Abstract
Fibromyalgia is a chronic primary pain condition contributing to significant disability worldwide. Neuroimaging studies have identified abnormal effective connectivity between cortical areas responsible for descending pain modulation and sensory components of pain experience [i.e., between pregenual anterior cingulate cortex (pgACC) and primary somatosensory cortex (S1) respectively]. Neurofeedback (NF), a brain-computer interface technique, can normalize dysfunctional brain activity, and thereby improve pain and function. The aim of this double-blinded randomised placebo-controlled pilot study was to investigate the safety, feasibility and acceptability of a novel electroencephalography-based neurofeedback (EEG-NF) training protocol, targeting effective connectivity from the pgACC to S1 in the alpha band and exploring its trend of effect on pain and function.
Participants with fibromyalgia (N=24; 11 active, 13 placebo) received 12 sessions of either EEG-NF targeting effective connectivity from pgACC to S1, or placebo NF. Feasibility measures were recorded throughout. Outcome measures of pain (Brief Pain Inventory) and function (Revised Fibromyalgia Impact Questionnaire) were collected at baseline, immediately (~two days), ten days and one-month post-intervention. Descriptive statistics demonstrate that effective connectivity NF training is feasible (recruitment rate of 6 participants per month, mean adherence rate of 80.5% and dropout rate 25%) safe (no adverse events reported) and highly acceptable (average score 8.3/10). Active treatment and placebo groups were comparable in their marked decrease in pain and functional impact. We hypothesize a range of reasons for this, including a potential correlation to fatigue at baseline and variability in individual cortical connectivity at baseline. EEG NF training effective connectivity is a safe, feasible and acceptable treatment approach for fibromyalgia. Future studies could validate the methodology used in this study and improve the protocol design to be used in a fully powered clinical trial.