Final answer:
The pathology of Alzheimer's Dementia on MRI includes neurodegeneration, visible brain shrinkage, and loss of neurons, especially in the hippocampus. Abnormal amyloid plaques and neurofibrillary tangles made of tau protein are distinctive markers. These changes lead to reduced metabolic activity and synapse loss between neurons.
Step-by-step explanation:
The pathology of Alzheimer's Dementia as seen on MRI includes identifiable changes such as neurodegeneration, particularly within the ventricles and the hippocampus. This degeneration is visually appreciable as an overall shrinking of brain volume. Characteristics of Alzheimer's include abnormal accumulations called amyloid plaques between brain cells and neurofibrillary tangles, which are composed of tau protein, inside of neurons. These pathological hallmarks contribute to the cognitive symptoms associated with Alzheimer's. On molecular and cellular levels, these changes are linked to loss of synapses between neurons and subsequent neuronal death.
Additionally, compared to a normal brain, an MRI image of a brain affected by Alzheimer's shows less metabolic activity, noticeable as fewer red and orange areas, and an overall decrease in brain volume. The formation of amyloid plaques, neurofibrillary tangles, and the severe loss of neurons, especially in the hippocampus, are primary indicators on an MRI that a patient may have Alzheimer's disease.