Dementia refers to a category of disorders that involve memory loss while Alzheimer's disease (AD) is a specific disease. Alzheimer's disease causes dementia, however, several other diseases or conditions, such as stroke, Parkinson's disease, head injury, and vitamin deficiency can also cause dementia.
The term "dementia" is used loosely to describe severe memory loss and impairment in other thinking (or "cognitive") abilities that interfere with the individual's daily life and social interactions. Many different conditions and diseases cause dementia.
Alzheimer's is the most common form of dementia. It is a progressive, degenerative disease that causes a slow decline in the functioning of nerve cells in the brain. Individuals with AD experience progressive and irreversible loss of thinking abilities, including language and memory. Changes are also witnessed in mood, personality, sleep-wake cycles, and behavior. In AD, nerve cells involved in learning and short-term memory are affected early which is the reason memory loss is one of the first symptoms of Alzheimer's disease.
Everyone experiences memory lapses and forgetfulness from time to time and some decline in memory ability is a normal part of aging. For example, as an individual approaches middle age, his or her ability to recall newly learned information, such as recalling people’s names or specific words, may begin to slip. These memory problems do not get worse over short periods of time and do not interfere much with the ability to do daily activities. People may compensate for these normal memory changes by repeatedly going over things to be remembered, linking them in their mind with something already well known, or keeping lists of things to do. In contrast, the memory loss in Alzheimer's disease is much greater than expected for age. The memory lapses are more frequent and severe and interfere with the ability to manage daily activities.
An individual with mild cognitive impairment, or MCI, is able to take care of themselves and go about their normal daily activities, but they have subtle problems with memory and thinking. Some signs of MCI are losing things often, forgetting appointments, and having trouble finding the right words to say. MCI can be an early sign of Alzheimer’s disease—but not everyone with MCI will develop Alzheimer’s.
Beta-amyloid is a sticky protein that gradually builds up, forming plaques within the brain of those with Alzheimer’s disease. The plaques accumulate between nerve cells in the brain, blocking their communication.
Tau is a protein that, under normal conditions, allows vital cell transport to occur within the brain. In Alzheimer’s Disease, tau collapses into twisted strands which stops the cell from obtaining essential supplies and nutrients. Cells with these tau tangles eventually die.
Plaques are abnormal clusters of beta-amyloid protein. Tangles are twisted strands of tau protein. Plaques and tangles accumulate in the brain of those with Alzheimer’s disease. Specific types of recently developed PET scans are able to detect this accumulation. Previously, all plaque and tangle quantification was done through autopsy.
Typically, the first signs include:
Testing brain tissue for plaques and tangles is the only definitive way to diagnose Alzheimer’s disease. This is done during a brain autopsy after someone dies. While a person is still living, doctors are only able to make a diagnosis of “possible” or “probable” Alzheimer’s disease and this requires a full physical and neurological examination to rule out other causes of dementia. Screenings include blood tests to measure thyroid function and vitamin B12 levels, an MRI or CT scan of the brain to exclude other causes of dementia such as strokes, tumors, or hydrocephalus (excessive fluid build-up in the brain), and cognitive testing for memory, language, and other cognitive difficulties.
People with Alzheimer's disease will need support and assistance from others as they experience changes brought on by the disease. While telling friends and family may cause some emotional stress, it is important to tell people early on so that an effective and caring support network of family and friends can be established.
The average worldwide lifetime risk of developing any type of Alzheimer’s disease is about 5 percent by age 65, 10 to 15 percent by age 75, and 20 to 40 percent by age 85. Individuals who have a parent with Alzheimer’s disease have about twice the average risk of getting the disease. That is, among 65-year-olds with an affected parent, about 10 percent will develop Alzheimer’s disease.
Having a brother or sister with Alzheimer’s disease also doubles the risk. The likelihood of developing the disease continues to increase as the number of affected relatives increases, and having more than one affected sibling appears to cause the greatest increase in risk.
