About Alzheimer's from the Alzheimer Foundation of America
Definition of Alzheimers
* Alzheimer's disease is a progressive, degenerative disorder that attacks the brain's nerve cells, or neurons, resulting in loss of memory, thinking and language skills, and behavioral changes.
* These neurons, which produce the brain chemical, or neurotransmitter, acetylcholine, break connections with other nerve cells and ultimately die. For example, short-term memory fails when Alzheimer's disease first destroys nerve cells in the hippocampus, and language skills and judgment decline when neurons die in the cerebral cortex.
* Two types of abnormal lesions clog the brains of individuals with Alzheimer's disease: Beta-amyloid plaques—sticky clumps of protein fragments and cellular material that form outside and around neurons; and neurofibrillary tangles—insoluble twisted fibers composed largely of the protein tau that build up inside nerve cells. Although these structures are hallmarks of the disease, scientists are unclear whether they cause it or a byproduct of it.
* Alzheimer's disease is the most common cause of dementia, or loss of intellectual function, among people aged 65 and older.
* Alzheimer's disease is not a normal part of aging.
* Origin of the term Alzheimer's disease dates back to 1906 when Dr. Alois Alzheimer, a German physician, presented a case history before a medical meeting of a 51-year-old woman who suffered from a rare brain disorder. A brain autopsy identified the plaques and tangles that today characterize Alzheimer's disease.
Warning Signs
Although every case of Alzheimer's disease is different, experts have identified common warning signs of the brain disease. Remember, Alzheimer's disease is not a normal part of aging, and it is important to look for signs that might indicate Alzheimer's disease versus basic forgetfulness. With Alzheimer's disease, these symptoms gradually increase and become more persistent.
If someone is exhibiting these symptoms, the person should check out his or her concerns with a healthcare professional. Awareness of these warning signs is not a substitute for a structured screening or consultation with a primary care provider.
Typical warning signs include:
* Memory loss, especially of recent events, names, placement of objects, and other new information
* Confusion about time and place
* Struggling to complete familiar actions, such as brushing teeth or getting dressed
* Trouble finding the appropriate words, completing sentences, and following directions and conversations
* Poor judgment when making decisions
* Changes in mood and personality, such as increased suspicion, rapid and persistent mood swings, withdrawal, and disinterest in usual activities
* Difficulty with complex mental assignments, such as balancing a checkbook or other tasks involving numbers
Diagnosis
* Clinicians can now diagnose Alzheimer's disease with up to 90 percent accuracy. But it can only be confirmed by an autopsy, during which pathologists look for the disease's characteristic plaques and tangles in brain tissue.
* Clinicians diagnose "probable" Alzheimer's disease by taking a complete medical history and conducting lab tests, a physical exam, brain scans and neuropsychological tests that gauge memory, attention, language skills and problem-solving abilities.
* Proper diagnosis of Alzheimer's disease is critical since there are dozens of other causes of dementia that could exhibit the same symptoms. Some of these dementias, such as those caused by vitamin deficiency, thyroid problems and depression, are reversible; of those that are irreversible, Alzheimer's disease is the most common.
* The sooner an accurate diagnosis of "probable" Alzheimer's disease is made, the easier it is to manage symptoms and plan for the future.
Symptoms
* Symptoms are divided into two categories: cognitive, or intellectual, and psychiatric.
* Differentiating them is important so that behavioral problems that are caused by loss of cognitive functioning are not treated with anti-psychotic or anti-anxiety medications.
* Cognitive, or intellectual, symptoms are amnesia, aphasia, apraxia and agnosia (the 4 As of Alzheimer's).
* Amnesia is defined as loss of memory, or the inability to remember facts or events. We have two types of memories: the short-term (recent, new) and long-term (remote, old) memories. Short-term memory is programmed in a part of the brain called the temporal lobe, while long-term memory is stored throughout extensive nerve cell networks in the temporal and parietal lobes. In Alzheimer's disease, short-term memory storage is damaged first.
* Aphasia is the inability to communicate effectively. The loss of ability to speak and write is called expressive aphasia. An individual may forget words he has learned, and will have increasing difficulty with communication. With receptive aphasia, an individual may be unable to understand spoken or written words or may read and not understand a word of what is read. Sometimes an individual pretends to understand and even nods in agreement; this is to cover-up aphasia. Although individuals may not understand words and grammar, they may still understand non-verbal behavior, i.e., smiling.
