Microelectric Treatment by Transcutaneous Electrical Nerve Stimulation in a Rat Model of Acute Spinal Cord Injury

ABSTRACT

STUDY DESIGN: Animal study. OBJECTIVES: To investigate the effects of microelectric treatment by transcutaneous electrical nerve stimulation (TENS) on functional recovery and histological changes in a rat model of spinal cord injury (SCI). SUMMARY OF LITERATURE REVIEW The effects of TENS on spasticity and its underlying mechanisms remain unclear. MATERIALS AND METHODS: SCI was induced by a 1.5-mm impactor with 200,000–260,000 dyne after laminectomy. Rats were divided into the following groups group I (normal control), group II (microelectric treatment of 0 A), group III (microelectric treatment of 100 µA for 1 hr/day), group IV (microelectric treatment of 400 µA for 1 hr/day), and group V (microelectric treatment of 400 µA for 24 hr/day). After inducing SCI, rats were assessed by a sensory test with von Frey filaments and the locomotor recovery test (BBB rating scale) at 1, 4, 7, 14, 21, and 28 days. To evaluate spinal cord damage, histopathological studies were performed with hematoxylin and eosin. Brain-derived neurotrophic factor (BDNF) and TrkB immunohistochemistry studies were performed at 28 days. RESULTS: In groups IV and V, the BBB score had significantly improved on days 21 and 28 after SCI, and the TENS-treated groups showed significant neuronal recovery. After SCI, groups IV and V showed a significant recovery of locomotor function and the motor sensory response of the withdrawal threshold to 3.5 g. In addition, necrotic tissue and cystic spaces in the spinal cord were significantly reduced and BDNF/TrkB-positive cells were highly expressed in groups III, IV, and V. CONCLUSIONS: Microelectric treatment can play a role in facilitating the recovery of locomotion following SCI.