Thursday, October 15, 2009

Alzheimer's Disease


What is Alzheimer's Disease?

Dementia is a brain disorder that seriously affects a person's ability to carry out daily activities. The most common form of dementia among older people is Alzheimer's disease (also known simply as Alzheimer's). This condition initially affects parts of the brain that control thinking, memory, and language.


Alzheimer's is named after Dr. Alois Alzheimer, a German doctor. In 1906, Dr. Alzheimer noticed changes in the brain of a woman who had died of an unusual mental illness. Within the brain tissue, he found abnormal clumps (now called amyloidplaques) and tangled bundles of fibers (now called neurofibrillary tangles). Today, these plaques and tangles in the brain are considered signs of Alzheimer's disease.
  • Amyloid plaques, which are made up of fragments of a protein called beta-amyloid peptide mixed with a collection of additional proteins, remnants of neurons, and bits and pieces of other nerve cells.
  • Neurofibrillary tangles (NFTs), found inside neurons, are abnormal collections of a protein called tau. Normal tau is required for healthy neurons. However, in AD, tau clumps together. As a result, neurons fail to function normally and eventually die.
  • Loss of connections between neurons responsible for memory and learning. Neurons can't survive when they lose their connections to other neurons. As neurons die throughout the brain, the affected regions begin to atrophy, or shrink. By the final stage of AD, damage is widespread and brain tissue has shrunk significantly.

Stages of Alzheimer's Disease

Alzheimer's Disease develops slowly and causes changes in the brain long before there are obvious changes in a person's memory, thinking, use of words, or behavior. There are three Alzheimer's stages: mild, moderate and severe . Each of the three stages is characterized by different symptoms.


Mild Alzheimer's Disease
A person with mild Alzheimer's disease may:
  • Lose zest for life.
  • Lose recent memory without a change in appearance or casual conversation.
  • Lose the ability to make judgments concerning money.
  • Have difficulty with new learning and making new memories.
  • Have trouble finding words. He or she may substitute or make up words that sound like or mean something like the forgotten word.
  • May stop talking to avoid making mistakes.
  • Have a shorter attention span and less motivation to stay with an activity.
  • Easily lose his or her way going to familiar places.
  • Resist change or new things.
  • Have trouble organizing and thinking logically.
  • Ask repetitive questions.
  • Withdraw, lose interest, or become irritable. He or she may not be as sensitive to others' feelings or become uncharacteristically angry when frustrated or tired.
  • Avoid making decisions. For example, when asked what he or she wants to eat, says, "I'll have what she is having."
  • Take longer to do routine chores, becoming upset if rushed or if something unexpected happens.
  • Forget to pay, pay too much, or forget how to pay. For instance, he or she may hand the checkout person a wallet instead of the correct amount of money.
  • Forget to eat, eat only one kind of food, or eat constantly.
  • Lose or misplace things by hiding them in odd places or forget where things go. For example, the person may put clothes in the dishwasher.
  • Hoard things of no value.

Moderate Alzheimer's Disease

Common symptoms in this stage of Alzheimer's disease can include:
  • Changes in behavior, concern for appearance, hygiene, and sleep (which become more noticeable).
  • Inability to identify close relatives (such as thinking a son is a brother or that a wife is a stranger).
  • Poor judgment (This creates safety issues when the person is left alone -- he or she may wander and risk exposure, poisoning, falls, self-neglect, or exploitation.).
  • Difficulty recognizing familiar people and objects. The person may take things belonging to others.
  • Repetition of stories, favorite words, statements, or motions (such as tearing tissues).
  • Engaging in restless, repetitive movements in late afternoon or evening (such as pacing, trying doorknobs, or fingering draperies).
  • Inability to organize thoughts or follow logical explanations.
  • Difficulty completing tasks.
  • Telling stories to fill in gaps in memory.
  • Inability to formulate the correct response to a written request.
  • Inappropriate behavior (such as kicking, hitting, biting, screaming, cursing, or grabbing).
  • Becoming sloppy or forgetting manners.
  • Sensing things that are not there.
  • Making accusations (such as accusing a spouse of an affair or family members of stealing).
  • Frequent napping (or waking up at night and believing it is morning).
  • Difficulty positioning the body to use the toilet or sit in a chair.
  • Thinking that a mirror image is following him or television story is happening to her.
  • assistance to find the toilet, use the shower, remember to drink, and dress for the weather or occasion.
  • Inappropriate sexual behavior, such as mistaking another individual for a spouse. A person with Alzheimer's disease may forget what is considered private behavior and may disrobe or masturbate in public.


Severe Alzheimer's Disease
Common symptoms in this Alzheimer's stage can include:
  • Inability to recognize self or close family
  • Speaking gibberish or acting mute
  • Refusing to eat; choking or forgetting to swallow
  • Repetitively crying out; patting or touching everything
  • Loss of bowel and bladder control
  • Weight loss
  • Skin that becomes thin and tears easily
  • Becoming uncomfortable or crying out when transferred or touched
  • Forgetting how to walk (or being too unsteady or weak to stand alone)
  • Seizures, frequent infections, or falls
  • Groaning, screaming, or loud mumbling
  • Sleeping more
  • Requiring total assistance for all activities of daily living.

