Efficacy of Physical Exercise on Cortical Activity Modulation in Mild Cognitive Impairment: A Systematic Review

Objective: To investigate the effects of physical exercise on cortical activity measured via electroencephalogram (EEG) in individuals with mild cognitive impairment (MCI). Data Sources: PubMed, Web of Science, PsycINFO, and SciELO databases were searched using: "physical exercise," "physical activity," "physical therapy," "exercise," "training," "electroencephalogram," "electroencephalography," "EEG," "mild cognitive impairment," "cognitive dysfunction," and "MCI." The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement was followed and the Physiotherapy Evidence Database scale was used to assess the risk of bias of each study. Study Selection: Original articles, sample including individuals with MCI, physical exercise intervention, use of EEG to measure cortical activity. Data Extraction: Sample characteristics, physical exercise protocol characteristics, results related to effects of physical exercise on parameters derived from EEG signals, strengths, limitations, and conclusions of the studies were selected by 2 investigators. Data Synthesis: A total of 365 articles were identified in electronic databases. After the selection stage, 7 studies were included. Although there was a large spectrum of type of exercise (aerobic, resistance, multimodal, exergames, combined exercise with cognitive training), all exercise protocols altered cortical activity in patients with MCI. An exercise session (acute response) causes power reduction of delta band and increases complexity and P300 amplitude in resting-state EEG. After an intervention with an exercise program (chronic response), there was a reduction in the power of delta and theta bands and an increase in beta and alpha bands, as well an increase in complexity in resting-state EEG. Conclusions: Physical exercise seems to play a role in cortical activity in patients with MCI, suggesting neural plasticity in such individuals. Archives of Physical Medicine and Rehabilitation 2021;102:2393-401 (c) 2021 The American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.