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.