Neurofeedback for chronic low back pain.

INTERVENTION: Electroencephalography based infraslow frequency (o.o1‐0.1 Hz) neurofeedback (ISF‐NF) will be administered three times a week (30 minutes/ session) for a total of 4 weeks, by an experienced researcher. During each session, participants will be asked to close their eyes and sit relaxed on a chair with back supported. No form of stimulus will be given. The Comby EEG lead cap with sensors will be placed on the individual’s scalp. The targeted brain regions will include the pregenual anterior cingulate cortex (pgACC), dorsal anterior cingulate cortex (dACC), and primary somatosensory cortex (SSC). For the active ISF‐NF treatment groups, the Brainmaster Inc. system delivers a sound feedback (reward) each time the participant’s real‐time brain activity at the targeted regions meets the desired infraslow threshold (0.0–0.1 Hz). The infraslow activity will be down‐trained at the pgACC (Group 1), up‐trained at the dACC+SSC (Group 2), and simultaneously up‐trained at pgACC and down‐trained at dACC+SSC (Group 3). For all the active ISF‐NF treatment groups, the reward threshold will be adjusted in real‐time between 60‐80%, i.e., for 60‐80% of the time, a sound feedback (reward) will be delivered by the system when the participant's real‐time brain activity at the targeted regions meets the desired infraslow magnitude (threshold). For placebo ISF‐NF treatment group, a pre‐recorded sound feedback will be played to create an identical auditory feedback to the active treatment groups. CONDITION: Chronic low back pain; ; Chronic low back pain Musculoskeletal ‐ Other muscular and skeletal disorders PRIMARY OUTCOME: Brief Pain Inventory [Baseline, immediately post‐intervention, and at follow‐up of 1 week and 1 month post‐intervention] Feasibility and safety measures; ; • Recruitment rate, i.e., number of participants recruited per month, until the proposed sample size is reached. The recruitment rate will be recorded by PI on a weekly basis, since the release of the advertisements, and the number of advertisements will also be recorded.; • Proportion of participants recruited from the total number screened (with reasons for exclusion), expressed as a percentage.; • Adherence to intervention measured as number of treatment sessions attended by each participant, and expressed as a percentage of the total number of sessions. Adherence rates will be calculated once the treatment phase is completed.; • Drop‐out rates, measured as the number of participants who dropped‐out in each group, and expressed as a percentage of the total number of participants enrolled in the study. Drop‐outs rates will be calculated once the follow‐up phase is completed.; • Participant satisfaction levels regarding treatment and the acceptability of the ISF‐NF will also be recorded on an 11‐point numeric rating scale (0‐Not at all satisfied/acceptable to 10‐Very satisfied/acceptable). ; ; Any adverse effects (e.g., headache, pain flare‐ups) that likely have a causal relationship with the intervention will be recorded by the treating researcher.[Throughout the intervention period and at follow up of 1 week and 1 month post‐intervention] Roland–Morris Disability Questionnaire[Baseline, immediately post‐intervention, and at follow‐up of 1 week and 1 month post‐intervention] SECONDARY OUTCOME: Condition pain modulation (CPM): ; Conditioning stimulus will consist of a cold pressor task, where the participants will be asked to immerse their hand (until mid‐forearm), in a thermos containing circulating cold water ( 5 degree C) for a maximum period of 2 minutes. ; [Baseline, immediately post‐intervention, and at follow‐up of 1 week and 1 month post‐intervention] Experimental pain measures: Mechanical temporal summation (MTS) INCLUSION CRITERIA: Participants with a diagnosis of CLBP will be eligible to participate. To be included in the study, participants must meet all of the following INCLUSION CRITERIA: ; Test stimulus: A computerised, handheld digital algometer (AlgoMed; Medoc, Ramat Yishai, Israel) will be used to measure suprathreshold pressure pain threshold (pain40) at the most painful low back region (nominated by the participant). Two PPT (pain40) trials will be recorded before the conditioning stimulus and will be averaged (pre average score) to obtain a baseline score for each participant. Three PPT (pain40) trials will be recorded in the same region at 30, 60, and 90 seconds immediately after the conditioning stimulus. A percent change score will be calculated for each time point ; MTS will be assessed using a nylon monofilament (Semmes monofilament 6.65, 300 g). Brief ten repetitive contacts will be delivered at a rate of 1 Hz, externally cued by auditory stimuli. The participants will be asked to rate the level of pain experienced on the 11 point numeric pain rating scale (NPRS, 0=No pain to 100=Extreme pain) immediately after the first contact, and also to rate their greatest pain intensity after the 10th contact. Three trials will be conducted for each of the three regions (i.e., symptomatic low back region, non‐symptomatic low back region, and the distant non‐dominant wrist). [Baseline, immediately post‐intervention, and at follow‐up of 1 week and 1 month post‐intervention] Pressure pain threshold (PPT): A computerised, handheld digital algometer (AlgoMed; Medoc, Ramat Yishai, Israel) will be used to measure three trials of PPT over the the three regions (i.e., symptomatic low back region, non‐symptomatic low back region, and the distant non‐dominant wrist). The 1‐cm2 algometer probe will be pressed over the marked test site perpendicularly to the skin at a rate of 30 kPa/s. The participants will be instructed to press the algometer trigger button in the patient control unit when the pressure sensation changes to first pain. Once the patient‐controlled unit is activated, the trial is automatically terminated, and the amount of pressure (kPa) will be recorded. [Baseline, immediately post‐intervention, and at follow‐up of 1 week and 1 month post‐intervention] • Capable of understanding and signing an informed consent form • Age between 35 to 75 years on the day of the consent • Pain in the lower back area (region between the 12th rib and the gluteal fold) that occurs every day for more than or equal to 3 months • A score of more than 4 on the 11‐point numeric pain rating scale (NPRS, 0 is No pain to 10 is Worst pain) in the past 4 weeks • A disability score of more than or equal to 5 on Roland–Morris Disability Questionnaire