* Apraxia is the inability to do pre-programmed motor tasks, or to perform activities of daily living such as brushing teeth and dressing. An individual may forget all motor skills learned during development. Sophisticated motor skills that require extensive learning, such as job-related skills, are the first functions that become impaired. More instinctive functions like chewing, swallowing and walking are lost in the last stages of the disease.
* Agnosia is an individual's inability to correctly interpret signals from their five senses. Individuals with Alzheimer's disease may not recognize familiar people and objects. A common yet often unrecognized agnosia is the inability to appropriately perceive visceral, or internal, information such as a full bladder or chest pain.
* Major psychiatric symptoms include personality changes, depression, hallucinations and delusions.
* Personality changes can become evident in the early stages of Alzheimer's disease. Signs include irritability, apathy, withdrawal and isolation.
* Individuals may show symptoms of depression at any stage of the disease. Depression is treatable, even in the latter stages of Alzheimer's disease.
* Psychotic symptoms include hallucinations and delusions, which usually occur in the middle stage. Hallucinations typically are auditory and/or visual, and sensory impairments, such as hearing loss or poor eyesight, tend to increase hallucinations in the elderly.
* Hallucinations and delusions can be very upsetting to the person with the disease. Common reactions are feelings of fear, anxiety and paranoia, as well as agitation, aggression and verbal outbursts.
* Individuals with psychiatric symptoms tend to exhibit more behavioral problems than those without these symptoms. It is important to recognize these symptoms so that appropriate medications can be prescribed and safety precautions can be taken.
* Psychotic symptoms can often be reduced through the carefully supervised use of medications. Talk to your primary care doctor, neurologist or geriatric psychiatrist about these symptoms because they are treatable.
Life Expectancy
* Alzheimer's disease stretches from two to twenty years, and individuals live on average for eight to ten years from diagnosis.
* Individuals with Alzheimer's disease are likely to develop co-existing illnesses and most commonly die from pneumonia.
* Alzheimer's disease is the sixth leading cause of death in the U.S.
Treatment
* Currently, there is no cure for Alzheimer's disease.
* Researchers are continually testing the effectiveness of various drug therapies that will control symptoms; slow, reduce and/or reverse mental and behavioral symptoms; and prevent or halt the disease.
* The U.S. Food and Drug Administration (FDA) has approved medications known as cholinesterase inhibitors: donepezil hydrochloride (Aricept), approved for all stages of Alzheimer's disease; rivastigmine (Exelon), approved in pill and patch form for mild to moderate Alzheimer's disease; and galantamine hydrobromide (Razadyne), approved for mild to moderate Alzheimer's disease. These drugs inhibit the enzyme that breaks down the brain chemical acetylcholine, and thereby may help slow the worsening of symptoms.
* The FDA has approved memantine HCI (Namenda) for the treatment of moderate to severe Alzheimer's disease, which may help slow the worsening of symptoms.
* The National Institute on Aging, in concert with the FDA, tracks private- and government-sponsored clinical trials; contact the Alzheimer's Disease Education and Referral Center (www.alzheimers.org/trials or 800-438-4380).
Research
>> The causes of Alzheimer's disease are still unknown.
>> Current research indicates that Alzheimer's disease may be triggered by a multitude of factors, including age, genetic makeup, oxidative damage to neurons from the overproduction of toxic free radicals, serious head injuries, brain inflammation, and environmental factors.
>> Age is the most important known risk factor for Alzheimer's disease.
>> There are two types of the disease: sporadic Alzheimer's disease and familial Alzheimer's disease (FAD). Unlike sporadic Alzheimer's disease, FAD follows an obvious inheritance pattern. Less than ten percent of Alzheimer's disease cases are FAD. This rare form of Alzheimer's disease usually occurs between the ages of 30 and 60.
>> On the genetic front, scientists have zeroed in on three mutations on chromosomes 1, 14 and 21 that cause early-onset Alzheimer's disease, which generally affects those aged 30 to 60.
>> Other genes boost susceptibility, but do not signal that a person will definitely develop the disease. Multiple research studies indicate that inheritance of a specific one of the three forms, or alleles, of the apolipoprotein E (apoE) gene on chromosome 19 heightens the risk of late-onset Alzheimer's disease. Those who carry one copy of the allele e4 face a higher risk of developing Alzheimer's disease, and those with two copies of e4 confront the greatest risk. Another relatively rare apoE allele, e2, appears linked to a lower risk of the disease.
>> Several other studies suggest that a gene or genes on chromosome 10 may also boost an individual's risk of developing late-onset Alzheimer's disease.
