Do fine motor impairments constitute a key feature of mild cognitive impairment? A systematic review and meta‐analysis

Abstract

AbstractBackgroundTypical symptoms of mild cognitive impairment (MCI) include impairments in memory, executive function, and visuospatial skills. While impairments in these cognitive domains are highly apparent after MCI, impairments in motor domain are not so conspicuous. Converging evidence suggests that individuals with MCI demonstrate motor impairments in lower extremity such as reduced balance and impaired gait performance. However, the impact of MCI on upper extremity motor impairments is not well understood. In the current meta‐analysis, we examine whether fine motor impairments are a key feature of mild cognitive impairment.MethodWe performed a systematic search of electronic databases for articles published between 1990 and 2019. The meta‐analysis included studies that compared healthy older adults and adults with a clinical diagnosis of MCI on fine motor tasks such as handwriting, finger tapping, and hand dexterity.ResultTen studies with over 800 participants qualified for inclusion. Rigorous meta‐analytic techniques using random effects model, forest and funnels plots revealed a standardized mean difference effect of 0.48 (95% CI = 0.77 to 0.19, p=0.001). This moderate effect indicated deficits in fine motor control are a likely feature of MCI.ConclusionThe cumulative evidence suggests that fine motor impairments are pervasive in MCI across a range of upper extremity motor tasks. Quantitative assessment of the decline in fine motor function in MCI may be promising approach to understand the changes in motor function that occur with the onset of Alzheimer’s disease and are clearly differentiated from normal aging‐related decline.