Reliability of sympathetic skin response in individuals with spinal cord injury: a supraorbital nerve stimulation approach

Objectives: To assess the test-retest reliability of sympathetic skin response (SSR) using supraorbital nerve stimulation method in individuals with spinal cord injury (SCI). Study design: Psychometric property testing. Setting: A rehabilitation facility in Chiang Mai, Thailand. Methods: SSR was done on two executive days in individuals with SCI, stimulating at supraorbital nerve and recording at the palmar and plantar surface of both hands and feet. Results were reported as hand- and foot-SSR scores. Test-retest reliability was analyzed using intraclass correlation coefficients (ICC). Results: Forty individuals with SCI were recruited. ICC of hand and foot SSR scores were 0.963 (95%CI: 0.888–0.967) and 0.833 (95%CI: 0.707–0.908), indicating excellent and good test-retest reliability, respectively. Subgroup analyses showed a problematic decrease in test-retest reliability to a moderate level of the foot SSR score in the elderly subgroup (age ≥ 60). Conclusion: SSR induced by the supraorbital nerve stimulation showed excellent test-retest reliability for hand SSR and good reliability for foot SSR in the overall SCI population. SSR, induced by supraorbital nerve stimulation method and reported by SSR score, should be a reliable tool for evaluating autonomic functions in individuals with SCI.