Effects of visual illusion and transcutaneous electrical nerve stimulation on neuropathic pain in patients with spinal cord injury: A randomised controlled cross-over trial.

Abstract

Chronic pain is a common consequence of spinal cord injury (SCI). No therapeutic drugs or drug groups are proven to be superior for neuropathic pain and treatments only aim to convert pain from dull to tolerable levels and not to remove it. This study was planned to compare the effect of visual illusion (VI) and transcutaneous electrical nerve stimulation (TENS) on pain intensity, pain quality and functional capacity in SCI patients with neuropathic pain. Twenty-four patients were included and randomly categorized into two groups. In the first group (n= 12), visual illusion was applied for first two weeks, 1 week wash out period and then TENS was applied for 2 weeks. In second group (n= 12), TENS was applied firstly, 1 week wash out and then %visual illusion VI were applied. Pain severity, pain quality, and functional capacity were assessed with the visual analog scale (VAS), the neuropathic pain scale (NPS), and the brief pain inventory (BPI), respectively. A pre-post-treatment and cross over design was used. Wilcoxon signed-rank tests were used for within group analyses. Mann-Whitney U tests were used for analyses that compared different groups. It was observed that pain intensity decrease immediately after both applications (VI: p= 0.07, TENS: p= 0.08). After TENS application for 2 weeks, it was observed that significant decrease in most (p= 0.04) and less (p= 0.02) pain intensity; while there was no significant decrease in pain intensity after 2 weeks for VI (p> 0.05). When findings of NPS were analyzed, hot (p= 0.047), sharp (p= 0.02), unpleasant (p= 0.03) and deep items (p= 0.047) decreased after VI application. When the results of BPI were detected, they were observed that the negative effect of pain on moving ability (p= 0.04) after visual illusion application and the negative effect of pain on mood (p= 0.03), relationships with others (p= 0.04) and sleep (p= 0.04) after TENS application decreased significantly. TENS and VI therapies can be successfully used in clinical practice as an alternative treatment or as a supportive method separetely or together.