How Exercise Influences Cognitive Performance When Mild Cognitive Impairment Exists: A Literature Review

Abstract

Older adults who present with mild cognitive impairment (MCI) have an increased risk of developing more advanced dementia. However, no pharmacological treatment currently exists to slow the progression of or reverse MCI. The purpose of the current systematic review is to summarize evidence surrounding the impact of exercise interventions on the cognitive performance levels of community-dwelling older adults with MCI. Computerized database and ancestry search strategies located distinct intervention trials between 1990 and 2015. Results indicated that physical exercise may benefit cognitive function among older adults who have MCI, including improvements in global cognition, executive function, memory, attention, and processing speed. Physical exercise may also positively impact the physiology of the aging brain. However, evidence surrounding the characteristics of effective physical exercise interventions in terms of exercise type, intensity, duration, and frequency remains limited.

The Efficacy of Cognitive Intervention in Mild Cognitive Impairment (MCI): a Meta-Analysis of Outcomes on Neuropsychological Measures

“… Buschert et al ( 2011 ) RCT, single-blind, active control n = 43 aMCI n = 27 mild AD n = 16 Tx n = 10 Cntl n = 12 Age: =71.2 s = 7.0 • 11 session minimum - 20 “units”, 120 min/ week • Group-based, multicomponent cognitive intervention including memory, cognitive stimulation, face-name association, errorless learning, principles of meta-cognition, education ADAS-cog, MMSE, TMT B, RBANS, story recall, MADRS, QoL-AD • Significant interaction between treatment and progression for ADAS-Cog (F = 6.2, p = 0.02, η2 = 0.26), MMSE (F = 3.8, p = 0.07, η2 = 0.17), RBANS story memory (F = 3.4, p = 0.08, η2 = 0.16) and TMT = B (F = 3.5, p = 0.08, η2 = 0.16) • Main effects for treatment were found for MMSE (F = 8.5, p < 0.01, η2 = .23), RBANS story memory (F = 12.5, p < 0.01, η2 = 0.41) and RBANS Story recall (F = 9.9, p < 0.01, η2 = 0.36) • ↑ in global cog status, and specific cog and non-cog functions • aMCI demonstrate significant change in ADAS-Cog scores • aMCI subjects demonstrated tendency toward higher attentional skills demonstrated by TMT-B • No significant effect on memory performance compared to active controls 0.661 5. Carretti et al ( 2013 ) RCT, active control n = 20 (aMCI) Tx n = 10 Cntl n = 10 Age: Tx: = 71.8 s = 2.20 Cntl: = 70.6 s = 2.63 • 5, 90 min sessions • Individual-based, one-on-one sessions using restorative strategies which focused on working memory techniques NPE, Vocab, CWMS, DS-FWD; DS-BWD, Dot matrix, List recall, Pattern comparison, Cattell test • Significant effect post training in CWMS (3.8), Dot Matrix (2.3), Cattell test (0.50) vs control CWMS (0.60), Dot Matrix (2.3), Cattell test (−0.40). P -values for these tests where groups improved by 1 SD are <0.01, <0.05, and <0.05, respectively • Verbal working memory training is a promising approach to sustaining memory function in aMCI • Working memory training showed transfer to some cognitive components of memory part of the core cognitive impairments responsible for MCI → AD −0.713 6.…”

“…Test for heterogeneity Q = 205.409, df = 25; p = 0.000; I 2 = 87.829; τ 2 = 0.484 Intervention Effects – By Cognitive Domain : Please see Table 3 for a breakdown by domain including the study, outcome measures, effect sizes, indices of heterogeneity, and prediction intervals. Table 3 Effect sizes by cognitive domain: Effects of outcome measures, confidence intervals and prediction intervals Cognitive domain Study Measure n g Actual/ observed intervals p Q df ( Q ) p I 2 τ 2 τ Prediction intervals Lower (95%) Upper (95%) Lower (95%) Upper (95%) Mental status/ general cognitive Barban et al ( 2016 ) MMSE 106 0.111 −0.271 0.493 0.569 Barnes et al ( 2009 ) RBANS Total 36 0.374 −0.272 1.020 0.256 Buschert et al ( 2011 ) Combined (MMSE + ADAS-Cog) 22 0.387 −0.514 1.288 0.400 Carretti et al ( 2013 ) Cattell – CFT 20 0.818 −0.059 1.695 0.068 ...…”

“…nutrition, exercise, etc.) are aggressively being sought to mitigate or slow illness progression (Cai and Abrahamson 2016 ; Curlik and Shors 2013 ; Kivipelto et al 2013 ; Lehert et al 2015 ; Simons et al 2016 ; Smith et al 2010 ). This may be especially important as cognitive training in MCI has been associated with increased activation in the hippocampus (Hampstead et al 2012b ; Rosen et al 2011 ), right inferior parietal lobe (Belleville et al 2011 ), frontoparietal network (Hampstead et al 2011 ), occipito-temporal areas (Onur et al 2016 ), and implicated in other processes (Barban et al 2017 ; Ciarmiello et al 2015 ; Maffei et al 2017 ).…”

Mild cognitive impairment: A concept analysis

“…AAN recommends that exercise training and cognitive training may help to improve cognitive measures . Studies suggest that nonpharmacological interventions such as physical exercise, playing musical instruments, dance, Tai‐chi, computerized cognitive training and cognition‐based intervention, enhance global cognitive function, attention, executive function, processing speed, and delayed memory …”

Four-Week, Home-Based, Robot Cognitive Intervention for Patients with Mild Cognitive Impairment: a Pilot Randomized Controlled Trial

“… 2 Therefore, recent studies have focused on multiple non-pharmacological strategies to mitigate the progression to dementia in patients with MCI, including cognitive intervention or lifestyle changes (i.e., exercise). 3 4 …”