Alzheimer’s disease is the most common cause of dementia. Dementia is a term used to describe various different brain disorders that have in common a loss of brain function that is usually progressive and eventually severe. There are more than 100 types of dementia. Dementia is not a normal part of aging. It doesn’t know social, economic, ethnic or geographic boundaries.
Although each person will experience dementia in their own way, eventually those affected are unable to care for themselves and need help with all aspects of daily life. There is currently no cure, but treatments, advice, and support are available.
Alzheimer’s disease destroys brain cells and nerves disrupting the transmitters which carry messages in the brain, particularly those responsible for storing memories. During the course of Alzheimer’s disease, nerve cells die in particular regions of the brain. The brain shrinks as gaps develop in the temporal lobe and hippocampus, which are responsible for storing and retrieving new information. This in turn affects people’s ability to remember, speak, think and make decisions.
The production of certain chemicals in the brain, such as acetylcholine is also affected. It is not known what causes nerve cells to die but there are characteristic appearances of the brain after death. In particular, ‘tangles’ and ‘plaques’ made from protein fragments are observed under the microscope in damaged areas of brain. This confirms the diagnosis of Alzheimer’s disease.
What are the symptoms of Alzheimer's Disease?
Typically, Alzheimer’s disease begins with lapses of memory, difficulty in finding the right words for everyday objects or mood swings. As Alzheimer’s disease progresses, the person may:
- Routinely forget recent events, names and faces and have difficulty in understanding what is being said.
- Become confused when handling money or driving a car.
- Undergo personality changes, appearing to no longer care about those around them.
- Experience mood swings and burst into tears for no apparent reason, or become convinced that someone is trying to harm them.
In advanced cases people may also:
- Adopt unsettling behavior like getting up in the middle of the night or wander off and become lost.
- Lose their inhibitions and sense of suitable behavior, undress in public or make inappropriate sexual advances.
Who is at risk of Alzheimer's Disease?
It is unlikely that there is a single cause of Alzheimer’s disease. Researchers believe that many factors, including age, genetic background and lifestyle, work together and lead to the onset of the disease. They include:
One in 50 people between the ages of 65 and 70 have a form of dementia, compared to one in five people over the age of 80. Factors associated with aging may be responsible for this increased risk.
Women are slightly more likely to develop Alzheimer’s disease than men. A lack of the hormone oestrogen in women after the menopause has been suggested as one factor in the development of Alzheimer’s disease.
In the majority of cases the effect of inheritance seems to be small, such that if a parent or other relative has dementia your own chances of developing it are only a little higher than if there were no cases of dementia in the family.
Diet can affect a person’s risk of developing many types of illness, including dementia. A healthy and balanced diet, which enables a person to maintain a normal body weight, is likely to reduce the likelihood of developing high blood pressure or heart disease, both of which put a person at greater risk of developing dementia.
Smoking has an extremely harmful effect on the heart, lungs and vascular system, including the blood vessels in the brain. This increases the risk of developing dementia.
People who drink excessive amounts of alcohol over a long period of time increase their risk of developing a form of dementia.
People who suffer severe or repeated head injuries – in a car accident, for example – are at a three- to four-fold increased risk of developing dementia.
What preparations are necessary for an Alzheimer's Screening?
To complete an Alzheimer’s screening, Hill Medical radiologists will need to use PET/CT scan equipment. Some PET/CT scans require no preparation at all, while others might require you to modify your food, fluid, or medication intake prior to the Alzheimer‘s screening.
If possible, try to wear loose-fitting clothes on the day of your scan, and avoid caffeine so you won’t be restless. During the Alzheimer’s screening, all you have to do is relax, and lie as still as you can. You will first receive a small injection of a radiopharmaceutical contrast about 60 minutes before the actual scan. It will not make you feel any different.
Depending on the type of study, you may also receive a contrast medium at the time of the CT portion. This is a dye that increases the quality of the CT images. The contrast medium may be administered orally, or by injection, or both. Some patients report a warm feeling or an unusual taste in their mouth from the contrast medium.
Should I tell the technologist about my medical history?
Yes. Before you are given a radiopharmaceutical or a contrast medium, be sure to tell the technologist if you have allergies, asthma, heart problems, diabetes, or kidney problems; if you think you might be pregnant; or if you are currently undergoing any radiation therapy.