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SENILE DEMENTIA CAUSES |
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Senile Dementia is usually caused by degeneration in the cerebral cortex, the part of the brain responsible for thoughts, memories, actions and personality. Death of brain cells in this region leads to the cognitive impairment which characterizes senile dementia. The most common cause of senile dementia is AD, accounting for half to three quarters of all cases. The brain of a person with AD becomes clogged with two abnormal structures, called neurofibrillary tangles and senile plaques. Neurofibrillary tangles are twisted masses of protein fibers inside nerve cells, or neurons. Senile plaques are composed of parts of neurons surrounding a group of proteins called beta-amyloid deposits. Why these structures develop is unknown. Current research indicates possible roles for inflammation, blood flow restriction, and toxic molecular fragments known as free radicals. Several genes have been associated with higher incidences of AD, although the exact role of these genes is still unknown. Vascular senile dementia is estimated to cause from 5-30% of all senile dementias. It occurs from decrease in blood flow to the brain, most commonly due to a series of small strokes (multi-infarct senile dementia). Other cerebrovascular causes include: vasculitis from syphilis, Lyme disease, or systemic lupus erythematosus; subdural hematoma; and subarachnoid hemorrhage. Because of the usually sudden nature of its cause, the symptoms of vascular senile dementia tend to begin more abruptly than those of Alzheimer's senile dementia. Symptoms may progress stepwise with the occurrence of new strokes. Unlike AD, the incidence of vascular senile dementia is lower after age 75. Other conditions which may cause senile dementia include:
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| SENILE DEMENTIA RELATED ITEMS | ||
