Alzheimer’s disease (AD) is a degenerative disorder of the brain that is manifested by dementia and progressive physiological impairment. It is the most common cause of dementia in the elderly but is not a normal part of aging. More than 4 million Americans suffer from AD.
Dementia involves progressive decline in two or more of the following areas of cognition: memory, language, calculation, visual-spatial perception, judgment, abstraction, and behavior. Dementia of the Alzheimer’s type (DAT) accounts for approximately half of all dementias. The average time from onset of symptoms to death is 8 to 10 years.
The pathophysiological changes that occur in DAT include the following:
• Presence of neurofibrillary tangles, neuritic plaques, and amyloid angiopathy
• Accumulation of lipofuscin granules and granulovacuolar organelles in the cytoplasm of the neurons
• Structural changes in the dendrites of the neurons and in the cell bodies
• Predominant neuronal degeneration in the cortical association areas of the basal ganglia
• Gross cortical atrophy and widening of the sulci.
• Enlargement of the ventricles
• Decrease in neurotransmitters (acetylcholine, dopamine, norepinephrine, serotonin), somatostatin, and neuropeptide substance P