ABSTRACT
Alzheimer's disease (AD) is the most common form of dementia in elderly individuals.
Although the diagnosis of AD requires pathological confirmation, several common clinical
features of AD have been identified. These include insidious onset, gradual progression,
medial temporal atrophy, temporoparietal hypoperfusion, early and prominent deficits
in episodic memory and mental tracking, and later deficits in semantic memory. These
characteristic features of AD have enabled excellent in vivo diagnostic sensitivity.
It has become increasingly clear, however, that AD is a heterogeneous disorder. The
left and right cerebral hemispheres can be affected to varying degrees, and variability
on the anterior-posterior axis has also been reported. AD can also present as a focal
degenerative disease, and clinicians must be aware that there may be diagnostic overlap
between AD, primary progressive aphasia, posterior cortical atrophy, corticobasal
degeneration, and frontotemporal dementia.
KEYWORD
Alzheimer's disease - primary progressive aphasia - frontotemporal dementia - posterior
cortical atrophy - focal variants - corticobasal degeneration
