Transcutaneous Electrical Nerve Stimulation for the Management of Neuropathic Pain: The Effects of Frequency and Electrode Position on Prevention of Allodynia in a Rat Model of Complex Regional Pain Syndrome Type II

• Published in: Physical therapy Vol. 86; no. 5; pp. 698 - 709
• Main Authors: Somers, David L, Clemente, F Richard
• Format: Journal Article
• Language: English
• Published: United States American Physical Therapy Association 01.05.2006; Oxford University Press
• Subjects: Acupuncture Points; Animals; Care and treatment; Causalgia - prevention & control; Comparative studies; Complications and side effects; Data Interpretation, Statistical; Disease Models, Animal; Effects; Electroacupuncture; Electrodes; Injuries; Male; Methods; Models, Theoretical; Muscular system; Neurons; Pain; Pain Measurement; Peripheral nerve diseases; Peripheral nervous system diseases; Physical therapy; Physiological aspects; Prevention; Rats; Rats, Sprague-Dawley; Risk factors; Sciatic Nerve - injuries; Spinal cord; Time Factors; Transcutaneous Electric Nerve Stimulation - methods; Transcutaneous electrical nerve stimulation; United States
• ISSN: 0031-9023; 1538-6724
• DOI: 10.1093/ptj/86.5.698

Background and Purpose. Complex regional pain syndrome type II (CPSII) is a painful condition that develops following a nerve injury. Although transcutaneous electrical nerve stimulation (TENS) relieves the pain of CPSII, the stimulation parameters that would best prevent the development of the condition are not known. The purpose of this study was to compare the ability of several different stimulation strategies to reduce the development of allodynia. Subjects. Sprague-Dawley rats were used in the study. Methods. A chronic constriction injury (CCI) to the right sciatic nerve was used to induce allodynia. Two groups of CCI rats received high-frequency TENS to the lumbar paravertebral region with electrodes positioned on the skin overlying either the right or left paraspinal musculature. Two additional groups of CCI rats received low-frequency TENS to acupuncture points in the right or left hind limbs. A fifth group of CCI rats received no TENS intervention. Thermal and mechanical pain thresholds were assessed in the right hind paw before and 12 days after the CCI surgery. The TENS was delivered 1 hour per day beginning on the day of surgery. Results. Daily high-frequency TENS reduced the development of mechanical allodynia in CCI rats, and low-frequency TENS reduced the development of thermal allodynia, but only when TENS was delivered on the left side. Discussion and Conclusion. The results indicate that TENS delivered contralateral to a nerve injury best reduces allodynia development. Comprehensive reduction of allodynia development would require a combination of high- and low-frequency TENS intervention.