Dementia with Lewy bodies clinical syndrome (DLBCS) questionnaire: A simple tool for the clinical screening of DLB

Abstract

Background

Dementia with Lewy bodies (DLB) remains underdiagnosed due to overlapping clinical features with Alzheimer's disease (AD) and vascular cognitive impairment (VCI). Early recognition is crucial, as DLB has distinct prognostic and therapeutic implications.

Objective

This study aimed to develop and validate a brief, clinically applicable screening instrument to improve bedside recognition of DLB and to compare its performance with established diagnostic approaches.

Methods

We designed the Dementia with Lewy Bodies Clinical Screening Questionnaire (DLBCSQ) and an extended version (DLBCSQ11) incorporating additional items to differentiate DLB from VCI. Clinical data were collected from a dementia registry in Taiwan, including patients with AD, VCI, and DLB. The diagnostic accuracy of DLBCSQ versions was evaluated using receiver operating characteristic (ROC) analyses across subgroups, including mild cognitive impairment with Lewy bodies (LB-MCI).

Results

Both DLBCSQ and DLBCSQ11 demonstrated strong discriminatory ability, with area under the curve (AUC) values exceeding 0.84 for differentiating DLB from non-DLB syndromes. DLBCSQ11 showed greater specificity for distinguishing DLB from VCI, though about 20% of VCI patients still exhibited DLB-like features. Supplementary questions on visual hallucinations and tremors further improved detection of prodromal or mixed DLB cases.

Conclusions

The DLBCSQ9 and DLBCSQ11 represent practical and effective tools for clinical and bedside identification of DLB. By improving early recognition and differentiation from AD and VCI, these instruments may facilitate timely diagnosis, guide treatment decisions, and support future research on mixed dementia syndromes.