Heterogeneity of dementia with lewy bodies: Insights from clinical presentations, neuropathology, and biomarkers.

BACKGROUND: Dementia with Lewy Bodies (DLB) is a neurodegenerative disorder characterised by α-synuclein pathology, causing cognitive decline, motor and non-motor symptoms. This review explores the clinical and neuropathological heterogeneity of DLB, which complicates its early diagnosis, prognosis, and treatment. The staging of Lewy body (LB) pathology varies, with both brain-first and body-first hypotheses suggesting different origins and pathways for disease progression. Co-pathologies, such as amyloid-β plaques, tau tangles, and cerebrovascular changes, further influence the clinical presentation and rate of disease progression in DLB patients, contributing to significant variability. In this review, the role of genetic factors, particularly APOE ε4 and GBA mutations, in shaping DLB's clinical and pathological diversity is also emphasized. Heterogeneous manifestations, including REM sleep behavior disorder (RBD), mild cognitive impairment, and psychiatric-onset DLB, highlight the need for improved biomarkers to guide early diagnosis. Neuroimaging techniques such as [18F]FDG PET and [123I]FP-CIT SPECT help distinguish DLB from other dementias, like Alzheimer's disease (AD), though challenges remain in identifying co-pathologies with precision. CONCLUSION: Overall, the paper explores the complexity of DLB's heterogeneous nature, advocating for deeper exploration of its diverse pathological pathways, genetic predispositions, and clinical profiles to improve diagnosis and treatment outcomes. Understanding this heterogeneity is crucial for the development of personalized therapeutic strategies and effective management of the disease.