A colocação dos eletrodos interfere na antihiperalgesia promovida pela tens?

• Autor(a) principal: Poderoso Neto, Maurício Lima
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: https://ri.ufs.br/handle/riufs/3917
• topic: Estimulação elétrica transcutânea do nervo; Dor; Eletrodos; Eletroterapia; Fisioterapia; Transcutaneous electrical nerve stimulation; Pain; Electrodes; CNPQ::CIENCIAS DA SAUDE::MEDICINA

Among the non-pharmacologic therapy resources for inflammatory pain treatment, transcutaneous electric nerve stimulation (TENS) has been gaining attention in the literature. However, the clinical literature on TENS is sometimes difficult to be interpreted due to limitations in clinical trials and little methodological rigor. Another controversial issue is the lack of standardization in the parameters of the current as well as the ways of application of the electrodes, both needing to be better elucidated. Methods: Carrageenan and kaolin were used to (3%) to mimetize knee ostheoarthritis in rats. Twenty-five male Wistar rats were divided according to electrodes location in 5 groups (n=5, in each group): ipsilateral dermatome, contralateral dermatome, paravertebral, acupoints (Bp6 and E36) and control group. The frequency and the duration of the application were the same in all groups. In all groups, thermal and secondary mechanical hyperalgesia, as well as motor performance and joint edema were measured before and after TENS was applied by stimulating rats with 4 Hz,100 μs of pulse duration, at a sensory intensity during 20 minutes. Mechanical withdrawal threshold was tested for the differences between the treatment groups by using Kruskal Wallis followed by Tukey test, Wilcoxon Matched Pairs test for differences into the group and Friedman followed by Turkey test for repeated measures. P values less than 0.05 were considered significant. Results: Following TENS application with electrodes placed on ipsilateral or contralateral dermatome, paraspinal muscles or acupoints, there was a significant reduction in both mechanical and thermal hyperalgesia. Moreover, an increase in time for performing rota rod test when compared to control group and prior TENS was observed in all groups treated with active TENS. However, there was no difference for the edema between groups. The intensity was significantly lower in the contralateral dermatome in comparison to other electrode placements. Results for paw withdrawal latency and threshold and intensity suggest there is a tendency for developing tolerance to TENS after the fifth day of stimulation. Conclusion: It seems that TENS-induced antihyperalgesia does not depend on the electrode placement, indicating TENS acts through the central nervous system.