Relationship between clinical symptomatology and disease burden in dementia with Lewy bodies: An overview of the DEvELOP baseline results

Background Dementia with Lewy Bodies (DLB) is a heterogeneous disease with a highly variable presentation of core and suggestive symptoms. The relationships between these symptoms and their impact on disease burden remain unclear. The DEmentia with LEwy BOdies Project (DEvELOP) is a longitudinal cohort study that aims to phenotype DLB patients in depth and study the course of symptoms and biomarkers over time. Here, we provide an overview of our baseline results. Additionally, we investigated associations between core and suggestive features and different aspects of disease burden, i.e. instrumental activities of daily living (I‐ADL) functioning, quality of life (QoL) and caregiver burden. Method DEvELOP is a prospective cohort study conducted at Alzheimer Center Amsterdam. To date, we included 94 DLB patients (69±6yrs, 11%F, MMSE 25±3), who underwent extensive clinical assessment, including assessment of core features, neurological examination, neuropsychological examination, MRI(n=87), EEG(n=65), DAT‐SPECT(n =75) and CSF(n=71). Core features (hallucinations, parkinsonism, fluctuations, RBD) and suggestive features (autonomous dysfunction, neuropsychiatric symptoms) were assessed using standardized questionnaires. We evaluated how each of these features related to the functional activities questionnaire(FAQ), QoL(QoL‐AD), and caregiver burden(ZARIT), using linear regression analyses with backwards selection, adjusted for age, sex and MMSE. Result In the DEvELOP cohort, 19% of patients had all four core features, while 11% had merely had one (Figure 1). RBD was most frequently reported feature (75%). 87% had an abnormal DAT‐spect, 95% showed diffuse abnormalities on EEG. Abnormal CSF Aβ42 was found in 49%, abnormal CSF p‐tau in 42%. More severe fluctuations on the Clinical Assessment of Fluctuations (stβ=0.46, p <0.001) and lower MMSE (stβ=‐0.31, p =0.002) were independent determinants of higher FAQ‐scores. More depressive symptoms on GDS (stβ=‐0.51, p <0.001) and more severe obstipation(stβ=‐0.22, p =0.01) were independently associated with lower QoL‐AD‐scores. Last, NPI‐apathy associated with higher caregiver burden on ZARIT (stβ=0.49, p <0.001) (Table 1, Figure 2). Conclusion We deeply phenotyped our prospective cohort of DLB patients and found clinically relevant associations between symptoms and disease burden. Cognitive symptoms were related to lower I‐ADL functioning, while negative psychiatric symptoms were associated with lower QoL and higher caregiver burden. Follow‐up is currently collected to further study the course of symptoms over time.