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Neuropathologic features associated with Alzheimer disease diagnosis: age matters
L E Middleton1, L T Grinberg, B Miller
1University of Waterloo, Waterloo, Canada. laura.middleton@uwaterloo.ca
Neurology
|October 28, 2011
Summary
Clinical Alzheimer disease (AD) diagnosis is less associated with neurofibrillary tangles in older adults. Neuropathology better differentiates AD in younger individuals, with non-AD pathology improving accuracy across all ages.
Area of Science:
- Neurology
- Gerontology
- Pathology
Background:
- Clinical diagnosis of Alzheimer disease (AD) is crucial for patient care and research.
- Understanding the relationship between clinical AD and postmortem neuropathology is essential for diagnostic accuracy.
- Age-related changes may influence the accuracy of AD diagnosis and its neuropathological correlates.
Purpose of the Study:
- To investigate if the association between clinical AD diagnosis and neuropathology varies by age.
- To determine if neuropathology's precision in differentiating AD from normal cognition changes with age.
Main Methods:
- Cross-sectional analysis of 2,014 older adults from the National Alzheimer's Coordinating Center database.
- Included individuals with clinical diagnosis of normal cognition or AD and postmortem neuropathologic examination.
- Used logistic regression and receiver operating characteristic curves to analyze age-related differences in diagnostic precision.
Main Results:
- The association between clinical AD diagnosis and neurofibrillary tangles weakened with increasing age.
- Neuropathology differentiated clinical AD from normal cognition more precisely in younger age groups (70-84 years) compared to the oldest old (≥85 years).
- Non-Alzheimer disease pathology improved diagnostic precision across all age groups.
Conclusions:
- Clinical AD diagnosis showed a weaker association with neurofibrillary tangles in the oldest old.
- Potential reasons include less accurate clinical diagnosis, neurocompensation, or unmeasured pathology in advanced age.
- Age is a significant factor influencing the relationship between clinical AD diagnosis and neuropathological findings.
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