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Prevalence of mixed pathologies in the aging brain
Jasmin Rahimi1, Gabor G Kovacs1
1Institute of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria.
Alzheimer'S Research & Therapy
|November 25, 2014
Summary
Mixed brain pathologies, including Alzheimer's and Lewy body diseases, are common in aging brains. Understanding these complex combinations is crucial for diagnosing cognitive decline and developing effective treatments.
Area of Science:
- Neuropathology
- Neurodegenerative Diseases
- Gerontology
Background:
- Alzheimer's disease (AD)-related pathology often co-occurs with other neurodegenerative proteinopathies.
- The prevalence of non-AD proteinopathies is increasingly recognized in both symptomatic and asymptomatic individuals, especially the elderly.
- Evolving diagnostic criteria and varied methodologies in autopsy studies necessitate a review of mixed brain pathologies.
Purpose of the Study:
- To review the prevalence of mixed brain pathologies in recent community-based neuropathology studies.
- To summarize the co-occurrence rates of various pathologies, including Alzheimer's disease, Lewy body pathology, vascular pathology, and TDP-43 proteinopathy.
- To highlight the implications of complex pathologies for disease prognosis, biomarker development, and therapeutic strategies.
Main Methods:
- Systematic review of recent community-based autopsy studies.
- Analysis of reported frequencies for Alzheimer's disease-related pathology, Lewy body pathology, vascular pathologies, TDP-43 proteinopathy, and hippocampal sclerosis.
- Inclusion of data irrespective of clinical symptoms to reflect overall brain pathology prevalence.
Main Results:
- Alzheimer's disease pathology frequency ranges from 19-67%.
- Lewy body pathology occurs in 6-39%, vascular pathologies in 28-70%, and TDP-43 proteinopathy in 13-46% of cases.
- Mixed pathologies are found in 10-74% of brains, with increasing combinations in aging individuals. White-matter pathologies may exceed 80%.
Conclusions:
- Community-based studies reveal complex constellations of pathologies contribute to cognitive decline.
- The aging brain exhibits an increasing number of pathological combinations.
- Findings impact prognosis prediction, biomarker and therapeutic target development, and patient cohort stratification for research and clinical trials.
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