Abstract BACKGROUND We sought to characterize the cognitive profile among individuals with mild cognitive impairment with Lewy bodies (MCI‐LB) to help guide future clinical criteria. METHODS Systematic review and meta‐analysis included MCI‐LB studies with cognitive data from PubMed, Embase, Web of Science, and PsycINFO (January 1990 to March 2023). MCI‐LB scores were compared to controls, MCI due to Alzheimer's disease (MCI‐AD), and dementia with Lewy bodies (DLB) groups with random‐effects models. RESULTS We included 26 studies and 2823 participants. Across all domains, the MCI‐LB group performed worse than controls and better than DLB. Compared to MCI‐AD, the MCI‐LB group performed worse in attention/processing speed ( g = –0.24, 95% confidence interval [CI]: –0.35, –0.12), attention/executive ( g = –0.42, 95% CI: –0.56, –0.28); better in verbal immediate recall ( g = 0.37; 95% CI: 0.15, 0.59) and delayed memory ( g = 0.40; 95% CI: 0.22, 0.58). DISCUSSION The cognitive profiles in MCI‐LB and MCI‐AD are consistent with established profiles in DLB and AD. Neuropsychological assessment may be helpful in differential diagnosis, even in early disease states. Highlights We performed a systematic review and meta‐analysis for cognition in mild cognitive impairment with Lewy bodies (MCI‐LB). Compared to MCI due to Alzheimer's disease (MCI‐AD), MCI‐LB had worse attention, executive function, and processing speed. Compared to MCI‐AD, MCI‐LB had better verbal immediate and delayed recall. The MCI‐LB group was worse on all cognitive domains than controls, and better than dementia with Lewy bodies. Studies used different tests and there is a need for global efforts for harmonization.
Neuropsychological test performance in mild cognitive impairment with Lewy bodies: a meta‐analysis
AbstractBackgroundProdromal dementia with Lewy bodies (DLB) research criteria were recently published and further work is needed to characterize the neuropsychological profile and refine clinical criteria. We performed a meta‐analysis to compare the cognitive performance of mild cognitive impairment with Lewy bodies (MCI‐LB) groups to controls, MCI due to Alzheimer’s disease (MCI‐AD), and DLB.MethodFollowing PRISMA guidelines, we searched the literature for 1) English‐language studies on MCI‐LB; 2) published January 1990‐March 2023, 3) with ≥1 standardized cognitive measure; and 4) comparison data from controls, MCI‐AD, and/or DLB. Pooled means with 95% confidence intervals were calculated for demographics. Effect sizes were calculated for group comparisons on cognitive domains. Random effects meta‐analysis models were used for group comparisons.ResultThere were 3440 participants from 27 studies across 10 countries. Mean age did not differ between groups. The percentage of female subjects was lower in the MCI‐LB group than the MCI‐AD group. Mean years of education for the MCI‐LB group was lower than the controls, but similar to MCI‐AD and DLB groups (Table 1). Compared to controls, the MCI‐LB group had lower scores for the global screening, executive function, visuospatial, language, learning, and memory domains. Compared to MCI‐AD, MCI‐LB performed better on learning and delayed recall, but similarly across other domains. Compared to DLB, MCI‐LB had better scores for global screening, executive function, language, and delayed recall (Table 2). Recognition for MCI‐LB vs. MCI‐AD; visuospatial, learning, and recognition for MCI‐LB vs. DLB could not be assessed, as fewer than 3 studies reported this data.ConclusionCognitive measures can help differentiate MCI‐LB from controls and DLB. Neuropsychological measures of learning and memory may be required to discriminate MCI‐LB from MCI‐AD in clinical practice but global screening measure scores appear insufficient in this regard. High heterogeneity across MCI‐LB studies highlights the need for harmonized neuropsychological research protocols.