Murray, Melissa E.

AbstractThe relationship between clinicopathologic diagnosis and 123I‐FP‐CIT SPECT in 18 patients with dementia (12 with Lewy body disease) from one center in the United States was assessed. The sensitivity and specificity of abnormal 123I‐FP‐CIT SPECT with reduced striatal uptake on visual inspection for predicting Lewy body disease were 91.7% and 83.3%, respectively. The mean calculated putamen to occipital ratio (mPOR) based on regions of interest was significantly reduced in Lewy body disease compared to non‐Lewy body disease cases (P = 0.002). In this study, abnormal 123I‐FP‐CIT SPECT was strongly associated with underlying Lewy body disease pathology, supporting the utility of 123I‐FP‐CIT SPECT in the clinical diagnosis of dementia with Lewy bodies.

AbstractIntroductionWe sought to assess the individual and combined contribution of limbic and neocortical α‐synuclein, tau, and amyloid β (Aβ) to duration of illness in dementia with Lewy bodies (DLB).MethodsQuantitative digital pathology of limbic and neocortical α‐synuclein, tau, and Aβ was assessed in 49 patients with clinically probable DLB. Regression modeling examined the unique and shared contribution of each pathology to the variance of illness duration.ResultsPatients with diffuse Lewy body disease had more severe pathology of each type and a shorter duration of illness than individuals with transitional Lewy body disease. The three pathologies accounted for 25% of the total variance of duration of illness, with 19% accounted for by α‐synuclein alone or in combination with tau and Aβ. When the diffuse Lewy body disease group was examined separately, α‐synuclein deposition significantly exceeded that of tau and Aβ. In this model, 20% of 24% total variance in the model for duration of illness was accounted for independently by α‐synuclein.DiscussionIn DLB, α‐synuclein is an important predictor of disease duration, both independently and synergistically with tau and Aβ.

Abstract Introduction Comparative transcriptome analyses in Alzheimer's disease (AD) and other neurodegenerative proteinopathies can uncover both shared and distinct disease pathways. Methods We analyzed 940 brain transcriptomes including patients with AD, progressive supranuclear palsy (PSP; a primary tauopathy), and control subjects. Results We identified transcriptional coexpression networks implicated in myelination, which were lower in PSP temporal cortex (TCX) compared with AD. Some of these associations were retained even after adjustments for brain cell population changes. These TCX myelination network structures were preserved in cerebellum but they were not differentially expressed in cerebellum between AD and PSP. Myelination networks were downregulated in both AD and PSP, when compared with control TCX samples. Discussion Downregulation of myelination networks may underlie both PSP and AD pathophysiology, but may be more pronounced in PSP. These data also highlight conservation of transcriptional networks across brain regions and the influence of cell type changes on these networks.