| Alzheimer Disease Alzheimer disease (AD) is the most common cause of dementia in western
civilization. It affects more women than men, and the clinical course generally lasts
approximately five years. The younger the individual is at the onset of the disease,
the more severe the deficits for the patient. One famous contemporary who suffers
from the disease is former U.S. President Ronald Reagan.
The cerebral cortex and some other forebrain regions atrophy so
severely that the brain may weigh less than 1000g at death. Shrinkage is most pronounced
in the frontal and temporal lobes. The insula and the medial part of the temporal
lobe tend to demonstrate the highest number of neuritic plaques. The greater
the number of plaques the higher the degree of dementia. The disease often causes
vacuolization of the subpial layers of the temporal and parietal lobes. The spongy
state is associated with neuronal loss and is similar to the effects of Creutzfeldt-Jakob
disease.
Researchers continue to search for causes and cures for AD.
The gene that codes for the B-amyloid protein located on chromosome 21 is implicated in
the 20% of patients for whom there is a family history of AD. Head injury has
been implicated in 3 to 5 % of AD cases. There is a 70 to 90% decrease in the
production of the enzyme that makes acetylcholine. Other neurotransmitter
abnormalities have also been implicated.
For more information concerning Alzheimer Disease
please visit the web-site below.
More on Alzheimer Disease
Back to temporal lobe
Back to disease index
References |