Alzheimer's disease has a major impact on the health of Canadians. About 500,000 Canadians suffer from some type of dementia (mental deterioration), and 60% of these have Alzheimer's disease. About 60% of people in long-term care facilities have Alzheimer's disease, and 1 in 5 people with Parkinson's disease will develop it. The US Alzheimer's Society estimates that about $90 billion is spent annually in medical treatment and nursing home care, lost productivity, and early death due to Alzheimer's disease.
There will be over 1 million Canadians living with dementia by the year 2038, largely because the "baby boom" generation (people born between 1946 and 1960) will have reached old age.
We still don't understand exactly how Alzheimer's disease damages the brain. Somehow, cells are damaged and eventually die in different areas of the brain. The damaged areas of the brain contain abnormalities called senile plaques and neurofibrillary tangles. The death of brain cells leads to dementia, characterized by memory loss, impaired judgment, and behavioural changes.
Eventually, the person loses their speech as well as their bladder and bowel control. People with Alzheimer's typically die of infections such as pneumonia or other medical problems. Most people live for about 7 years after diagnosis, but some have lived for up to 20 years.
Each case of Alzheimer's usually affects at least two lives: the person with the condition, and the patient's spouse or child who gradually becomes a full-time caregiver as the disease progresses. Caring for an individual with Alzheimer's can be demanding and stressful. Many caregivers must eventually face the difficult decision of placing their loved one in institutional care.
With Alzheimer's, we look more at risk factors than direct causes.
There may be a genetic factor in Alzheimer's disease, since we know it runs in some families. Researchers have even found a gene that causes a particularly severe form of the disease. If you inherit this gene from only one parent, you have an increased chance of getting Alzheimer's disease, compared to people with the normal gene. Inheriting it from both parents means you'll almost certainly get the disease, and at an earlier age.
Familial autosomal dominant Alzheimer's disease (FAD) is the name given when Alzheimer's disease is clearly passed on from generation to generation in a family. It typically comes on before the age of 60, and the Alzheimer's gene, called APOE e4, turns up in many family members. FAD only explains about 6% of all Alzheimer's disease cases, however.
Another type of Alzheimer's disease, sporadic Alzheimer's disease, also runs in families, but to a much lesser degree. It rarely appears before the age of 70. If one of your parents had Alzheimer's disease but didn't carry the APOE e4 gene, your risk is only slightly higher than that of the general population.
Even if no one in your family has had Alzheimer's, you can still get sporadic Alzheimer's disease. Most researchers believe there are other genes that can make people susceptible to Alzheimer's disease, but genes alone aren't enough - some other trigger has to set off the disease process.
Possible risk factors include:
Mild forgetfulness is normal with advancing age, but healthy older people are usually good at remembering what's most important to them. There is reason for concern if they start forgetting what they were just doing, get lost in their own neighbourhood, or start displaying uncharacteristic or inappropriate behaviour. If your husband is always misplacing his keys, it may mean nothing. If he starts leaving them in the fridge or the sugar bowl, it may be cause for concern.
One of the most recognizable symptoms of Alzheimer's disease is a speech problem, such as a person choosing the wrong words, or not understanding simple sentences. Problems with numbers are also common. These are the most reliable signs of early-stage Alzheimer's disease. Other early signs include forgetfulness about recent events (loss of short-term memory), trouble with tasks such as housework or balancing a chequebook, and poor judgment.
In the later stages, people with Alzheimer's disease begin to have trouble caring for themselves and recognizing friends or loved ones. They may become confused, agitated, or aggressive.
The Alzheimer's Society of Canada lists these 10 warning signs to be aware of: