On the 'classification' of neurodegenerative disorders:discrete entities, overlap or continuum?


The traditional method of classifying neurodegenerative diseases is based on the original clinico-pathological concept supported by 'consensus' criteria and data from molecular pathological studies. This review discusses first, current problems in classification resulting from the coexistence of different classificatory schemes, the presence of disease heterogeneity and multiple pathologies, the use of 'signature' brain lesions in diagnosis, and the existence of pathological processes common to different diseases. Second, three models of neurodegenerative disease are proposed: (1) that distinct diseases exist ('discrete' model), (2) that relatively distinct diseases exist but exhibit overlapping features ('overlap' model), and (3) that distinct diseases do not exist and neurodegenerative disease is a 'continuum' in which there is continuous variation in clinical/pathological features from one case to another ('continuum' model). Third, to distinguish between models, the distribution of the most important molecular 'signature' lesions across the different diseases is reviewed. Such lesions often have poor 'fidelity', i.e., they are not unique to individual disorders but are distributed across many diseases consistent with the overlap or continuum models. Fourth, the question of whether the current classificatory system should be rejected is considered and three alternatives are proposed, viz., objective classification, classification for convenience (a 'dissection'), or analysis as a continuum.

Divisions: College of Health & Life Sciences > School of Optometry > Optometry
College of Health & Life Sciences > School of Optometry > Optometry & Vision Science Research Group (OVSRG)
College of Health & Life Sciences
College of Health & Life Sciences > School of Optometry > Vision, Hearing and Language
College of Health & Life Sciences > Clinical and Systems Neuroscience
Additional Information: Creative Commons Attribution Non-Commercial Share Alike International 4.0
Publication ISSN: 1509-572X
Last Modified: 29 Nov 2023 10:34
Date Deposited: 30 Nov 2012 10:21
Full Text Link: 10.5114/fn.2012.30521
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
http://www.term ... ,19340,0,1.html (Publisher URL)
PURE Output Type: Article
Published Date: 2012
Authors: Armstrong, Richard A.

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