This increased risk occurs because children and parents may share certain genes, the basic units of heredity that provide a blueprint for many biological and behavioral characteristics. The influence of a gene may be large or small. Tests are available that can determine whether a person carries Alzheimer’s disease genes. It is important to understand, however, that even people with Alzheimer’s disease genes may not develop the disease.
In addition, an Alzheimer's disease diagnosis approaches 90 percent accuracy without genetic testing. Therefore, genetic testing is usually not essential but is recommended in those patients with early onset of symptoms (early onset AD is associated with a greater likelihood of a genetic link) and positive family history.
Most experts regard genetic testing as an acceptable part of clinical trials as long as participants give informed consent and understand the procedure’s purpose and limitations thoroughly. Most experts recommend that the complex analysis involved in characterizing such one-of-a-kind gene mutations be carried out at a major academic center and that individuals receive genetic counseling as part of the testing process. Genetic counselors help people explore emotional and legal implications as well as scientific and technical issues before testing proceeds; after testing is completed, they explain and interpret results and help people accept the outcome.
There is no medical treatment currently available to cure or stop the progression of Alzheimer's disease. However, the Food & Drug Administration (FDA) has approved several drugs that may temporarily slow cognitive changes.
The first class is acetylcholinesterase inhibitors, which are indicated for mild to severe Alzheimer’s disease. These are donepezil (Aricept®), rivastigmine (Exelon®), galantamine (Reminyl®), and tacrine (Cognex®).
The second class is NMDA antagonists, which is indicated for moderate to severe Alzheimer’s disease. There is only one drug approved in this class: memantine (Namenda®).
Many other promising drugs are being developed and tested - some of which may be available soon. (See our blog and subscribe to our e-newsletter for the latest information on new Alzheimer's treatments.) Medication and non-drug therapies are also available to help with behavior changes associated with Alzheimer's disease, such as depression, sleeplessness, and agitation.
Generally, donepezil (Aricept®), rivastigmine (Exelon®), and galantamine (Reminyl®) are well tolerated. Symptoms such as nausea, vomiting, loss of appetite, and loose stools might occur but are usually transient. It is recommended to take Reminyl® and Exelon®with a full meal. Because of side effects associated with tacrine, including possible liver damage, it is very rarely prescribed. There is no evidence or reason to believe that combining the drugs would be any more beneficial than taking either one alone, and it is likely that combining the drugs would result in greater side effects.
Research into the production of free radicals in the brain in Alzheimer's disease have suggested that antioxidants, such as vitamin E, vitamin C, and Ginko Bilbao may be useful in treating or slowing the progression of the disease. However, more research needs to be done in this area before the effectiveness or lack thereof of these supplements can be verified.
Alzheimer's disease has three stages: early (mild), middle (moderate), and late (severe). A person in the early stage of Alzheimer’s may:
Importantly, the first changes present within the brain may begin 20 or more years before diagnosis.
Those in the middle stage of Alzheimer’s exhibit:
The mild to moderate stage may last between 2 and 10 years.
In the late stage, people:
Severe Alzheimer’s may last between 1 and 5 years.
Patients in the early stages of Alzheimer's disease may have awareness of their memory and other deficits. However, awareness of memory and other problems generally decreases as the disease progresses.
Whether or not a person with Alzheimer's disease can continue to drive is dependent on the progression of the disease and their remaining functional abilities. Individuals who still drive should be encouraged to limit their driving to short distances in areas that are familiar to them. Caregivers should try to gauge whether they feel that the person is driving safely. After evaluation in the Memory Clinic, our staff can advise patients and their families regarding driving safety, and refer patients for driving safety evaluations if indicated.
Approximately 25 percent of Americans with Alzheimer's disease live alone. However, as the condition progresses, patients may need more help and it is especially important for family and friends to provide supervision for tasks that the person with AD can no longer do for themselves. Family members, friends, and community services can help.
Information is available on home care services, meals, transportation, and day care from the Alzheimer's Association or a primary care physician. Arrangements can be made for direct deposit of checks such as retirement pensions and/or Social Security benefits. Home-delivered meals are available. At some point people with AD will need to live in a supervised setting either with family, an assisted living facility, or a nursing home.
