Alzheimer's disease

Alzheimer's disease is a progressive disease that destroys memory and other important mental functions.

It's the most common cause of dementia — a group of brain disorders that results in the loss of intellectual and social skills. These changes are severe enough to interfere with day-to-day life.

In Alzheimer's disease, the brain cells themselves degenerate and die, causing a steady decline in memory and mental function.

Current Alzheimer's disease medications and management strategies may temporarily improve symptoms. This can sometimes help people with Alzheimer's disease maximize function and maintain independence.

But because there's no cure for Alzheimer's disease, it's important to seek supportive services and tap into your support network as early as possible.

SYMPTOMS
At first, increasing forgetfulness or mild confusion may be the only symptoms of Alzheimer's disease that you notice. But over time, the disease robs you of more of your memory, especially recent memories. The rate at which symptoms worsen varies from person to person.

If you have Alzheimer's, you may be the first to notice that you're having unusual difficulty remembering things and organizing your thoughts. Or you may not recognize that anything is wrong, even when changes are noticeable to your family members, close friends or co-workers.

Brain changes associated with Alzheimer's disease lead to growing trouble with:

Memory

Everyone has occasional memory lapses. It's normal to lose track of where you put your keys or forget the name of an acquaintance. But the memory loss associated with Alzheimer's disease persists and worsens, affecting your ability to function at work and at home. People with Alzheimer's may:

Repeat statements and questions over and over, not realizing that they've asked the question beforeForget conversations, appointments or events, and not remember them laterRoutinely misplace possessions, often putting them in illogical locationsEventually forget the names of family members and everyday objects

Disorientation and misinterpreting spatial relationships

People with Alzheimer's disease may lose their sense of what day it is, the season, where they are or even their current life circumstances. Alzheimer's may also disrupt your brain's ability to interpret what you see, making it difficult to understand your surroundings. Eventually, these problems may lead to getting lost in familiar places.

Speaking and writing

Those with Alzheimer's may have trouble finding the right words to identify objects, express thoughts or take part in conversations. Over time, the ability to read and write also declines.

Thinking and reasoning

Alzheimer's disease causes difficulty concentrating and thinking, especially about abstract concepts like numbers. It may be challenging to manage finances, balance checkbooks, and keep track of bills and pay them on time. These difficulties may progress to inability to recognize and deal with numbers.

Making judgments and decisions

Responding effectively to everyday problems, such as food burning on the stove or unexpected driving situations, becomes increasingly challenging.

Planning and performing familiar tasks

Once-routine activities that require sequential steps, such as planning and cooking a meal or playing a favorite game, become a struggle as the disease progresses. Eventually, people with advanced Alzheimer's may forget how to perform basic tasks such as dressing and bathing.

Changes in personality and behavior

Brain changes that occur in Alzheimer's disease can affect the way you act and how you feel. People with Alzheimer's may experience:

DepressionAnxietySocial withdrawalMood swingsDistrust in othersIrritability and aggressivenessChanges in sleeping habitsWanderingLoss of inhibitionsDelusions, such as believing something has been stolen

Many important skills are not lost until very late in the disease. These include the ability to read, dance and sing, enjoy old music, engage in crafts and hobbies, tell stories, and reminisce.

This is because information, skills and habits learned early in life are among the last abilities to be lost as the disease progresses. Capitalizing on these abilities can allow you to continue to have successes and maintain a high quality of life even when you are into the moderate phase of the disease.

CAUSES
Scientists believe that for most people, Alzheimer's disease results from a combination of genetic, lifestyle and environmental factors that affect the brain over time.

Less than 5 percent of the time, Alzheimer's is caused by specific genetic changes that virtually guarantee a person will develop the disease.

Although the causes of Alzheimer's are not yet fully understood, its effect on the brain is clear. Alzheimer's disease damages and kills brain cells. A brain affected by Alzheimer's disease has many fewer cells and many fewer connections among surviving cells than does a healthy brain.

As more and more brain cells die, Alzheimer's leads to significant brain shrinkage. When doctors examine Alzheimer's brain tissue under the microscope, they see two types of abnormalities that are considered hallmarks of the disease:

Plaques. These clumps of a protein called beta-amyloid may damage and destroy brain cells in several ways, including interfering with cell-to-cell communication. Although the ultimate cause of brain-cell death in Alzheimer's isn't known, the collection of beta-amyloid on the outside of brain cells is a prime suspect.

Tangles. Brain cells depend on an internal support and transport system to carry nutrients and other essential materials throughout their long extensions. This system requires the normal structure and functioning of a protein called tau.

In Alzheimer's, threads of tau protein twist into abnormal tangles inside brain cells, leading to failure of the transport system. This failure is also strongly implicated in the decline and death of brain cells.

Increasing age is the greatest known risk factor for Alzheimer's. Alzheimer's is not a part of normal aging, but your risk increases greatly after you reach age 65. Nearly half of those older than age 85 have Alzheimer's.

People with rare genetic changes that virtually guarantee they'll develop Alzheimer's begin experiencing symptoms as early as their 30s.

