The study will be recruiting people who have had a limb amputation (traumatic or atraumatic) and are experiencing chronic phantom limb pain (PLP). Participants will be asked to be seated during the study session. Non-painful peripheral stimulation will be applied to elicit a brain response. Electrodes will be placed on the scalp to record these electrical brain responses during the study session. Visual feedback based on the response will be provided in pseudo realtime. The study will involve three 1-hour sessions per week for 8-9 weeks, followed by 2 follow-up sessions at 3 and 6 months after the last session. Assessments of pain intensity and quality, and neurophysiological sensorimotor response, will be performed before the first session, after the last session, and at follow-up sessions. Additional electroencephalography (EEG) based assessments will also be performed as exploratory measures, to assess inter- and intra- hemispheric functional connectivity and sensorimotor responses associated with amputation and operant conditioning training.
The study will investigate the application of a non-pharmacological operant conditioning approach to reduce phantom limb pain (PLP). PLP afflicts 60-90% people who have lost a limb. It can last for years and lead to drug dependence, job loss, and poor quality of life. Current non-pharmacological interventions are encouraging but limited, and their efficacy remains unclear. Limb amputation is known to lead to abnormal sensorimotor reorganization in the brain. Multiple studies have shown that PLP severity is correlated with the extent of this reorganization. The current study will train participants via realtime feedback of brain responses to promote more normal sensorimotor response, with the goal to reduce phantom limb pain.