Transcranial direct current stimulation (tDCS) and trigeminal pain: A preclinical study.

Abstract

Our objective was to evaluate the Transcranial direct current stimulation (tDCS) effect on facial allodynia induced by chronic constriction of the infraorbital nerve (CCI-ION) and on the brainstem levels of TNF-α, NGF, IL-10, and serum LDH in rats. Rats were exposed to the CCI-ION model. Facial allodynia was assessed by von Frey filaments test at baseline, 3, 7, 10, and 14days postsurgery and 24hr and 7days after the bimodal tDCS sessions for 20min/day/8days. Chronic constriction of the infraorbital nerve induced a significant decrease in the mechanical threshold 14days after surgery. This effect was reversed by tDCS treatment, with the mechanical threshold returning to basal levels at 24hr after the end of the treatment and it persisted for 7days after the end of the treatment. tDCS also decreased LDH serum levels compared to those in the control group. There was an interaction between pain and treatment with respect to brainstem levels of NGF, TNF-α, and IL-10. Chronic constriction of the infraorbital nerve model was effective in establishing trigeminal neuropathic pain on 14days after surgery, and tDCS reduced allodynia and LDH serum levels and promoted alterations in NGF, TNF-α, and IL-10 brainstem levels. Thus, we suggest that tDCS may be a potential therapy in the trigeminal pain treatment.