LeSCoD: a new clinical scale for the detection of Lewy body disease in neurocognitive disorders

Background Dementia with Lewy bodies remains underdiagnosed in clinical practice mainly because of the low sensitivity of existing diagnostic criteria and a strong overlap with Alzheimer’s pathology that can mask the Lewy phenotype. Objective The objective of this study was therefore to develop and validate a new clinical scale designed to detect signs of Lewy body disease, called LeSCoD for Lewy body Screening scale in Cognitive Disorders. Methods 128 patients who fulfilled the clinical criteria of dementia with Lewy bodies (DLB; n = 32), Alzheimer’s disease (AD; n = 77) or both ( n = 19) was prospectively enrolled. 18 F-DOPA PET imaging and/or CSF biomarkers were available in some patients. LeSCoD scale was systematically administered and the potential correlation with 18 F-DOPA PET imaging was evaluated in a subgroup of patients. Results LeSCoD scale showed robust internal and external validity. We determined a cut-off of 10 above which the sensitivity and specificity for Lewy body disease diagnosis were 86% and 95%, respectively. The LeSCoD scale correlated with striatal dopamine uptake in 18 F-DOPA PET. Conclusion LeSCoD scale is a simple and reliable tool for the evaluation of Lewy body disease in routine clinical practice, with a higher sensitivity and specificity than the existing criteria. It might be an alternative to the use of dopamine-specific imaging.