Alzheimer's Disease

Major Symptoms

Loss of short term memory is the first sign of Alzheimer's disease. Later on, changes in mood and changes in personality develop. In the middle stages of the disease, people begin to have difficulty in driving, taking care of their finances and themselves, and all sorts of practical daily live routines.

This site is not only about Alzheimer's, it is about dementia too. Dementia and Alzheimer's disease are two sides of the same coin, and two-thirds of all cases of dementia are due to Alzheimer's.

A characteristic of the disease is that the patient's ability to make new memories is impaired, and their ability to learn new things is greatly reduced.

Incidence, Prevalence, and Statistics

In a famous study (Ott et al. 1995), also known as the Rotterdam Study, 474 cases of dementia were detected in a population of 7,528 persons. Of the 474 cases of dementia, 339 were due to Alzheimer's disease. Vascular dementia counted for 76 cases (16%), and Parkinson's dementia applied to 30 cases, or 6% (Fig. 1). The study showed that the prevalence of dementia at age 55-59 was 0.4% of the population while it was 43.2% in those older than 94. The study showed that the number of Alzheimer's incidences increased with age.


The study also found that the prevalence of dementia in people with a low level of education was significantly higher than in those better educated. The reason could be that people with a higher income can afford food of a better quality and have more time for exercise.

Causes of dementia - only two-thirds are caused by Alzheimers's

Fig 1. Causes of Dementia in 474 Individuals

Dementia and Alzheimer's are often used confused with one another, as Alzheimer's is the major cause of dementia, which is what most people see in the elderly.

Dementia is a general descriptive term, so to say someone has dementia is to say a person has persistent memory loss or loss of cognitive functions that are sufficient to hinder the person in doing his or her normal daily life activities.

Alzheimer's is a specific brain disorder, which is one of many disorders that can cause dementia. The two terms are not mutually exclusive; they are just two different levels of meaning.

People with dementia may also have a number of other brain diseases, such as Parkinson's disease, while others may have suffered from a stroke.

Below is a list of some of the other causes of dementia than Alzheimer's:

Vascular Dementias (Multi-infarct or Post-stroke Dementia)

Dementia can be onset by a stroke, which is due to a period of reduced or no air supply to the brain. The affected brain tissue is therefore destroyed, and the brain cells of the area die and cannot be regenerated. This condition of reduced or no air supply to the brain is also known as ischemia.

Dementia caused by strokes or heart infarcts accounts for 15 % to 20 % of all cases of dementia. Although a number of people will have a combination of Alzheimer's and vascular dementia, the two should basically be divided.

Vascular dementia manifests itself much faster than Alzheimer's, as the stroke or heart infarcts are the direct cause of the dementia. Therefore, dementia can be present in anyone in a very short period—all that's needed is ischemia.

Also, vascular dementia is not related to age the same way as Alzheimer's is, although heart infarcts and strokes in younger individuals are usually much milder and less damaging than in the elderly. The incidence of heart attacks or strokes in young individuals is much lower than in the elderly.

Risk factors for vascular dementia are the usual suspects: high blood pressure, abnormal heart rhythms, sleep apnea (some people occasionally stop breathing for periods while asleep), diabetes, smoking, too high blood cholesterol, and artery and coronary diseases.

Parkinson's Dementia

Within eight years of diagnosis, approximately 80% of Parkinson's disease patients will have some symptoms of dementia. The reason is that some brain cells are destroyed in Parkinson's patients, which unfortunately causes symptoms of dementia. The symptoms are very similar to symptoms from Lewy body dementia.

HIV and AIDS Dementia

HIV and AIDS can also cause mild forms of dementia. The virus will, to some extent, damage nerve cells inside the brain and give dementia symptoms, such as memory loss.

Pick's Disease (Frontal Temporal Dementia)

The main symptoms of Pick's disease are disruption of speech and a strange loss of ability to control oneself. The latter leads to impulsive behavior, and a person with Pick's disease will do things they would normally not do, such as saying things that are sexually very explicit or behaving promiscuously.

Another symptom is that the suffering patient has difficulties in finding words and suddenly finds it difficult to understand language. Others who were previously very outgoing suddenly become depressed and introverted.

The areas affected in Pick's disease are the frontal and temporal side of the brain (front and side). Sometimes the disease is called frontal temporal dementia, which in some people's opinion better describes what the disease is all about.

Alcohol dementia

This only affects long-time drinkers of alcohol, and it is also known as Korsakoff's syndrome. For reasons unknown, people with this type of dementia will try to cover up their lapses in memory by making things up.

For people with Korsakoff's syndrome, it is impossible to learn new things right from the onset of the disease. This is worse than for Alzheimer's patients.

Alcohol dementia can be partly treated by having people stop drinking. However, complete and sudden withdrawal from alcohol can have detrimental side effects, also known as delirium tremens. The detoxification process needs to last for a short period of time. When the drinking stops, the patient’s dementia will stop getting worse, and it will even reverse a little. However, when the damage has already happened, the patient will always suffer from some degree of dementia due to the heavy drinking.


Before 1940 and the common use of penicillin, syphilis was the most common cause of dementia in the Western world. Since then, syphilis-induced dementia has not been a problem. However, to exclude syphilis for being the causative agent of dementia, people with dementia are sometimes tested for the syphilis-causing bacteria.

Alexander the Great probably suffered from this type of dementia.

