The result is that neurons die, leading to memory loss, dementia, and eventually death.
Certain genes increase the odds of Alzheimer's, but the most critical known risk factor is simply old age.
About 4.5 million Americans have the disease. That number is expected to triple to more than 13.2 million by 2050, when 20 percent of the U.S. population will be over 65.
Alzheimer's is the seventh leading cause of death in the United States.
2. Etymology: although the origin of the concept of dementia goes as far back as the ancient Greek and Roman philosophers and physicians; it was in 1901 when Alois Alzheimer (1864-1915), a German neurologist, identified the first case of what became known as Alzheimer's disease which currently describes individuals of all ages with a characteristic common symptom pattern, disease course, and neuropathology.
Delusions and hallucinations may occur. The most common degenerative brain disorder, Alzheimer disease makes up 70% of all cases of dementia. Onset is usually in late middle life, and death typically takes place in five to ten years.
Synonyms: Alzheimer dementia, presenile dementia; dementia presenilis, primary senile dementia, primary neuronal degeneration.
Alzheimer disease ranks fourth as a cause of death in the U.S., and its annual cost to the nation is nearly $100 billion.
Onset is typically insidious, with a progressive deterioration in the ability to learn and retain information. In recalling and repeating new material, the patient makes intrusion errors (insertion of irrelevant words or ideas) and resorts to confabulation (fabrication of stories in response to questions about situations or events that are not recalled).
Orientation and judgment decline; 50% of patients experience depression, 20% delusions. Agitation occurs in 70%. Numerous drugs, including many not considered psychoactive, can aggravate the symptoms of Alzheimer disease; clinical depression can mask dementia, and vice versa.
Neurologic findings may be essentially normal, but myoclonus (condition of abnormal contraction of muscles or portions of muscles), bradykinesia (slow movements), rigidity, and seizures can occur late in the disease. Death is usually due to sepsis (blood stream infection or blood poisoning) associated with urinary or pulmonary infection.