Clinical Validity of A[latin sharp s]-Protein Deposition Staging in Brain Aging and Alzheimer Disease.
GOLD, GABRIEL MD; KOVARI, ENIKO MD; CORTE, GINA MD; HERRMANN, FRANCOIS R. MD, MPH; CANUTO, ALESSANDRA MD; BUSSIERE, THIERRY PhD; HOF, PATRICK R. MD; BOURAS, CONSTANTIN MD; GIANNAKOPOULOS, PANTELEIMON MD
Journal of Neuropathology & Experimental Neurology.
60(10):946-952, October 2001.
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Braak's neurofibrillary tangle (NFT) pathology staging system of Alzheimer disease (AD) correlates generally with clinical data. Recently, Braak's group proposed an A[latin sharp s]-protein staging based on the progression of amyloid deposition in the medial temporal lobe. To examine its clinical validity and evaluate whether it adds predictive power to NFT-based staging, we performed a study comparing both neuropathological classifications with clinical dementia rating scale (CDR) scores in a large autopsy series. The 2 neuropathological staging systems were strongly correlated. Their association with clinical severity was highly significant. However, the strength of the relationship was greater for NFT-based staging. It accounted for 26.5% of the variability in clinical severity, A[latin sharp s]-protein-based staging for 13.0%, and age for 4.4%. Compared to NFT-based staging, the A[latin sharp s]-protein-based system was less able to distinguish mild cognitive changes from dementia and showed marked overlap among the various stages of cognitive decline. In a multivariate model, NFT and age together accounted for 27.2% of the clinical variability and the addition of A[latin sharp s]-protein deposition staging could only explain an extra 2.9%. Our data support the close relationship between NFT progression and amyloid formation within the medial temporal lobe proposed by Braak's group but demonstrate the limited value of A[latin sharp s]-protein deposition staging in terms of clinicopathological correlations.
(C) 2001 American Association of Neuropathologists, Inc