Learn about dementia

About dementia

Dementia is a term used to describe a variety of brain disorders that include symptoms such as loss of memory, confusion and problems with speech and understanding, and changes in mood and behaviour. These symptoms may affect a person's ability to function at work, in social relationships or in day-to-day activities. Sometimes symptoms of dementia can be caused by conditions that may be treatable, such as depression, thyroid disease, infections or drug interactions. If the symptoms are not treatable and progress over time, they may be due to damage to the nerve cells in the brain.

Seven A's of dementia
One way of understanding how dementia affects the brain is to look at the seven A's of dementia. Each A represents damage to a particular part of the brain. Please keep in mind that an individual with dementia is not likely to experience all of the A's.

Anosognosia means loss of ability to realize there is anything wrong. You might not understand why you have a memory problem or that you have a memory problem at all. You are in denial, but you honestly do not realize that there is a problem because the part of the brain that allows you to reason is being damaged.

Agnosia means a loss of recognition of sensory information and includes all of the senses: sight, sound, taste, touch, and smell. You might have difficulty effectively sorting out what you see or hear for example. You might experience difficulty recognizing familiar people in your life. Safety can be compromised if this part of the brain is affected because you might confuse objects and their use.

Aphasia means loss of language, and can include both speech and comprehension. Although speaking abilities remain for some time after the onset of Alzheimer's disease, the ability to understand what other people are saying may become affected earlier in the disease process. This lack of understanding can lead to misunderstandings between you and those around you. You might find yourself withdrawing from social interactions due to insecurities caused by loss of comprehension.

Apraxia is a loss of ability to initiate purposeful movement. As well, individuals with apraxia may also have trouble understanding terms such as back, front, up, down. As a result of these loses, it becomes difficult to do things such as tying shoelaces, doing up buttons and zippers, and any activity involving co-ordination. Loss of patterns of movement will result in the eventual inability to co-ordinate hand and leg movement necessary for specific activities such as driving.

Altered perception is the misinterpretation of sensory information. You might find that behaviours are more problematic in the late afternoon or early evening when light changes.

The other significant perception loss is loss of depth perception -- the ability to see in three dimensions. It becomes more challenging to judge how high, deep, long, wide, near of far things are. For example, if the floor and furniture are the same colour, it may be difficult to judge when one is close enough to a chair to try to sit.

Amnesia means loss of memory. This is a significant loss with dementia because everything we do is dependent on access to a working memory. Initially short-term memory will be lost, but eventually long-term memory will go as well. A person with short-term memory has lost the ability to remember what was just spoken, and this is why you might find yourself asking questions over and over again.

Apathy is when you experience a loss of drive or initiative. The part of the brain that controls initiation of activity or communication is damaged. You might find that you have difficulty initiating activities and that you are relying on someone else's cues to keep you involved in a conversation or a task.

Many thanks to Susie Gregg, Education Coordinator, Alzheimer Society of Guelph-Wellington, for permission to reprint her article.