Electroencephalographic analysis in patients with intercostal brachialgia after surgical treatment of breast cancer undergoing transcutaneous electrical stimulation (TENS)

Abstract

Introduction: Cancer is a world problem of public health. Pain is one of the most frequent symptoms. It’s known that the state of pain can be attenuated with specific procedures of oncological services. The oncological pain control is a subject which has aroused interest among researchers, especially in physical therapy. Among the tools for the decrease of pain, the transcutaneous electrical nervous stimulation (TENS) has been highlighted. Even though it has been used largely, there is not a consensus e about its application, mainly in patients that underwent through mastectomies with complaints of painful or possible modifications in the somatosensory cerebral cortex of those patients. Objective: This perspective the goal of this study was to verify possible strong electrocortical alterations after the use of TENS in people with Intercostobrachial Neuralgia due to post-mastectomy through the quantitative electroencephalography (QEEG). Methods: Eight people were analyzed divided in group A (TENS acupuncture) and group B (TENS burst). These people were undergone through evaluation in QEEG in which the electrodes of interest were P3-PZ-P4 and concomitantly the analysis of pain was done by the visual analogue scale (VAS). The data was undergone through the test of Kolmogorov-Smimov for the analysis of normality and to the ANOVA for the comparison among the conditions (5, 10, 15 and 20 minutes), groups (TENS acupuncture and burst) and electrodes P3-PZ-P4 with level of significance of 95%. Results: The results showed a main effect in the condition and location, occurring a decreasing of the relative power of slow alpha (8-10Hz) and fast (10-12Hz) in all of the electrodes of interest. This indicates an enlargement of the activities on the somatosensory areas in relation to the state of rest (pain), after the application of TENS in both groups. Thus, TENS caused electrocortical alterations in the somatosensory areas that corroborate the obtained results with the diminishment of the pain. Conclusion: It was concluded that TENS promotes important cortical alterations in the absolute power of alpha band. New studies must be proposed especially with beta bands, gamma and also with other EEG investigation methods to elucidate the real mechanism of cortical activity reduction with the application of TENS.