A feasibility study assessing cortical plasticity in chronic neuropathic pain following burn injury

The aim of this article is to evaluate the neuroplastic changes associated with chronic neuropathic pain following burn injury and modulation feasibility using transcranial direct current stimulation (tDCS). This is a crossover, double-blinded case series involving three patients with chronic neuropathic pain following burn injury. Participants were randomly assigned to undergo single sessions of both sham and active anodal tDCS over the primary motor cortex, contralateral to the most painful site. Excitability of the motor cortex was assessed before and after each stimulation session with the use of transcranial magnetic stimulation. An overall decrease in cortical excitability was seen after active tDCS only, as characterized by a decrease in intracortical facilitation and amplitude of motor evoked potentials and an increase in intracortical inhibition. Clinical outcomes did not change after a single session of tDCS. Results are consistent with previous studies showing that patients with chronic neuropathic pain have defective intracortical inhibition. This case series shows early evidence that chronic pain following burn injury may share similar central neural mechanisms, which could be modulated using tDCS.