The term dementia refers to any medical condition where cognitive function is altered. There are many types of dementia, but the most common and well-known is Alzheimer's disease, which accounts for approximately 60 percent of cases. The risk of developing this disease grows significantly with age, reaching nearly 20 percent in individuals aged 80 and over.
This type of dementia is characterized by the progressive onset of memory deficits, as well as impairment in language and various intellectual functions that allow us to act, think and understand.
Many changes take place in the brain structure of persons suffering from Alzheimer's disease. Some cells shrink, while others disappear. Upon examination of the brain, dense and irregular spots are noted; over time, these spots can overrun healthy brain cells.
The exact cause of these changes remains unknown. However, research has led to the identification of a few factors that may have an influence on the progression of the disease. For example, it is believed that certain brain cells that produce a chemical messenger called acetylcholine decline as the disease progresses. Without the acetylcholine normally produced by the cells, intercellular communication in the brain is greatly compromised. Since we know that acetylcholine is involved in memory processes, its scarcity could increase the memory loss associated with Alzheimer's disease.
Signs and symptoms
Alzheimer's disease can be difficult to live with because has a global effect – it doesn’t just affect their behaviour and autonomy, it affects their thoughts and emotions as well. As the lesions spread, persons affected show a noticeable decrease in various functions and abilities.
The first thing noted is a loss of short-term memory, which progresses from occasional to increasingly frequent. Amnesia is the first symptom to manifest in most cases.
Next comes a gradual loss of autonomy; persons affected find it increasingly difficult to perform familiar tasks as simple as preparing a meal or doing laundry. Some individuals experience speech difficulties, called aphasia, causing them to forget certain words or choose inappropriate vocabulary.
In advanced cases of the disease, total aphasia is common. Individuals may feel disoriented in time and space and familiar locations become difficult to identify. Personality changes begin to appear, as the person becomes gradually more confused, distrustful, withdrawn and moody without any apparent reason. A general lack of interest is also noted; over time, the person with Alzheimer’s becomes passive and resistant to stimulation. In other words, personality, memory and the ability to function all progressively decline as the disease progresses. Parallel to this gradual loss of autonomy, persons affected begin to require more and more care and attention, since they are no longer able to function on their own.
While Alzheimer’s disease causes a lot of important changes, it is important to remember that the ability to feel emotions – including joy, anger, fear, love or sadness – and most importantly, the ability to react to these feelings, are not affected by the illness, no matter what stage it has reached.
These signs and symptoms are not part of the normal aging process. Since early diagnosis can have a positive impact on the disease progression, it is important to see a doctor as soon as one or more of the above symptoms appears. Loss of memory in individuals over the age of 65 can therefore be a reason for consulting a physician if it alters their social or functional capacities. Such changes should be clinically evaluated by a physician.
It is important to eliminate any secondary cause that could produce similar symptoms, such as cerebral vascular disease, a vitamin B12 deficiency, alcoholism or the use of certain medications that act on the central nervous system and that can cause confusion, particularly in the elderly.
Since Alzheimer’s is a degenerative disease, its characteristic symptoms appear gradually, not suddenly. The disease progression varies from one person to another; it can span three to twenty years, with an average survival time of eight to twelve years.
The disease progression can be evaluated using a three-phase scale (early, moderate and advanced) or using another method that divides the disease into seven stages (the Reisberg scale). The care to provide to persons affected will vary based on where they are in the various stages of disease progression. When it comes to the onset of symptoms and duration of the phases, each person evolves differently.
To this day, there is no curative treatment for Alzheimer’s. The few medications currently on the market can only at best slow the disease progression, without stopping the brain cell degeneration process. They act by altering the function of the enzyme that is responsible for the degradation of acetylcholine By preserving the acetylcholine in the brain, these drugs can temporarily delay the disease progression. Their effects are often modest and quickly disappear when the treatment is stopped.
It is beneficial to introduce medication as soon as Alzheimer’s symptoms appear, as this is when drugs are most effective. Parallel with these treatments, it is also essential to provide moral support to those affected, as well as to their caregivers.
Research in this area is currently underway to broaden our therapeutic arsenal, and other molecules will probably be available within a few years.
The progression of Alzheimer’s disease in a loved one can be very difficult to bear for the family. As the disease progresses, persons affected become increasingly dependent, to the point of requiring total care. The major personality changes that accompany this slow physical degradation can add a psychological burden that can be potentially difficult to handle for the family. Whether you are a family member or a friend, a volunteer or a health care professional, you may one day feel exhausted by the complex nature of such a task.
Various resources are available for both you and the person affected. The Alzheimer Society of Canada is a dependable resource. Its site offers a wealth of information, news and discussion forums, in both English and French. In addition, the provincial levels of this organization offer support groups, a telephone help line, resource centres and education programs, among other services. Contact the Society’s regional office for more information.
Don’t hesitate to consult the organization or your health care professional if the need arises!