Family history and genetics

Your risk of developing Alzheimer's appears to be somewhat higher if a first-degree relative — your parent or sibling — has the disease. Scientists have identified rare changes (mutations) in three genes that virtually guarantee a person who inherits them will develop Alzheimer's. But these mutations account for less than 5 percent of Alzheimer's disease.

Most genetic mechanisms of Alzheimer's among families remain largely unexplained. The strongest risk gene researchers have found so far is apolipoprotein e4 (APOE e4). Other risk genes have been identified but not conclusively confirmed.

Sex

Women may be more likely than are men to develop Alzheimer's disease, in part because they live longer.

Mild cognitive impairment

People with mild cognitive impairment (MCI) have memory problems or other symptoms of cognitive decline that are worse than might be expected for their age, but not severe enough to be diagnosed as dementia.

Those with MCI have an increased risk — but not a certainty — of later developing dementia. Taking action to develop a healthy lifestyle and strategies to compensate for memory loss at this stage may help delay or prevent the progression to dementia.

Past head trauma

People who've had a severe head trauma or repeated head trauma appear to have a greater risk of Alzheimer's disease.

Lifestyle and heart health

There's no lifestyle factor that's been conclusively shown to reduce your risk of Alzheimer's disease.

However, some evidence suggests that the same factors that put you at risk of heart disease also may increase the chance that you'll develop Alzheimer's. Examples include:

Lack of exerciseSmokingHigh blood pressureHigh blood cholesterolElevated homocysteine levelsPoorly controlled diabetesA diet lacking in fruits and vegetables

These risk factors are also linked to vascular dementia, a type of dementia caused by damaged blood vessels in the brain. Working with your health care team on a plan to control these factors will help protect your heart — and may also help reduce your risk of Alzheimer's disease and vascular dementia.

Lifelong learning and social engagement

Studies have found an association between lifelong involvement in mentally and socially stimulating activities and reduced risk of Alzheimer's disease.

Factors that may reduce your risk of Alzheimer's include:

Higher levels of formal educationA stimulating jobMentally challenging leisure activities, such as reading, playing games or playing a musical instrumentFrequent social interactions

Scientists can't yet explain this link. One theory is that using your brain develops more cell-to-cell connections, which protects your brain against the impact of Alzheimer-related changes.

COMPLICATIONS
Memory and language loss, impaired judgment, and other cognitive changes caused by Alzheimer's can complicate treatment for other health conditions. A person with Alzheimer's disease may not be able to:

Communicate that he or she is experiencing pain — for example, from a dental problemReport symptoms of another illnessFollow a prescribed treatment planNotice or describe medication side effects

As Alzheimer's disease progresses to its last stages, brain changes begin to affect physical functions, such as swallowing, balance, and bowel and bladder control. These effects can increase vulnerability to additional health problems such as:

Pneumonia and other infections. Difficulty swallowing may cause people with Alzheimer's to inhale (aspirate) food or liquid into their airways and lungs, which can lead to pneumonia.

Inability to control emptying of the bladder (urinary incontinence) may require placement of a tube to drain and collect urine (urinary catheter). Having a catheter increases your risk of urinary tract infections, which can lead to more-serious, life-threatening infections.

Injuries from falls. People with Alzheimer's become increasingly vulnerable to falling. Falls can lead to fractures. In addition, falls are a common cause of serious head injuries.

DIAGNOSIS
There's no specific test today that confirms you have Alzheimer's disease. Your doctor will make a judgment about whether Alzheimer's is the most likely cause of your symptoms based on the information you provide and results of various tests that can help clarify the diagnosis.

Doctors can nearly always determine whether you have dementia, and they can often identify whether your dementia is due to Alzheimer's disease. Alzheimer's disease can be diagnosed with complete accuracy only after death, when microscopic examination of the brain reveals the characteristic plaques and tangles.

To help distinguish Alzheimer's disease from other causes of memory loss, doctors now typically rely on the following types of tests.

Physical and neurological exam

Your doctor will perform a physical exam, and is likely to check your overall neurological health by testing your:

ReflexesMuscle tone and strength Ability to get up from a chair and walk across the roomSense of sight and hearingCoordinationBalance

Lab tests

Blood tests may help your doctor rule out other potential causes of memory loss and confusion, such as thyroid disorders or vitamin deficiencies.

Mental status testing

Your doctor may conduct a brief mental status test to assess your memory and other thinking skills. Short forms of mental status testing can be done in about 10 minutes.

Neuropsychological testing

Your doctor may recommend a more extensive assessment of your thinking and memory. Longer forms of neuropsychological testing, which can take several hours to complete, may provide additional details about your mental function compared with others' of a similar age and education level.

This type of testing may be especially helpful if your doctor thinks you may have a very early stage of Alzheimer's disease or another dementia. These tests may also help identify patterns of change associated with different types of dementia and can help doctors estimate your ability to safely manage important activities, such as financial and medical decision-making.

Brain imaging

Images of the brain are now used chiefly to pinpoint visible abnormalities related to conditions other than Alzheimer's disease — such as strokes, trauma or tumors — that may cause cognitive change. New imaging applications — currently used primarily in major medical centers or in clinical trials — may enable doctors to detect specific brain changes caused by Alzheimer's.

