Role of Stem Cells on Neuropathic Pain Recovery in Patients with Spinal Cord Injury: A Systematic Review

Stem cell transplantation has shown promise in providing pain relief for patients with chronic SCI by releasing transforming growth factor β (TGF-β). This systematic review aims to evaluate stem cell's effectiveness in recovering neuropathic pain in patients with spinal cord injury. The study followed the PRISMA guidelines and included patients with chronic spinal cord injury who received stem cells compared with a control group. The recovery in neuropathic pain was analyzed. The response of stem cell transplantation on neuropathic pain intensity was analyzed across different studies, and the relevant data is presented in the present systematic review. The search results identified 478 records, and 15 articles were included in the systematic review. 9/15 studies reported an increase in neuropathic pain after stem cell transplantation; out of the nine studies, six had a control group. In the included studies with a control group, the rate of development of neuropathic pain was more solely in the treatment arm in 3/6 studies. Two authors reported the presence of neuropathic pain in the control group. The level of evidence in included studies is weak, the reasons may be only phase 1 clinical trial, inclusion of different severity of SCI, use of various stem cell types, varied dosages, timings, lack of control group, use of varying assessment scores, subjective assessment of pain, and lack of direct evidence which can be link cause to the effect.