Effect of DLPFC Targeted rTMS on Phantom Limb Pain and Associated Psychological Comorbidities: A Pilot Randomized Controlled Trial.

BACKGROUND & AIM: Maladaptive cortical plasticity is central to the pathophysiology of phantom limb pain (PLP), a condition often accompanied by sleep disturbances, anxiety, and depression states affecting quality of life. Repetitive transcranial magnetic stimulation (rTMS) has potential for relieving chronic neuropathic pain. Dorsolateral prefrontal cortex (DLPFC) is a critical component of neural circuitry subserving pain processing and associated affective aspects of pain. rTMS induced neuromodulation of DLPFC could be a potential therapeutic strategy in PLP management. Present study explored the role of rTMS of DLPFC on pain, anxiety, depression, and quality of life in PLP patients. METHODS: Twenty-seven traumatic amputees with PLP were randomized into real or sham rTMS group. Real rTMS therapy included 10 sessions over 2 weeks, with 1Hz stimulation at 90% resting motor threshold applied to DLPFC contralateral to amputation site. For sham rTMS therapy, same protocol was used, except coil was placed perpendicular to the scalp, preventing actual stimulation. The primary outcome was pain intensity assessed using Visual Analogue Scale. Secondary outcomes included pain assessment using Short-Form McGill Pain Questionnaire, anxiety using Hamilton Anxiety Rating Scale, depression using Hamilton Depression Rating Scale, and quality of life using WHO quality of life-BREF questionnaire. Assessments were performed at baseline, after 10th session, and during follow-up on days 15, 30, and 60 post-therapy. RESULTS AND CONCLUSION: rTMS on DLPFC was associated with improvement in PLP, anxiety, depression, and quality of life. The findings suggest the potential of DLPFC-rTMS as an adjunctive modality in the management of PLP.