Frequently Asked Questions
Everyone’s talking about a new study that says Alzheimer’s disease might be responsible for 500,000 deaths each year—as opposed to 84,000 yearly deaths as reported by CDC. Why are these two numbers so far apart? [ 03/19/14 ]
The new study by Bryan D. James, PhD, et al (including BrightFocus-funded Kristine Yaffe, MD), was published online in Neurology on March 5, 2014. There are a couple of explanations for why their estimates of deaths differ from the official figures reported by CDC.
The researchers performed a statistical analysis, then applied their results to similar age groups in the U.S. population. Their findings have to be interpreted with caution because:
- The study results are an estimate of deaths from AD—and not an actual count.
- The study population may not accurately depict the U.S. population.
For example, the analysis was based on data from 2,566 people enrolled in two previous clinical trials. Each participant received regular medical care and was diagnosed with AD in timely fashion. In contrast, many elderly people in the U.S. don’t receive regular medical care and often their AD symptoms go undiagnosed.
In addition, these researchers derived their estimate from people aged 75 years and older. This group had already survived the most common “killers” in old age—heart attack, stroke, and cancer and thus might have been more likely to die from Alzheimer’s than other diseases. The researchers themselves recognize these possible biases in their study and call their estimate “crude.” They suggest the truth may lie somewhere between their estimate and CDC’s data.
Mortality Reporting—An Imperfect Science
It is widely acknowledged that deaths from Alzheimer’s disease tend to be undercounted due to standard reporting mechanisms. CDC mortality figures are drawn from information on death certificates, where one cause of death is listed. Right now, this is the best way to count the actual numbers of death in the U.S., which is different from using statistical predictions based on the general population. Unfortunately, however, listing one cause on the death certificate doesn’t capture the reality of dying for many elderly people, when there may be multiple factors at play.
Alzheimer’s disease, in particular, contributes to death over a period of years. People with AD have difficulty shopping for food, planning meals, and caring for themselves in the most basic ways, including sleeping, eating, and protecting themselves from accidents and falls. Eventually they have difficulty managing their own health problems and their general health may decline because they are too disoriented to seek care from a doctor or take medications they need for a chronic condition.
The list of problems grow deadlier: in advanced stages, Alzheimer’s disease is linked to difficulties with swallowing and severe malnutrition. That, in turn, can lead to life-threatening illnesses, such as pneumonia. If one illness or infection proves fatal, the immediate cause of death (for example, “pneumonia” or “sepsis”) is written on the death certificate. Alzheimer’s disease is then omitted as an underlying cause. Many groups, including BrightFocus Foundation, think it’s time for comorbidities or more than one cause of death to be listed on the death certificate. Until that happens, Alzheimer’s disease and its impact on the very end of life may be drastically underrepresented.
Is Alzheimer's disease hereditary? [ 08/30/13 ]
Familial Alzheimer's disease (FAD) or early-onset Alzheimer's is an inherited, rare form of the disease, affecting less than 10 percent of Alzheimer's disease patients. FAD develops before age 65, in people as young as 35. It is caused by one of three gene mutations on chromosomes 1, 14 and 21. If even one of these mutated genes is inherited from a parent, the person will almost always develop FAD. All offspring in the same generation have a 50/50 chance of developing FAD if one parent has it.
The majority of Alzheimer's disease cases are late-onset, usually developing after age 65. Late-onset Alzheimer's disease has no known cause and shows no obvious inheritance pattern. However, in some families, clusters of cases are seen. Although a specific gene has not been identified as the cause of late-onset Alzheimer's disease, genetic factors do appear to play a role in the development of this form of the disease. A gene called Apolipoprotein E (ApoE) appears to be a risk factor for the late-onset form of AD. There are three forms of this gene: ApoE2, ApoE3 and ApoE4. Roughly one in four Americans has ApoE4 and one in twenty has ApoE2. While inheritance of ApoE4 increases the risk of developing AD, ApoE2 substantially protects against the disease.
Scientists believe that several other genes may influence the development of Alzheimer's disease. Two of these genes, UBQLN1 and SORL1, are located on chromosomes 9 and 11. Researchers have also identified three genes on chromosome 10, one of which produces an insulin degrading enzyme that may contribute to the disease. A gene, called TOMM40, appears to significantly increase one's susceptibility to developing Alzheimer's when other risk factors are present, such as having the ApoE-4 gene. Several recently discovered genes that influence Alzheimer's disease risk are CLU (also called APOJ) on chromosome 8, which produces a protein called clusterin, PICALM on chromosome 11 and CR1 on chromosome 1.
In October of 2013, an international group of researchers reported on the identification of 11 new genes that offer important new insights into the disease pathways involved in Alzheimer's disease.The new genes (HLA-DRB5/HLA0DRB1, PTK2B, SLC24A4-0RING3, DSG2, INPP5D, MEF2C, NME8, ZCWPW1, CELF1, FERMT2 and CASS4) add to a growing list of gene variants associated with onset and progression of late-onset Alzheimer's.
Genetic risk factors alone are not enough to cause the late-onset form of Alzheimer's disease, so researchers are actively exploring education, diet and environment to learn what role they might play in the development of this disease.
What are the stages of Alzheimer's disease? [ 08/30/13 ]
The following stages represent the general course the disease follows, but moving from one stage to another may not be perceptable due to the fact that the symptoms are on a gradual continuum of severity.
Physical conditions connected to Alzheimer’s disease exist in a person’s body long before symptoms are evident. These conditions are normally defined through the use of “biomarker” tests, like those searching for beta-amyloid and tau proteins in blood and cerebrospinal fluid, and specialized PET and MRI scans. Currently, this stage is only defined in research settings and clinical trials and is unlikely to be given as an official clinical diagnosis by a health professional.
