However, there is currently no comprehensive overview synthesizing evidence of missed DLB diagnosis. Therefore, we aimed to identify the proportion of individuals with Lewy pathology that are clinically unrecognised in clinicopathological and emerging in vivo biomarker studies. Therefore, we conducted a narrative literature review to identify studies that included pathological confirmation of Lewy pathology through autopsy or biomarker evidence, and antemortem clinical assessment of dementia subtype. Nine autopsy and three seed amplification assays studies were identified and compared. 

Across ~25 years of clinicopathological research using heterogenous methodologies, DLB remains consistently and substantially under-recognised during life. 50-80% of dementia cases with autopsy-proven Lewy pathology had a missed DLB diagnosis. Seed amplification assay biomarkers applied to cognitively impaired clinical populations generally align with autopsy studies, suggesting that ~67-79% of cases with biomarker-indicated Lewy pathology are not recognised as having Lewy body disease during life.

Several factors may explain under-recognition of DLB, broadly grouped as those attributable to pathology (masking effects of co-pathologies, or clinically silent Lewy pathology) and those attributable to clinical presentation (failure to recognise clinical features of DLB, and misattribution of DLB features to other conditions).

At least 50% of DLB cases are unrecognised, evidenced by both clinicopathological and biomarker findings. This has important implications for prognosis, patient management, and research into both DLB and other dementias. Improved recognition may facilitate more accurate diagnosis, better-targeted care, and more effective development and evaluation of disease-modifying dementia therapies.