The analgesic effect of electroencephalographic neurofeedback for people with chronic pain: A systematic review and meta‐analysis

Abstract

Background Electroencephalographic (EEG) neurofeedback has been utilized to regulate abnormal brain activity associated with chronic pain. Methods In this systematic review, we synthesized the evidence from randomized controlled trials (RCTs) to evaluate the effect of EEG neurofeedback on chronic pain using random effects meta‐analyses. Additionally, we performed a narrative review to explore the results of non‐randomized studies. The quality of included studies was assessed using Cochrane risk of bias tools, and the GRADE system was used to rate the certainty of evidence. Results Ten RCTs and 13 non‐randomized studies were included. The primary meta‐analysis on nine eligible RCTs indicated that although there is low confidence, EEG neurofeedback may have a clinically meaningful effect on pain intensity in short‐term. Removing the studies with high risk of bias from the primary meta‐analysis resulted in moderate confidence that there remained a clinically meaningful effect on pain intensity. We could not draw any conclusion from the findings of non‐randomized studies, as they were mostly non‐comparative trials or explorative case series. However, the extracted data indicated that the neurofeedback protocols in both RCTs and non‐randomized studies mainly involved the conventional EEG neurofeedback approach, which targeted reinforcing either alpha or sensorimotor rhythms and suppressing theta and/or beta bands on one brain region at a time. A posthoc analysis of RCTs utilizing the conventional approach resulted in a clinically meaningful effect estimate for pain intensity. Conclusion Although there is promising evidence on the analgesic effect of EEG neurofeedback, further studies with larger sample sizes and higher quality of evidence are required.

Infraslow Neurofeedback Training Alters Effective Connectivity in Individuals with Chronic Low Back Pain: A Secondary Analysis of a Pilot Randomized Placebo-Controlled Study

“…This study demonstrated a significant effect of ISF-NF up-training pgACC on the effective connectivity when compared to sham-NF training, and furthermore, the amount of information transfer from the pgACC to the S1L was correlated with the amount of pain severity reduction. While only a few previous studies have demonstrated objective neural changes following EEG-NF training [ 9 , 10 , 11 ], our study is the first study to demonstrate evidence of correlations of objective neural changes with improvements in clinical outcomes, thus indicating the specificity of the EEG-NF training.…”

“…To our knowledge, our study is the first double-blinded randomised placebo-controlled trial to explore the effect of EEG ISF-NF on the effective connectivity between the targeted brain regions, and its associations with the changes in clinical outcomes of pain and disability, as these are important and recommended domains for determining the specificity of the EEG-NF training [ 11 ]. This study demonstrated a significant effect of ISF-NF up-training pgACC on the effective connectivity when compared to sham-NF training, and furthermore, the amount of information transfer from the pgACC to the S1L was correlated with the amount of pain severity reduction.…”

“…EEG-NF for retraining the aberrant cortical activity in people with chronic pain has attracted significant interest over the past decade [ 9 , 10 , 11 ]. The reason for this is that neuromodulation techniques that are based on transcranial stimulation, either transcranial magnetic stimulation or transcranial electrical stimulation, merely disrupt activity and connectivity.…”

“…With considerable neuroimaging evidence of cortical activity alterations in individuals with chronic pain [ 2 , 3 , 4 , 5 , 6 , 7 , 8 ], closed-loop NF training has been explored by several non-randomised studies and pilot randomised controlled trials as a potential treatment option for chronic pain conditions (e.g., fibromyalgia, headache, neuropathic pain) [ 9 , 10 , 11 ]. Recent systematic reviews and meta-analyses highlight that, although the confidence is low, the EEG-NF may offer clinically meaningful benefits in short-term pain intensity and pain interference in people with chronic pain [ 9 , 10 , 11 ]. Furthermore, a few studies also demonstrate improvements in pain-associated symptoms (such as depression, anxiety, fatigue, and sleep) [ 12 , 13 , 14 ], which are well-known to have a detrimental effect on ongoing pain, contributing to disability and poor quality of life.…”

The importance of self-efficacy and negative affect for neurofeedback success for central neuropathic pain after a spinal cord injury

“…Similarly, Kayiran et al 8 supressed theta (3–8 Hz) while reinforcing low beta (13–15 Hz) that also resulted in pain reduction. A recent meta-analysis found that neurofeedback based on alpha band upregulation result in clinically meaningful reduction of pain but concluded that more studies are required to confirm the results 9 .…”