Mild Cognitive Impairment (MCI) Due To Alzheimer’s Disease/Prodromal Stage:
Recently, scientists have identified a condition between normal age-related memory loss and dementia called mild cognitive impairment (MCI). Individuals with MCI have persistent memory problems (for example, difficulty remembering names and following conversations and marked forgetfulness) but are able to perform routine activities without more than usual assistance. MCI often leads to Alzheimer’s, but while all those who progress to some form of dementia go through a period of MCI, not all patients exhibiting MCI will develop Alzheimer’s disease. An official clinical diagnosis of MCI can be given by a health professional.
Dementia Due To Alzheimer’s Disease (Mild, Moderate, Severe Stages):
Mild (Stage 1)
Early in the illness, people with Alzheimer’s tend to lose energy and spontaneity, though often no one notices anything unusual. They exhibit minor memory loss and mood swings and are slow to learn and react. After a while they start to shy away from anything new and prefer the familiar. In this stage, Alzheimer’s patients can still perform basic tasks independently but may need assistance with more complicated activities. Speech and understanding become slower, and patients often lose their train of thought in midsentence. They may also get lost while traveling or forget to pay bills. As they become aware of this loss of control, they may become depressed, fearful, irritable, and restless.
Moderate (Stage 2)
Eventually, people with the illness begin to be disabled by it. Though the distant past may be recalled, recent events become difficult to remember. Advancing Alzheimer’s affects the ability to comprehend location, the day, and the time. Caregivers must give clear instructions and repeat them often. As Alzheimer’s patients’ minds continue to slip away, they may invent words and not recognize formerly familiar faces.
Severe (Stage 3)
During the final stage, patients become more and more unresponsive. Memory becomes so poor that no one is recognizable. Patients lose bowel and bladder control and eventually need constant care. They lose the ability to chew and swallow and become bedridden and vulnerable to pneumonia, infection, and other illnesses. Respiratory problems worsen, particularly when the patient becomes bedridden. This terminal stage eventually leads to coma and death.
Who should I go to if I suspect I may have Alzheimer's disease? [ 08/30/13 ]
First, visit your regular family physician. The physician will probably do a variety of tests to determine the probability of Alzheimer's. Specialists such as neurologists, gerontologists and geriatric psychiatrists may also be involved in the evaluation process.
What kind of information should I bring to my first visit to the doctor? [ 08/30/13 ]
If you visit a new doctor, bring your medical records; for any doctor, bring a list of over the counter and prescription medicines you are currently taking. If you don't know the names of the drugs, bring the pill bottles with you. A medication or a combination of medications can sometimes cause symptoms that resemble Alzheimer's disease. Also make a list of current medical problems. It's a good idea to show the doctor a list of symptoms, behaviors and any problems carrying out routine activities (for example, paying bills) in yourself or your loved one that concern you.
How is Alzheimer’s disease diagnosed? [ 08/30/13 ]
While an autopsy can confirm the presence of the disease, skilled physicians can correctly diagnose Alzheimer's disease about 90 percent of the time based on mental and behavioral symptoms, a physical examination, and neuropsychological and laboratory tests. Scientists have recently developed a number of new biomarker and brain scanning techniques that may help to improve diagnosis.
Mentally, having trouble following instructions, losing one's orientation, displaying poor judgment, and having difficulty managing money, shopping, or driving are all possible symptoms of Alzheimer's disease.
The physical exam will usually include a general physical, blood tests, and urinalysis. The doctor can use such test results to eliminate other forms of dementia—for instance, certain vitamins and hormones can provoke symptoms of dementia if they are present in too little a quantity. Brain scans can rule out non-Alzheimer's disease dementia and can reveal structural changes present in Alzheimer's disease.
The physician will determine whether neuropsychological testing is called for to examine memory, attention, math calculations, language and other intellectual functions.
The place to start is with one's own physician, who may then suggest specialists to do further testing.
How long does Alzheimer's disease last on average? [ 08/30/13 ]
On average, patients with Alzheimer's disease live for 8 to 10 years after diagnosis. However, this terminal disease can last for as long as 20 years.
Is there a test to detect a predisposition to Alzheimer's? [ 08/30/13 ]
There is a test currently available that can identify which forms of apolipoprotein (ApoE) are present in the blood. One form, ApoE4, is associated with an already well-studied condition, heart disease, and appears to increase the risk of developing Alzheimer's as well. However, this blood can only detect whether ApoE4 is present, not if and when the person will develop Alzheimer's.
In 2007, researchers at Stanford University published some promising study results in which 18 blood proteins (and resultant chemical signals) were tested to determine the risk of advancement from mild cognitive impairment (MCI) to Alzheimer's disease. In the study, the scientists were able to predict whether the subjects would progress to Alzheimer's with 90% accuracy. However, this study tested a relatively small number of people, and larger studies will need to be undertaken.
Disclaimer: The information provided here is a public service of the BrightFocus Foundation and should not in any way substitute for the advice of a qualified healthcare professional; it is not intended to constitute medical advice. Please consult your physician for personalized medical advice. BrightFocus Foundation does not endorse any medical product or therapy. All medications and supplements should only be taken under medical supervision. Also, although we make every effort to keep the medical information on our website updated, we cannot guarantee that the posted information reflects the most up-to-date research.
Some of the content in this section is adapted from other sources, which are clearly identified within each individual item of information.
Last Review: 08/21/13