Alzheimer’s Disease: Overview

Abstract

September 2016 marked the fifth ―World Alzheimer’s Month‖ with the theme ―Remember Me‖. Events
were held by Alzheimer's associations and others in over 70 countries worldwide with the support of
Alzheimer's Disease International. Alzheimer's disease (AD), also known as Alzheimer disease, or
just Alzheimer's, accounts for 60% to 70% of cases of dementia. It is a chronic neurodegenerative disease
that usually starts slowly and gets worse over time. The most common early symptom is difficulty in
remembering recent events (short-term memory loss). As the disease advances, symptoms can
include problems with language, disorientation (including easily getting lost), mood swings, loss
of motivation, not managing self care, and behavioural issues. As a person's condition declines, they often
withdraw from family and society. Gradually, bodily functions are lost, ultimately leading to
death. Although the speed of progression can vary, the average life expectancy following diagnosis is
three to nine years. The cause of Alzheimer's disease is poorly understood. About 70% of the risk is
believed to be genetic with many genes usually involved. Other risk factors include a history of head
injuries, depression, or hypertension. The disease process is associated with plaques and tangles in
the brain. A probable diagnosis is based on the history of the illness and cognitive testing with medical
imaging and blood tests to rule out other possible causes. Initial symptoms are often mistaken for normal
ageing. Examination of brain tissue is needed for a definite diagnosis. Mental and physical exercise, and
avoiding obesity may decrease the risk of AD. There are no medications or supplements that decrease
risk. No treatments stop or reverse its progression, though some may temporarily improve
symptoms. Affected people increasingly rely on others for assistance, often placing a burden on
the caregiver; the pressures can include social, psychological, physical, and economic elements. Exercise
programs are beneficial with respect to activities of daily living and can potentially improve
outcomes. Treatment of behavioral problems or psychosis due to dementia with antipsychotics is common
but not usually recommended due to there often being little benefit and an increased risk of early death.
In 2010, there were between 21 and 35 million people worldwide with AD. It most often begins in people over 65 years of age, although 4% to 5% of cases are early-onset Alzheimer's which begin before this. It
affects about 6% of people 65 years and older. In 2010, dementia resulted in about 486,000 deaths. It was
first described by, and later named after, German psychiatrist and pathologist Alois Alzheimer in
1906. In developed countries, AD is one of the most financially costly diseases.