Abstract
INTRODUCTION: The misdiagnosis rate of Dementia with Lewy Bodies (DLB) remains high. Accurate diagnosis is paramount in the era of anti-amyloid therapy. The main objective of the current study is to elucidate early clinical features of pathologically confirmed DLB without parkinsonism (DLB-nP) that potentially resemble Alzheimer's disease (AD). METHODS: We accessed the National Alzheimer's Coordinating Center database from 2005 to December 2022 data freeze and included 3159 Alzheimer's disease, 91 DLB-nP, and 307 DLB with parkinsonism (DLBP) cases. Diagnosis of AD and DLB were based on existing pathological criteria. First visit data was analyzed. RESULTS: Clinician-determined memory impairment is common in DLB-nP (87.9 % vs. AD 97.4 %) but is associated with a higher risk of AD diagnosis. Misdiagnosis as AD in DLB-nP stands at 75.8 %. Visual hallucinations (VH) or hallucinations are the only variables favoring DLB-nP diagnosis, but they only account for 22 % and 14 % of the cohort, respectively. After patients with VH were removed from the model, the misdiagnosis rate as AD increased to 85.2 %, and nighttime behavior was the only variable found to favor DLB-nP diagnosis. Visuospatial dysfunction is more common in DLB-P than DLB-nP but does not distinguish DLB-nP from AD. CONCLUSION: Amnestic presentation, while favoring AD diagnosis, is common in DLB without parkinsonism, and misdiagnosis is common. While VH remains the most prominent clinical feature for prompting DLB diagnosis, misdiagnosis becomes more profound in its absence during the early phase. In this study, exercising great caution during clinical assessment appears to be the fundamental way to minimize misdiagnosis for patients with amnestic presentation yet without parkinsonism and VH.