Chin KS, Yassi N, Churilov L, et al. - Given that Alzheimer disease neuropathologies (amyloid-β and tau) frequently co-exist to varying degrees in Lewy body dementias (LBD), which involve dementia with Lewy bodies (DLB) and Parkinson disease dementia (PDD), researchers conducted this systematic review and meta-analysis to examine the prevalence of tau in DLB and PDD, and its connections with clinical outcomes. The inclusion requirements for data extraction were met by 48 articles. According to results, braak neurofibrillary tangle stage ≥ III was noted in 66% of DLB and 52% of PDD at autopsy. Findings suggested an association of higher tau burden in DLB with reduced likelihood of manifesting visual hallucinations and motor parkinsonism, lower diagnostic accuracy of DLB during life and worse cognition before death. Tau is prevalent in LBD and may decrease the precision of clinical diagnosis in people with DLB. Prospective longitudinal studies are required to clarify the functions of co-morbid neuropathologies in Lewy body dementias.