The goal of this pilot clinical trial is to find out how well low dose naltrexone works for people with pain due to spinal cord injury. The main questions it aims to answer are: will low dose naltrexone reduce pain, and increase the quality of life for people with central neuropathic pain due to spinal cord injury. Hypothesis 1: LDN will decrease the severity of CNP in adult patients with SCI as measured by the Neuropathic Pain Scale (NPS) Hypothesis 2: LDN will improve quality of life of patients with SCI as measured by various validated clinical tools There is no comparison group. This study is being completed to give investigators more information for how to best run a larger clinical trial. Participants will be asked to take an oral dose of 4.5mg of naltrexone, daily, for 12 weeks.