Behavior problems are common in AD, especially as the disease progresses. Depression and irritability may occur early. Suspiciousness is common. Apathy is the most common behavioral symptom. Restlessness, wandering, agitation, impulsiveness, delusions, and hallucinations may occur later. These behavioral symptoms can be very distressing to caregivers and family members. It is important to have the support of family and friends. Support groups may help. Medications may help. Your family doctor may refer you to a geriatric psychiatrist who specializes in managing behavioral problems in dementia.
You can contact your local chapter of the Alzheimer's Association for information and support in areas ranging from day-to-day living to cutting-edge medical research. The Alzheimer's Association and its local chapters also have a wealth of information and resources available online. The information for the Alzheimer's Association chapter here in Rhode Island is as follows:
Alzheimer's Association Rhode Island Chapter
www.alz.org/ri
245 Waterman Street, Suite 306
Providence, RI 02906
(800) 244-1428
(401) 421-0008
Clinical research includes studies (observing and gathering data from large groups of people) and trials (testing a medicine, therapy, or intervention in a group of people). Clinical trials are important as they allow researchers and doctors to determine if a medication or treatment is successful in slowing or preventing the disease progression. Our clinic has many opportunities for clinical research, click here to see our current trials.
No, there are strict criteria that must be met to enroll in a research trial. Our clinic doctors will determine which studies they believe you may be a good candidate for and, after signing consent, you will enter into a screening period. If you meet all criteria during the screening period, you will be enrolled in the trial. If you do not meet the necessary criteria for a study, there may be others that you will qualify for. You can only be enrolled in one clinical trial at a time.
If you would like to be automatically considered for participation in current and future Alzheimer's prevention, diagnosis and/or treatment research studies and clinical trials, please join the Butler Hospital Alzheimer's Prevention Registry online here >
All the procedures done for a research trial are done independent of your insurance or primary care doctor. The only people that will know you are in a trial are the people at the clinic who are involved in the trial and the people that you decide to tell. We work hard to make sure your information is kept confidential.
Absolutely. Before beginning any research trial you will be told of each and every step that the study will entail. All of your questions will be answered and should you feel comfortable continuing in the trial, you will sign a consent form. At any point, you are free to withdraw your consent and stop participating in the study.
Cognitive testing refers to a variety of assessments designed to measure a persons memory and thinking abilities. In Alzheimer’s research, cognitive testing often entails surveys, questionnaires, interviews, and sessions with a trained cognitive rater or doctor.
A placebo is an inactive substance designed to look like a medication. Drug trials are often ‘placebo-controlled’ meaning that some of the participants in the trial are not receiving the drug being tested, but are instead receiving a substance made only to look like the medication. Often a placebo is called a sugar pill because it does not contain any active medicines. Placebo groups serve as control groups in research. Results are compared between the placebo group and the active medication group to determine if the medicine is having an effect.
Positron emission tomography (PET) uses small amounts of radioactive material, called radiotracers, and a specialized camera and computer to “see” your organs and tissues. In Alzheimer’s research, PET scans are used to detect beta-amyloid and tau accumulation, as well as healthy and diseased tissue through use of a variety of radiotracers. The PET scan procedure begins with the technician placing an IV in your hand or arm and injecting the radiotracer. A period of time will pass as your brain absorbs the radiotracer. After the radiotracer is absorbed, you will enter the PET scanner, a large round machine similar to an MRI machine. The PET scanner will use a specialized camera to detect the radiotracer within your brain. You will not feel anything as this process occurs.
An MRI is a test that uses a large magnetic field and radio wave energy to recreate images of structures within the body. In Alzheimer’s research, MRIs are often used to image the brain as a whole, as well as specific structures within the brain. MRI images can tell doctors if brain tissue volume is shrinking, whether large or small strokes have occurred, and whether specific brain areas are displaying abnormalities.