to reduce pain and fatigue symptoms in patients with fibromyalgia (Kayıran et al, 2010;Caro and Winter, 2011).…”

EEG alpha activity increased in response to transcutaneous electrical nervous stimulation in young healthy subjects but not in the healthy elderly

“…These findings are in accordance with the literature. Previous studies investigated the pain-related EEG responses and brains' electrical activity during in response to changing of somatosensory stimulus intensity (Chen & Rappelsberger, 1994;Chang et al, 2003;Babiloni et al, 2006;Dowman, Rissacher & Schuckers, 2008;Egsgaard, Wang & Arendt-Nielsen, 2009;Nir et al, 2012;Tiemann et al, 2015;Li et al, 2016;Misra et al, 2017;Wang et al, 2019;Vuckovic et al, 2019). The effect of TENS which was somatosensory stimulus changes according to the intensity of the electrical stimulus (low/high-intensity stimulation) Robb et al, 2008).…”

“…The effect of TENS which was somatosensory stimulus changes according to the intensity of the electrical stimulus (low/high-intensity stimulation) Robb et al, 2008). Most of these studies reported that especially alpha frequency was influenced to changing of the intensity of pain perception (Le Pera et al, 2000;Chang et al, 2001Chang et al, , 2003Babiloni et al, 2006;Egsgaard, Wang & Arendt-Nielsen, 2009;Tiemann et al, 2015;Li et al, 2016;Tu et al, 2016;Wang et al, 2019;Vuckovic et al, 2019). Previous studies suggested that alpha activity was associated with various sensory functions and was influenced by sensorial stimulation (Le Pera et al, 2000;Başar, 2012).…”

“…In the literature, there are many studies which investigated the pain-related EEG responses and brains' electrical activity during the modulation of pain by changes in stimulus intensity (e.g., low intensity and/or high-intensity stimuli) (Chen & Rappelsberger, 1994;Chang et al, 2003;Babiloni et al, 2006;Dowman, Rissacher & Schuckers, 2008;Egsgaard, Wang & Arendt-Nielsen, 2009;Nir et al, 2012;Tiemann et al, 2015;Li et al, 2016;Misra et al, 2017;Wang et al, 2019;Vuckovic et al, 2019). Most of these studies demonstrated that mainly alpha frequency was (alpha power) related to the intensity of pain perception (Le Pera et al, 2000;Chang et al, 2001Chang et al, , 2003Babiloni et al, 2006;Egsgaard, Wang & Arendt-Nielsen, 2009;Tiemann et al, 2015;Li et al, 2016;Tu et al, 2016;Wang et al, 2019;Vuckovic et al, 2019). Tiemann et al (2015) applied painful stimulation to the dorsal face of the hand.…”

The Analgesic Effect of Electroencephalographic Neurofeedback for People With Chronic Pain: Protocol for a Systematic Review and Meta-analysis

“…The goal of EEG neurofeedback is to modulate the targeted maladaptive EEG frequency powers to decrease chronic pain [ 2 , 15 , 16 ]. Surface EEG is recorded from 1 or more electrode sites, depending on the specific pain condition, often from the sensorimotor cortex [ 17 ].…”