Diagnosing Alzheimer's Disease

Diagnosing Alzheimer's disease in the early stages will offer the best opportunity to treat related symptoms. An early diagnosis will also help patients and their families plan for the future while the patient is still able to participate in the decision-making process. Tests that doctors use when diagnosing Alzheimer's include memory tests, medical tests, and brain scans.


Causes of Alzheimer's Disease

While there are no known causes of Alzheimer's disease, there are factors that can increase a person's risk for developing this condition. Risk factors that may contribute to the causes of Alzheimer's disease include age, family history, and certain genes. Scientists are currently studying other possible risk factors and causes of Alzheimer's disease, such as: high blood pressure, high cholesterol, and low levels of the vitamin folate.

Alzheimer's disease risk factors include:

  • Age
  • Family history
  • Certain genes.


Age
Age is the most important known risk factor for Alzheimer's disease. The number of people with the disease doubles every 5 years beyond age 65.

Family History
Family history is another risk factor. Scientists believe that genetics may play a role in many cases of Alzheimer's disease. For example, familial Alzheimer's disease (a rare form of Alzheimer's disease that usually occurs between the ages of 30 and 60) is inherited.

Certain Genes
The more common form of Alzheimer's disease is known as late-onset Alzheimer's. It occurs later in life, and no obvious inheritance pattern is seen in most families. However, several risk factor genes may interact with each other and with non-genetic factors to cause the disease.

The only risk factor gene identified so far for late-onset Alzheimer's disease is a gene that makes one form of a protein called apolipoprotein E (ApoE). Everyone has ApoE, which helps carry cholesterol in the blood. Only about 15% of people have the form that increases the risk of Alzheimer's disease. It is likely that other genes may also increase the risk of Alzheimer's disease or protect against Alzheimer's disease, but they remain to be discovered.


Is there any Treatment?

Alzheimer's Disease is a slow disease that starts with mild memory problems and ends with severe brain damage. The course the disease takes and how fast changes occur vary from person to person. On average, patients with Alzheimer's disease live from 8 to 10 years after they are diagnosed, although some people may live with the condition for as long as 20 years.
Currently, there is no Alzheimer's treatment that can stop Alzheimer's disease. However, there are medications available to help with related symptoms.

Alzheimer's Treatment for Mild to Moderate Disease

For some people in the early and middle stages of Alzheimer's disease, there are medications that may prevent some Alzheimer's symptoms from becoming worse for a period of time. These medications include:
Scientists do not yet fully understand how cholinesterase inhibitors work to treat Alzheimer's disease, but current research indicates that they prevent the breakdown of acetylcholine -- a brain chemical believed to be important for memory and thinking. As Alzheimer's disease progresses, the brain produces less and less acetylcholine. Therefore, cholinesterase inhibitors may eventually lose their effect.
Currently, there are no published studies that directly compare these drugs. Therefore, because all four medications work in a similar way, it is not expected that switching from one of these drugs to another will produce significantly different results. However, a person with Alzheimer's disease may respond better to one drug than another. It is important to note that Cognex® (tacrine) is no longer actively marketed by the manufacturer


Treating Moderate to Severe Disease

Donepezil is also approved to treat severe Alzheimer's disease. Another drug,memantine (Namenda®), has also been approved to treat moderate to severe Alzheimer's disease, although it also is limited in its effects. Combining memantine with other Alzheimer's medications may be more effective than any single therapy. One controlled clinical trial found that patients receiving donepezil plus memantine had better cognition and other functions than patients receiving donepezil alone.


Dose and Side Effects of Alzheimer's Disease Medication


For Alzheimer's disease medication, doctors usually start patients at low drug doses and gradually increase the dosage based on how well a patient tolerates the drug. There is some evidence that certain patients may benefit from higher doses of the cholinesterase inhibitor medications. However, side effects are more likely to occur if the dose is higher. The recommended effective dosage of Namenda is 20 mg/day after the patient has successfully tolerated lower doses.
Patients may be drug sensitive in other ways, and they should be monitored when a drug is started. Patients or their caregivers should:
  • Report any unusual symptoms to the prescribing doctor right away
  • Let the doctor know before adding or changing any medications
  • Follow the doctor's instructions when taking any medication, including vitamins and herbal supplements.

Prevent Alzheimer's


Until there is a cure or the causes of the disease are identified, actions that may help prevent Alzheimer's include: lowering cholesterol, lowering high blood pressure levels, controlling diabetes, exercising regularly, and engaging in intellectually stimulating activities. Although this does not guarantee Alzheimer's will not occur, it may help delay the disease's development. Before trying anything that promises to prevent Alzheimer's, check it out with your doctor first.


Current Focus of Research on Alzheimer's

Alzheimer's research scientists are studying various aspects of the disease. Recent research studies, including those currently under way, are focused on the following areas:
  • Genetics
  • Mild cognitive impairment
  • Neuroimaging
  • Inflammation
  • Medications
  • Antioxidants
  • Ginkgo biloba
  • Estrogen.
Alzheimer's research scientists are currently testing a number of drugs to see if they:
Some ideas that seem promising turn out to have little or no benefit when they are carefully studied in a clinical trial. Researchers undertake these trials to learn whether treatments that appear promising in observational and animal studies are actually safe and effective in people.

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