Reversing Dementia

Less than 1% of all cases of dementia can be reversed if treated correctly and in a timely manner, which is also one of the reasons why it is so important to get an early diagnosis. While less than one percent is not that high, when viewed from a numerical population perspective, a great deal can actually be cured of their dementia.

Alzheimer's Risk Factors

The main reason for the increase in Alzheimer's patients in the Western world is the fact that more people are living longer. Baby boomers are coming into an age where they can get Alzheimer's.

For the next 25 years, we will continue to see an increase in the number of Alzheimer's patients.

40 years ago people had the same risk of getting Alzheimer's as they do today, but because they didn't live for that long, fewer people got the disease, and therefore Alzheimer's disease was not very well known.

Years ago, and even now, Alzheimer's was called senile dementia and was looked at as a natural part of the aging process, at least for some people. Also, senile dementia was looked at as something people got as a side effect of other common diseases among the elderly.


Memory peaks quite early in life. The peak is probably in the late twenties or early thirties, where people peak both mentally and physically. When we get a little older, we begin getting sloppy, and we begin to experience everyday memory losses.

However, normal forgetfulness should not be mistaken with Alzheimer's or dementia. It is fairly normal to forget where you put your car keys, but it isn't normal if you tend to forget what the car keys are used for. This is what happens to Alzheimer's patients or people with dementia; they lose their orientation in the world.

Lifestyle can also increase or decrease the chances of getting Alzheimer's. Diabetes, hypertension, cholesterol, and obesity are all factors that increase the chances of getting Alzheimer's. The Rotterdam study showed that the number of Alzheimer's incidences was related to education. Diabetes, cholesterol levels, hypertension, and obesity are to some extent related to educational level too.

Healthy eating and regular exercise will not only reduce the chance of getting Alzheimer's but will delay the onset of symptoms and the progression of the disease and prevent or delay the outbreak of lots of other diseases.

Early Onset of Alzheimer's

Luckily, the early onset of Alzheimer's disease is uncommon. However, vascular dementia occurs in all ages. People with Down's syndrome usually have dementia before they reach the age of forty.

In contrast to Parkinson's disease, where a few people are also affected before the age of 40, Alzheimer’s is by and large a disease for the elderly. Early onset Alzheimer's disease cannot be compared, by any means, to early onset Parkinson’s disease. The biggest risk factor in Alzheimer's is increasing age.

Alzheimer's Societies

The Alzheimer's Society is invaluable in helping patients and people related to Alzheimer's patients. Therefore, it can be a good idea to support any Alzheimer's disease society in your local area. The society not only helps Alzheimer's patients; they also help direct funds to research for finding a cure for Alzheimer's or slowing the progression of Alzheimer’s. The Society also helps people live better lives with Alzheimer's, as well as giving advice and options to relatives of the patient.

Alzheimer's Research

Research into Alzheimer's and other brain disorders is done on a much better basis today than just a few years ago due to a vastly increased knowledge in the field of brain physiology. Much of the research focuses on those proteins of the brain (amyloid) that are characteristic of Alzheimer's patients, and many prospective treatment types look at how this amyloid protein can be inhibited one way or another. It is probably a few years down the road before such treatments are coming, but don't be surprised if they are here soon.

Alzheimer Disease Pathology

The disease is reflected in changes in structures of the brain that are responsible for memory and the ability to learn. The centers simply shrink, and the cells in those centers die out.

If one looks at brain pictures in healthy individuals and Alzheimer's patients, one can really see that some of the areas of the brain in those with Alzheimer’s have almost dried out or shrunk.

In the beginning of Alzheimer's, the loss of brain cells is slow, and the process can be slowed significantly with the help of medicine. However, the problem is not only that cells die out. The communication between the affected areas of the brain and the rest of the brain is impaired.

Economical Impact of Alzheimer's Disease

Alzheimer’s is one of the most devastating degenerative neurological disorders. The earlier the disease is diagnosed the better, as there is medicine that can delay the progression of the disease. More than 4 million Americans suffer from the disease. In the future when the age distribution changes, it is estimated that the number may rise to more than double.

In costs, Alzheimer's comes after cancer and heart diseases when counting direct and indirect costs associated with the diseases. In the U.S., Alzheimer's is estimated to cost something in the range of $150 billion a year.

Alzheimer’s also results in a deterioration across functional, behavioral, and cognitive domains. Most people know it affects memory, but much more is changed. It can result in a loss of judgment, loss of language function, and a reduction in the ability to do normal daily tasks, such as cooking, undressing, and keeping a checkbook.

It can also result in depression and anxiety.


See the section about tests for more information about how Alzheimer's is diagnosed.

If there is suspicion of Alzheimer's, the doctor will probably also have an MIR scan done.

Several medications are effective at slowing the progression of the disease. It is therefore very important that the diagnosis is made as early in the process as possible.


All sort of worries are normal for Alzheimer's disease patients. The worries are often about when they will reach a stage when they don't know how to get out of the house or when they are going to lose their sense of direction. Often Alzheimer’s starts with people noticing that they get forgetful and cannot remember places, names, and addresses when they were going to meet somebody. In the beginning, most people just assume it as being a part of aging, not something more serious than forgetfulness.


1. Alewijn Ott et al."Prevalence of Alzheimer's disease and vascular dementia: association with education. The Rotterdam study" British Medical Journal Volume: 310(6985) pp. 970-973 (1995)

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