Dementia is the loss of ability to think due to the impairment of memory. Generally used to describe an abnormal part of the ageing process. There are many different types of dementia, and many different causes.

Alzheimer’s disease (AD) is the most common cause of dementia. Because its frequency increases with age, the number of people it strikes is growing as the population ages. In addition to memory loss, the first signs of Alzheimer’s often include language difficulties and trouble with routine activities, such as driving and shopping. Mood changes may also occur. As the disease progresses, long-term memory may also be affected, and behavioural changes such as aggression, agitation, delusions and verbal outbursts may occur. The ability to carry out daily tasks, such as dressing or bathing, may be compromised. In severe Alzheimer’s, the abilities to talk and walk may be lost.Causes of Alzheimer’s Disease

Alzheimer’s is a neurodegenerative disease, which means neurons (brain cells) progressively degenerate, eventually losing function and dying. Cells in the hippocampus, a seahorse-shaped structure deep in the brain that plays a major role in the formation of memories, appear to be especially vulnerable. In brain-imaging studies of people with Alzheimer’s, the hippocampus is consistently smaller than normal. Accumulation of beta amyloid in nerve cells, in between the nerve cells and in the small blood vessels, together with vascular changes and possibly inflammation, are features of AD. There may be an inherited predisposition, but no specific cause has been identified in AD. The symptoms start insidiously and progress steadily over 10-20 years.

The brain pathways that link the hippocampus to other brain regions are also damaged, especially for those that lead to the prefrontal cortex, the brain’s control centre for cognitive functions. Many scientists believe this damage may be responsible for the persistent short-term memory problems that appear in the early stages of the disease.

Each person with Alzheimer’s may experience different symptoms, and symptoms may change over the course of the disease. Some of the common ones are described below.

The earliest signs of Alzheimer’s disease are usually first noticed by a friend or relative. If yosomeone close to you is experiencing any of the symptoms listed in “Common Symptoms of Alzheimer’s Disease”, it is important to see a doctor as early as possible to determine the cause. Memory loss could be the result of a number of things, many of which may be reversible.

Currently, the only definitive diagnosis for Alzheimer’s disease is based on an examination of brain tissue during autopsy. To establish a clinical diagnosis, doctors focus on ruling out, by process of elimination, all other possible causes of symptoms to determine whether AD might be the cause.

If these initial examinations don’t reveal a clear problem, additional tests might include:

A diagnosis of Alzheimer’s disease is usually said to be either:

Probable: All other disorders that may cause dementia have been ruled out; or

Possible: AD is suspected, but other causes cannot be ruled out

As science progresses toward a better understanding of what kills brain cells in Alzheimer’s disease, the hope is that medicines or other therapies might be developed to delay, prevent or reverse the damage. Clinical trials are underway for drugs, as well as a vaccine, that seek to interrupt the build-up of amyloid in the brain. If they are found to be safe and effective, these would be the first treatments that address what many experts think is the underlying cause of cell death. Unfortunately, it could take years for these therapies to reach patients. In the meantime, the primary goals of therapy for AD are to improve the quality of life and day-to-day functioning.

Current treatments for Alzheimer’s include three relatively new medications that increase brain levels of acetylcholine, a neurotransmitter involved in the learning and memory processes. These drugs – Aricept, Exelon and Reminyl – have been modestly successful in some patients for improving memory and attention skills, and they may also have a beneficial effect on behavioural symptoms such as aggression.

Treatments may also target behavioural symptoms associated with AD, such as agitation, delusions, hallucinations, depression, or sleep difficulties. Medications to control these problems might include anti-depressants (such as Prozac, Zoloft and others), or sleep aids (such as zopiclone). Consistent medical and psychological therapy is important for the individual as well as for family members.

When severe memory loss significantly interferes with daily life, simple tasks can be difficult or insurmountable. Below are some strategies recommended by experts that may help lessen the impact on day-to-day functioning.

The material on this page “Disorders - Alzheimer's” has been sourced from the Dana Alliance for Brain Initiatives. www.dana.org/stayingsharp