Doctor of Philosophy
Petrella, Robert J.
Cognitive decline is increasing with the aging population and, at present, there is no effective pharmacologic treatment available. Exercise interventions may impart protection against cognitive decline. A novel exercise approach is multiple-modality exercise (MME; aerobic, resistance, and balance exercise) with mind-motor training. Mind-motor training is a promising intervention in the study of cognitive function. Combining MME with mind-motor training may improve or maintain cognition and provide prevention of dementia early in the course of cognitive decline. Individuals with subjective cognitive complaints (SCC) comprise an at-risk group early in the spectrum of cognitive decline that could be targeted for prevention. The objectives of this thesis were to report on the current state of evidence regarding the effects of MME in cognition and neuroimaging outcomes in older adults without dementia, and determine whether MME with mind-motor training benefit cognition, mobility, and neuroimaging outcomes in older adults with SCC. A scoping review of MME studies in older adults without dementia was conducted, as well as a 24-week randomized controlled trial (RCT) with a 28-week no-contact follow-up in community-dwelling older adults with SCC. Main findings were as follows: the scoping review concluded that although MME may improve cognition and neuroimaging outcomes compared to controls, confounding factors may account for these effects given that MME does not seem to evoke similar effects when compared to other interventions. Results from an RCT revealed that 24 weeks of MME with mind-motor training showed trends for greater improvements in global cognitive functioning and memory. These trends were confirmed after a 28-week no-contact follow-up. For mobility outcomes, MME alone was effective in improving gait performance under usual and dual-task conditions, while MME and mind-motor training did not seem to impart benefits to mobility. An exploratory study of memory and neuroimaging data revealed that MME and mind-motor training yielded greater benefits than MME alone in visuospatial memory, with changes in functional connectivity in brain areas of motor function and in brain regions relevant to Alzheimer’s disease risk. In conclusion, MME with mind-motor training is a promising strategy to improve cognition with potential to invoke neuroplasticity associated with improved memory, and reduce dementia risk.
Summary for Lay Audience
Older adults with memory complaints may be an ideal group to be targeted for dementia prevention programs, including multiple-modality exercise (MME) interventions (e.g., combining aerobic, resistance, and balance exercises). Mind-motor training is a promising intervention that could also reduce dementia risk. More research is needed to determine the effects of MME with mind-motor training in older adults with memory complaints. The objectives of this thesis were to summarize the results from studies published to date regarding effects of MME interventions in cognition and neuroimaging outcomes in older adults without dementia, and to determine whether MME with mind-motor training would benefit cognition, mobility, and neuroimaging outcomes compared to MME alone. A literature review of MME studies in older adults without dementia was conducted, as well as a 24-week exercise program in older adults with memory complaints. Main results were as follows: the literature review suggested that MME may improve cognition and neuroimaging outcomes compared to control groups that do not exercise. These effects, however, were not present when MME was compared to other interventions. The results from the exercise program revealed that 24 weeks of MME with mind-motor training showed trends for greater benefits in overall cognition and memory. These trends were confirmed after 28 weeks of no exercise. For mobility outcomes, MME alone benefited walking measures, but MME with mind-motor training did not seem to impart the same benefits. An exploratory study of memory and neuroimaging revealed that MME and mind-motor training benefited a specific type of memory (i.e., visuospatial), with changes in the connectivity of brain regions involved in motor function, and related to Alzheimer’s disease risk. In conclusion, MME with additional mind-motor training is a promising strategy to improve cognition.
Boa Sorte Silva, Narlon Cassio, "The Effects of Exercise on Cognition, Mobility, and Neuroimaging Outcomes in Older Adults without Dementia" (2020). Electronic Thesis and Dissertation Repository. 6923.
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Available for download on Wednesday, September 01, 2021