Electromagnetic field stimulation for long-term mobility assessment after sciatic nerve injury.

Introduction: Gauss (G) or miliTesla (mT) units measure electromagnetic field (EMF) stimulation. Tarlov Scale (TS) assesses motor impairment, Finger Abduction Scale (FAS) measures finger separation. The objective is to evaluate mobility using EMF in a Sciatic Nerve Injury (SNI) model.

Materials & methods: SNI caused paresis in the right hind limb to observe motor changes in male Sprague-Dawley rats (372-529 g) (N = 30). Three groups of (n = 10) rats were created. Control Group (CG) was just injured. The experimental groups were EMF-treated two hours a day for four weeks (2/24, 5/7, 4/4), applying Gauss intensities: Low-Intensity (LIMF) 60-100 (6-10 mT) & High-Intensity (HIMF) 140-200 (14-20 mT). The mobility was measured each week with TS & FAS. Sciatic nerve & skeletal muscle histological slides were made with traditional staining technique to evaluate cellular inflammation. We used two-tailed repeated ANOVA measures & Bonferroni post hoc tests, with a significance p < 0.05 (α = 0.05) and β = 80%.

Results: EMFs effectively treat SNI in rats, improving the mobility of the right hind limb in experimental groups. In the last week, TS scores were CG 3.5 (±1.35) p = 0.006, LIMF 4 (±0) p = 0.0001 & HIMF 4.3 (±0.82) p = 0.02. FAS scores were CG 0.2 (±0.42) p = 0.000001, LIMF 1.5 (±0.70) p = 0.05 & HIMF 1.8 (±0.42) p = 0.1. In histological findings, CG had inflammation in nerve & muscle, LIMF & HIMF diminished cellular activity.

Discussion: TS & FAS helped to improve mobility in experimental groups using EMFs after SNI. The nerve repairing mechanism should be studied in future models.