An Open Label Feasibility Study on Impact of rTMS Versus Drug Therapy on Phantom Limb Pain in Lower Limb Amputation Patients: A Randomized Controlled Trial

Abstract

Background: Phantom limb phenomena, a sensation in a lost body part, have been a medical and folklore issue since 1797. In amputees, phantom limb pain (PLP) is common, with incidence ranging from 42.2 to 78.8%. Multidisciplinary treatment required for management of PLP. Objective: The purpose of the current study is to compare the efficacy of repetitive transcranial magnetic stimulation (rTMS) comparted to drug therapy in the management of phantom limb pain (PLP), as well as to assess rTMS effectiveness at the fourthand eighth-weeks following amputation. Methods: A prospective randomized controlled trial with ethical approval and trial registry is planned with a pilot sample size of 50 patients. The study includes patients aged 18-65, all genders, undergoing traumatic lower limb amputation, reporting phantom limb pain, without ICU stay exceeding 48 hours. Patients in rTMS group will undergo 10 continuous sessions, lasting 15 minutes each. 30 trains of magnetic pulses, each lasting 20 seconds, will be applied at 1Hz over left motor cortex, at 80% of the resting motor threshold, with a 10-second inter-train interval. Patients in drug therapy group will receive monitored drug dispensing, including a combination of medications as per the Institute's protocol. Patients will be assessed for psychological scales and serotonin 5 HT at fourth- and eighth-week post amputation. Results: It is expected that rTMS therapy which is non-invasive will reduce the usage of drug therapy in management of phantom limb pain. Conclusion: The study will investigate the safety and feasibility of using rTMS in traumatic lower limb amputation patients for managing phantom limb pain, comparing it with drug therapy.