Brain-imaging technologies include:

Magnetic resonance imaging (MRI). An MRI uses radio waves and a strong magnetic field to produce detailed images of your brain. You lie on a narrow table that slides into a tube-shaped MRI machine, which makes loud banging noises while it produces images. MRIs are painless, but some people feel claustrophobic inside the machine and are disturbed by the noise.

MRIs are used to rule out other conditions that may account for or be adding to cognitive symptoms. In addition, they may be used to assess whether shrinkage in brain regions implicated in Alzheimer's disease has occurred.

Computerized tomography (CT). For a CT scan, you'll lie on a narrow table that slides into a small chamber. X-rays pass through your body from various angles, and a computer uses this information to create cross-sectional images (slices) of your brain. It's currently used chiefly to rule out tumors, strokes and head injuries.

Positron emission tomography (PET). During a PET scan, you'll be injected in a vein with a low-level radioactive tracer. You'll lie on a table while an overhead scanner tracks the tracer's flow through your brain.

The tracer may be a special form of glucose (sugar) that shows overall activity in various brain regions. This can show which parts of your brain aren't functioning well. New PET techniques may be able to detect your brain level of plaques and tangles, the two hallmark abnormalities linked to Alzheimer's.

Future diagnostic tests

Researchers are working with doctors to develop new diagnostic tools to help definitively diagnose Alzheimer's. Another important goal is to detect the disease before it causes the symptoms targeted by current diagnostic techniques — at the stage when Alzheimer's may be most treatable as new drugs are discovered. This stage is called preclinical Alzheimer's disease.

New tools under investigation include:

Additional approaches to brain imagingMore-sensitive tests of mental abilitiesMeasurement of key proteins or protein patterns in blood or spinal fluid (biomarkers)

TREATMENT
Current Alzheimer's medications can help for a time with memory symptoms and other cognitive changes. Two types of drugs are currently used to treat cognitive symptoms:

Cholinesterase inhibitors. These drugs work by boosting levels of a cell-to-cell communication chemical depleted in the brain by Alzheimer's disease. Most people can expect to keep their current symptoms at bay for a time.

Less than half of those taking these drugs can expect to have any improvement. Commonly prescribed cholinesterase inhibitors include donepezil (Aricept), galantamine (Razadyne) and rivastigmine (Exelon). The main side effects of these drugs include diarrhea, nausea and sleep disturbances.

Memantine (Namenda). This drug works in another brain cell communication network and slows the progression of symptoms with moderate to severe Alzheimer's disease. It's sometimes used in combination with a cholinesterase inhibitor.

Creating a safe and supportive environment

Adapting the living situation to the needs of a person with Alzheimer's is an important part of any treatment plan. For someone with Alzheimer's, establishing and strengthening routine habits and minimizing memory-demanding tasks can make life much easier.

You can take these steps to support a person's sense of well-being and continued ability to function:

Always keep keys, wallets, mobile phones and other valuables in the same place at home, so they don't become lost.See if your doctor can simplify your medication regimen to once-daily dosing, and arrange for your finances to be on automatic payment and automatic deposit.Develop the habit of carrying a mobile phone with location capability so that you can call in case you are lost or confused and people can track your location via the phone. Also, program important phone numbers into your phone, so you don't have to try to recall them.Make sure regular appointments are on the same day at the same time as much as possible.Use a calendar or white board in the home to track daily schedules. Build the habit of checking off completed items so that you can be sure they were completed.Remove excess furniture, clutter and throw rugs.Install sturdy handrails on stairways and in bathrooms.Ensure that shoes and slippers are comfortable and provide good traction.Reduce the number of mirrors. People with Alzheimer's may find images in mirrors confusing or frightening.

Exercise

Regular exercise is an important part of everybody's wellness plan — and those with Alzheimer's are no exception. Activities such as a daily 30-minute walk can help improve mood and maintain the health of your joints, muscles and heart.

Exercise can also promote restful sleep and prevent constipation. Make sure that the person with Alzheimer's carries identification if she or he walks unaccompanied.

People with Alzheimer's who develop trouble walking may still be able to use a stationary bike or participate in chair exercises. You may be able to find exercise programs geared to older adults on TV or on DVDs.

Nutrition

People with Alzheimer's may forget to eat, lose interest in preparing meals or not eat a healthy combination of foods. They may also forget to drink enough, leading to dehydration and constipation.

Offer:

High-calorie, healthy shakes and smoothies. You can supplement milkshakes with protein powders (available at grocery stores, drugstores and discount retailers) or use your blender to make smoothies featuring your favorite ingredients.Water, juice and other healthy beverages. Try to ensure that a person with Alzheimer's drinks at least several full glasses of liquids every day. Avoid beverages with caffeine, which can increase restlessness, interfere with sleep and trigger frequent need to urinate.

Certain nutritional supplements are marketed as \"medical foods\" specifically to treat Alzheimer's disease. The Food and Drug Administration (FDA) does not approve products marketed as medical foods. Despite marketing claims, there's no definitive data showing that any of these supplements is beneficial or safe.