Related Experiment Video
Updated: Jun 22, 2026
08:29
Symmetric Bihemispheric Postmortem Brain Cutting to Study Healthy and Pathological Brain Conditions in Humans
Published on: December 18, 2016
Age, neuropathology, and dementia.
George M Savva1, Stephen B Wharton, Paul G Ince
1Department of Public Health and Primary Care, Institute of Public Health, University of Cambridge, Cambridge, United Kingdom.
The New England Journal of Medicine
|May 29, 2009
Summary
Alzheimer's disease pathology links to dementia weaken with advanced age. Cerebral atrophy remains a consistent dementia indicator across age groups, impacting intervention strategies for older populations.
Area of Science:
- Neurology
- Gerontology
- Pathology
Background:
- Alzheimer's disease (AD) research often overlooks the very old.
- Studies in the oldest adults show weaker links between AD pathology and dementia.
- This suggests age significantly modifies AD's neuropathological presentation.
Purpose of the Study:
- To investigate how age affects the relationship between AD neuropathological features and dementia.
- To compare the influence of AD pathology versus cerebral atrophy on dementia across different age groups.
Main Methods:
- Examined 456 brains from the Medical Research Council Cognitive Function and Ageing Study (ages 69-103).
- Utilized a standard neuropathological protocol assessing AD features, cerebral atrophy, and cerebrovascular disease.
- Employed logistic regression to analyze the effect of age on the association between neuropathology and dementia.
Main Results:
- The association between AD pathology (e.g., neuritic plaques) and dementia decreased significantly with age.
- For example, the odds ratio for plaques and dementia dropped from 8.63 at 75 to 2.48 at 95.
- Conversely, neocortical cerebral atrophy consistently correlated with dementia across all ages studied.
Conclusions:
- The link between Alzheimer's disease pathology and dementia is less pronounced in the oldest individuals.
- Cerebral atrophy serves as a more reliable indicator of dementia in very old adults.
- Age is a critical factor to consider when evaluating the population-level impact of dementia interventions.
Related Concept Videos
01:29Alzheimer Disease l: Introduction
Alzheimer disease is a chronic, progressive, and irreversible neurodegenerative disorder and the most common cause of dementia in older adults. It leads to gradual neuronal loss, causing cognitive decline, behavioral changes, and loss of functional independence.Risk Factors and EtiologyThe disease is multifactorial. Age is the strongest risk factor, with prevalence doubling every 5 years after age 65. Genetic factors include mutations in genes such as APP, PSEN1, and PSEN2, which are associated...
01:22Dementia l: Introduction
Dementia is an acquired, progressive syndrome characterized by a decline in multiple cognitive domains severe enough to impair daily functioning and reduce independence. Although memory loss is a central feature, the diagnosis requires additional deficits involving language, executive function, visuospatial skills, judgment, calculation, or abstract reasoning. These cognitive impairments reflect underlying neurodegenerative or vascular processes that gradually disrupt neuronal networks...
01:26Alzheimer's Disease: Overview
Alzheimer's Disease (AD) is a continually advancing neurodegenerative disorder, distinguished by escalating memory loss, cognitive dysfunction, and dementia. The disease unfolds in three stages: preclinical, mild cognitive impairment (MCI), and dementia. Its onset is insidious, and the progression gradual, with the cause not well explained by other disorders.
The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau...
The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau...
01:23Alzheimer Disease ll: Pathophysiology
Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal...
01:30Dementia
Dementia is a collective term for cognitive disorders primarily affecting memory, thinking, and reasoning. It is not a specific disease but a syndrome, with Alzheimer's disease being the most common cause, accounting for approximately 60-80% of cases. Other types include vascular dementia, Lewy body dementia, and frontotemporal dementia. Dementia affects millions worldwide, particularly older adults, though it is not a normal part of aging.
The progression of dementia is generally gradual.
The progression of dementia is generally gradual.
01:22Diabetic Neuropathy
DefinitionDiabetic neuropathy is nerve damage caused by long-standing diabetes mellitus. It results directly from prolonged high blood sugar levels.PathophysiologyThe pathophysiology of diabetic neuropathy involves both metabolic and vascular disturbances triggered by chronic hyperglycemia.Metabolic injury: Elevated glucose levels activate the polyol pathway within nerve cells, leading to the accumulation of sorbitol and fructose. This increases oxidative stress, disrupts normal nerve...