Types of Dementia
Alzheimer's disease is the most common cause of dementia. It was first identified in 1906 by a German neurologist named Alois Alzheimer. In 2001, 22 million people suffered from Alzheimer's disease worldwide. Occurring most often in the elderly population, the likelihood of developing Alzheimer's disease doubles every five years after the age of 65.
Currently, there is no known, single cause of Alzheimer's disease. However, research has found certain genes that are thought to play a role. Previous head injuries have also been linked to Alzheimer's disease in some cases. As well, studies have shown that Alzheimer's disease occurs slightly more often in women than in men.
Alzheimer's disease slowly and progressively destroys portions of the brain. In the early stages of this disease, it may be difficult to decide whether a person's forgetfulness is a sign of Alzheimer's disease or a sign of normal aging. As the disease progresses and simple activities become more and more difficult, it becomes apparent that Alzheimer's disease is not part of the normal aging process. Alzheimer's disease typically decreases a person's life span. After diagnosis , a person is generally expected to live an average 8-10 years with the disease.
The progression of Alzheimer's disease is similar in most people. As the disease progresses, a person will experience new symptoms and an increase in the severity of older symptoms. However, there are a wide range of possible symptoms and they tend to vary from person to person. Alzheimer's disease is generally thought of in three stages: mild, moderate and severe. Often family and friends are the first to notice early symptoms of the disease and the most common first problem is forgetfulness. As the damage in the brain increases, the person's mental ability becomes impaired, affecting their performance at home, at work or in favourite activities.
Source: Alzheimer's Disease International (2009). World Alzheimer Report.