RESUMEN
OBJECTIVE: To explore and determine the reorganizational changes in the cortical neural circuits associated with pruritis, this study was undertaken to compare the electroencephalography (EEG) changes in burn patients having primary symptoms of chronic itching (pruritis) and their paired healthy subjects. METHODS: Eight subjects were recruited for this exploratory pilot study: 4 patients with pruritus after burn injury matched by gender and age with 4 healthy subjects. EEG recordings were analyzed for absolute alpha, low beta, high beta, and theta power for both groups. RESULTS: The mean age of the burn patients was 41.75 years; while the mean age for the matched healthy subjects was 41.5 years. All subjects were male. A decreased alpha activity was observed in the occipital channels (0.82 vs. 1.4; p=0.01) and a decreased low beta activity in the frontal area (0.22 vs. 0.4; p=0.049) in eyes closed conditions. An overall decreased theta trend was observed in both the eyes open and eyes closed conditions in burn patients, compared to healthy individuals. CONCLUSION: This preliminary study presents initial evidence that chronic pruritus in burn subjects may be associated with brain reorganizational changes at the cortical level characterized by an EEG pattern.
RESUMEN
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.
