An Evaluation of Transcutaneous Electrical Nerve Stimulation (TENS) for the Treatment of Pain Related to a Spinal Cord Injury

Pain is a major problem in the spinal cord injury (SCI) population. Patients with a SCI often suffer from either centrally-mediated pain (neurogenic pain) or peripherally-mediated pain (musculoskeletal pain). The physical therapy technique known as TENS is often used to treat SCI related pain problems. However, the efficacy of TENS in SCI has yet to be tested. Moreover, previous research suggests that response to TENS may in part determined by subject expectation of a potent medical treatment (Deyo et al., 1990; Langley et al., 1984). The present investigation evaluated: (1) the efficacy of TENS in the SCI population, (2) whether or not patient treatment expectancy influences outcome, and (3) whether the aforementioned factors differentially influence centrally and peripherally mediated pain. Findings suggest that treatment expectation concomitant to TENS treatment may be important in potentiating reductions in distress associated with pain across different types of pain. Additionally, positive treatment expectation may be effective on directly reducing peripherally-mediated pain, but not centrally-mediated pain. The findings are discussed in relation to current biological and psychological theories of pain modulation.