Aging and Alzheimer's disease pathology

Area of Science:

• Neuropathology
• Neuroscience
• Gerontology

Background:

• Dementia prevalence is rising globally, projected to reach 131.5 million by 2050.
• Alzheimer's disease (AD) neuropathology is characterized by senile plaques and neurofibrillary tangles.
• Brain atrophy affects key regions including the entorhinal cortex, hippocampus, and neocortex.

Purpose of the Study:

• To elucidate the neuropathological basis of dementia, using Alzheimer's disease as a model.
• To highlight the relationship between protein deposition, brain atrophy, and clinical presentation in AD.
• To aid neurologists in understanding AD and differentiating it from mimic conditions.

Main Methods:

• Review of established neuropathological hallmarks of Alzheimer's disease.
• Discussion of Braak's staging of tau pathology progression.
• Comparative analysis of neuropathological findings versus clinical symptoms.

Main Results:

• Amyloid-beta and tau depositions, along with brain atrophy, are key AD neuropathological markers.
• Tau pathology spread correlates with disease progression, but does not entirely explain clinical variability.
• A discrepancy exists between neuropathological findings and observed clinical symptoms in AD.

Conclusions:

• Understanding AD neuropathology, including protein aggregation and atrophy, is vital for dementia research.
• Neuropathological findings alone cannot fully account for the clinical spectrum of Alzheimer's disease.
• This review provides insights into age-related brain changes, AD, and conditions that mimic AD for non-expert neurologists.