Quantitative Electroencephalography and Surface Electromyography Correlations upon Predictable and Unpredictable Perturbation in Older Adults

BACKGROUND: Quantitative Electroencephalography (qEEG) is a non-invasive method used to quantify electrical activity over the cortex. QEEG provides an accurate temporal resolution of the brain activity, making it a useful tool for assessing cortical function during challenging tasks. OBJECTIVE: This study aimed to investigate postural adjustments in older adults in response to an external perturbation. MATERIAL AND METHODS: In this observational study, nineteen healthy older adults were involved. A 32-channel qEEG was employed to track alterations in beta power on the electrodes over the two sensory-motor areas. Integrated electromyographic activity (IntEMG) of the leg muscles was evaluated in response to perturbations under predictable and unpredictable conditions. RESULTS: The results indicated higher beta power during late-phase in the Cz electrode in both conditions. IntEMG was significantly greater in the tibialis anterior muscle during both conditions in the CPA epoch. In predictable condition, a positive correlation was found between the beta power over C(4) (r = 0.560, p = 0.013) and C(3) (r = 0.458, p = 0.048) electrodes and tibialis anterior muscle amplitude, and between beta power in C(4) and gastrocnemius amplitude (r = 0.525, p = 0.021). In unpredictable condition, there was a positive correlation between beta power over the C(4) and the tibialis anterior amplitude (r = 0.580, p = 0.009) and also it over the C(3) and the tibialis anterior amplitude (r = 0.452, p = 0.049). CONCLUSION: Our findings demonstrate that sensorimotor processing occurs in the brain during response to perturbation. Furthermore, cortical activity appeared to be greatest during the recruitment of the muscles upon late-phase in older adults.