Prevalence and incidence of dementia with Lewy bodies using current McKeith diagnostic criteria (2017–2020): a population-based study

Abstract

Dementia with Lewy bodies (DLB) is one of the most common neurodegenerative dementias in older adults but remains frequently underdiagnosed in routine clinical practice. Epidemiological data are limited and heterogeneous, and only a small number of population-based studies have applied the most recent diagnostic criteria. This study aimed to estimate the prevalence and incidence of DLB using the updated McKeith 2017/2020 criteria and to characterize the clinical profile of affected individuals in a well-defined population. We conducted a population-based prevalence and incidence study of DLB in San Vicente del Raspeig (Spain). Probable DLB cases were identified using the McKeith 2017/2020 diagnostic criteria. The prevalence day was October 18, 2022, and the incidence period covered the previous 12 months. Demographic variables, core clinical features, biomarkers, neuropsychiatric symptoms, and Global Deterioration Scale (GDS) scores were recorded for all prevalent cases. Among 11,445 residents aged ≥ 60 years, 77 prevalent cases of probable DLB were identified (60 dementia-stage and 17 prodromal DLB), corresponding to a prevalence of 6.7 per 1000 individuals (95% CI 5.23–8.23; 0.67%). The annual incidence was 3.2 per 1000 person-years (95% CI 2.19–4.27). Both prevalence and incidence increased with age and were higher in women. Parkinsonism (77%), visual hallucinations (58%), and REM sleep behavior disorder (57%) were the most frequent core clinical features. Neuropsychiatric symptoms other than complex visual hallucinations were present in 64.9% of patients. This population-based study provides updated epidemiological data on DLB using current diagnostic criteria and including prodromal stages. The observed incidence was higher than that reported in previous population-based studies, possibly reflecting differences in diagnostic criteria, case ascertainment, and recognition of prodromal disease and suggesting that the burden of DLB may have been underestimated. These findings highlight the need for improved clinical recognition of DLB in routine practice particularly in early and prodromal stages.