PEMF fails to enhance nerve regeneration after sciatic nerve crush lesion

Abstract

The use of electromagnetic fields has been reported to enhance peripheral nerve regeneration. This study aimed to identify the effects of a prolonged protocol of low-frequency pulsed electromagnetic field (PEMF) on peripheral nerve regeneration. Thirty-four male Swiss mice (Mus musculus) were divided into PEMF (n = 17) and control (n = 17) groups. All animals underwent a unilateral sciatic-crush lesion, and the PEMF group was exposed to a 72-Hz, 2-G electromagnetic field for 30 min, five days a week, for three weeks. Functional analysis was carried out weekly. After three weeks, the animals were euthanized, and histological, morphometric, oxidative stress, and TGF-β1 analyses were performed. Functional analysis showed no differences between the groups. Histological appearance was similar between PEMF and control nerves. Morphometric assessment showed that the PEMF nerves trended toward decreased regeneration. The levels of free radicals were more pronounced in PEMF nerves, but were not associated with an increase in the content of the TGF-β1/Smad signaling pathway. Prolonged PEMF regimen leads to delayed histological peripheral nerve regeneration and increased oxidative stress but no loss of function recovery.