According to the National Institutes of Health, approximately 3.5 million Americans suffer from Alzheimer's disease, the most frequent cause of the cognitive disorder dementia among the elderly. A progressive, irreversible and eventually fatal brain condition, Alzheimer's gradually impairs mental functions, such as remembering and thinking, ultimately creating an inability to perform basic daily tasks independently.
History
The name Alzheimer's disease comes from Alois Alzheimer, the German doctor who first defined the medical condition after encountering a 51-year-old patient in 1901. The woman, called Frau Auguste D. in Alzheimer's subsequent case study, suffered from progressively worse memory problems, difficulty producing and understanding language and untrue suspicions of her husband's faithfulness.
After she died from the disease, in 1906, Alzheimer conducted an autopsy that showed vessels filled with substances (later named amyloid plaques), damaged brain cells, tangled groups of fibers (later named neurofibrillary tangles), and a shrunken cortex, the part of the brain responsible for cognitive functions like memory and speech. The condition was officially named Alzheimer's disease in 1910 on the suggestion of German psychiatrist Emil Kraepelin.
Symptoms
Alzheimer's disease typically begins with minimal signs of occasional confusion and memory lapses. Eventually, the symptoms increase in frequency and degree, until the person develops dementia, a term used to classify cognitive impairments that are great enough to interfere with daily life. Common Alzheimer's symptoms include memory loss, difficulty speaking and understanding both written and spoken language, disorientation, personality changes and poor judgment.
Causes
Although Alzheimer's disease is more prevalent among people over age 85--almost half of Americans in that group have the disease--aging is not a cause of the condition but rather a risk factor. The exact elements that cause the disease to emerge are currently unknown; however, scientists think a mixture of environmental, genetic and lifestyle factors trigger Alzheimer's.
After the onset of Alzheimer's disease, two types of damage affect the 100 billion neurons (nerve cells) in the brain, slowly killing them and interfering with the neural networks that perform distinct functions. The first is related to plaques, where deposits of the protein beta-amyloid, which aren't usually harmful, accumulate between neurons and begin to disrupt communication between cells in the brain. The second involves tangles, where fibers made of the protein tau become entangled inside of dying brain cells.
Risk Factors
Age, genetics, sex and lifestyle are four major risk factors for developing Alzheimer's disease. The disease is most common in people older than 85, and it affects approximately 5 percent of adults between age 65 and 74. People who have an immediate relative, such as a parent or sibling, with Alzheimer's are more likely to develop the disease, as are women, simply because they tend to live longer a time. Those who have conditions like high cholesterol, high blood pressure and inadequately treated diabetes are also at higher risk, as well as individuals with less education or a milder form of cognitive problems.
Treatment
Despite the lack of a cure for Alzheimer's and the disease's severity, it's possible to treat some of the symptoms to improve a person's quality of life. Two prescription medications that can decrease the rate at which cognitive functions decline are cholinesterase inhibitors, which increase the amount of neurotransmitters found in the brain, and memantine (Namenda), which helps protect cells in the brain from the damaging chemical glutamate.
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