The effects of transcranial direct current stimulation on neuropathic pain following spinal cord injury: Practical research results from Vietnam

Subjects: This study aimed to assess the efficacy of transcranial direct current stimulation (tDCS) targeting the primary motor cortex (M1) in treating neuropathic pain (NP) following spinal cord injury (SCI). Material and methods: Twenty patients with NP after SCI were enrolled. Before treatment, single-pulse transcranial magnetic stimulation (TMS) was utilized to locate the M1 regions. Subsequently, patients underwent tDCS stimulation with the anode over M1 region and the cathode over the contralateral orbitofrontal (COF) region. Treatment involved a 2 mA anode current for 20 min daily, five days per week, for four consecutive weeks. Douleur Neuropathique en 4 Questions (DN4) and Numerical Rating Scale (NRS) (0–10) were assessed before treatment, immediately after treatment and during the 1 and 3-month follow-up periods. Results: Significant improvements were seen right after treatment, with the DN4 score dropping from 5.4 (± 2.8) to 3.6 (± 2.3) and NRS from 5.8 (± 1.8) to 3.8 (± 1.9). This effect was sustained for one month after treatment cessation. Common side effects included drowsiness and a transient stinging sensation in the scalp, which were self-resolving. Conclusion: tDCS stimulation in the M1 region can effectively alleviate NP symptoms after SCI in the short term, with no severe side effects. Further research with larger sample sizes is warranted to determine optimal regimens for enhancing pain relief effectiveness and extending the duration of pain relief for patients.