Session Time: 1:45pm-3:15pm
Location: Les Muses Terrace, Level 3
Objective: Present the validation of the new proposed novel staging system (NSS) for Lewy body disease and compare it against the previously proposed staging systems.
Background: Several staging criteria have been previously proposed for the neuropathological classification of cases with deposition of α-synuclein in the form of Lewy related pathology (LRP). The previously developed neuropathological staging criteria, like the 2005 Newcastle-McKeith Dementia with Lew bodies (DLB) criteria and the 2003 Braak LRP staging system, led to a large number of cases not being classified when applied to a varied sample of neuropathological cases with LRP and to some cases fitting more than one category in some instances.
Method: We uploaded scanned slide images for 34 cases to an online server. Nine regions were included and a panel of 18 international experts semi-quantitatively rated each of the slides and classified each case based on the Newcastle-McKeith DLB 2005 third report criteria, the Braak 2003 criteria, the Leverenz 2008 criteria, the Unified Staging System criteria and the new proposed NSS to these cases. Multiple inter-rater agreement was estimated Cronbach α and confidence intervals were bootstrapped. In addition, we retrospectively applied the criteria to a sample of 204 cases with LRP to evaluate the percentage of cases not classified by each of the systems in a large representative sample of cases from a clinical brain bank.
Results: Inter-rater agreement for semi-quantitative scores for each of the evaluated areas mostly fell between the 0.70 and 0.80 range. Median percentage of unclassified cases in the prospective sample was 0% for the NSS, whereas for the other staging systems it ranged between 3-26%. In the retrospective analysis all cases were also classified by the NSS, whereas for the other staging systems up to 58.3% of the cases were not classified. The NSS also achieved one of the highest inter-rater agreements for the classification into the different staging systems.
Conclusion: The new criteria classified showed overall the best combination of classification of cases and inter-rater agreement of all the available LRP classification systems. They are also based on a dichotomous evaluation of the pathology, which simplifies the rating procedure. All these characteristics make the proposed system an easy implementable and reliable system to evaluate LRP in future studies.
To cite this abstract in AMA style:J. Toledo, L. Walker, J. Trojanowski, I. Mckeith, J. Attems. New Neuropathological Staging System for Lewy Body Disease [abstract]. Mov Disord. 2019; 34 (suppl 2). https://www.mdsabstracts.org/abstract/new-neuropathological-staging-system-for-lewy-body-disease/. Accessed November 29, 2023.
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