Preventing Loss of Independence through Exercise (PLIE): A Pilot Trial in Older Adults with Subjective Memory Decline and Mild Cognitive Impairment

Background: Preventing Loss of Independence through Exercise (PLIE) is a group movement program initially developed for people with mild-to-moderate dementia that integrates principles from several well-established traditions to specifically address the needs of people with cognitive impairment. Objective: To investigate whether PLIE would benefit cognitive and behavioral outcomes and functional brain connectivity in older adults with milder forms of cognitive impairment. Methods: Participants (>= 55 y) with subjective memory decline (SMD) or mild cognitive impairment (MCI) were assessed with tests of cognitive and physical function, self-report questionnaires, and resting state functional magnetic resonance imaging (rs-fMRI) on a 3 Tesla scanner before and after participating in twice weekly PLIE classes for 12 weeks at the San Francisco Veterans Affairs Medical Center. Results: Eighteen participants completed the pre-post intervention pilot trial. We observed significant improvements on the Alzheimer's Disease Assessment Scale cognitive subscale (ADAS-cog; effect size 0.34, p = 0.002) and enhanced functional connections between the medial prefrontal cortex (mPFC) and other nodes of the default mode network (DMN) after PLIE. Improvements (i.e., lower scores) on ADAS-cog were significantly correlated with enhanced functional connectivity between the mPFC and left lateral parietal cortex (Spearman's rho = -0.74, p = 0.001) and between the mPFC and right hippocampus (Spearman's rho = -0.83, p = 0.001). After completing PLIE, participants reported significant reductions in feelings of social isolation and improvements in well-being and interoceptive self-regulation. Conclusion: These preliminary findings of post-PLIE improvements in DMN functional connectivity, cognition, interoceptive self-regulation, well-being and reduced feelings of social isolation warrant larger randomized, controlled trials of PLIE in older adults with SMD and MCI.