dementia

What is Dementia?
Dementia is a brain condition characterized by progressive intellectual impairment. The word is derived from Latin; de "from", and mens "mind" or "brain". Thus, it refers literally to a condition from the mind or brain. Dementia is typically a problem of later adulthood and old age, although it occurs in younger adults as well. A slow, steady and progressive impairment of brain functioning in older adults is called a degenerative dementia and the most common form is Alzheimer's disease. Causes of Dementia in younger adults include traumatic brain injury, strokes, AIDS, and brain tumours.

Delirium is another form of global impairment of intellectual functioning. This condition differs from dementia in that consciousness is prominently disturbed whereas in dementia it is normal. Delirium also has an abrupt onset, is caused by a physical illness (such as bladder infection), and usually resolves completely after treatment. By contrast, dementia in older adults is slowly progressive (brain failure) and leads to death.

Cognitive or intellectual functions are our "brain power" and consist of memory, sensory processing, motor control, planning and organisation, attention and concentration, and speech. Dementia affects mainly cognitive functions, but as the disease progresses it affects all aspects of brain functioning.

In older adults, Alzheimer's disease, is the cause for dementia in approximately 60% of cases. Second most common is Vascular Dementia (VaD) in 13% of cases. VaD is also known as "hardening" of the arteries and is associated with poor blood supply to the brain. It occurs most commonly in association with strokes, hypertension, diabetes, and high cholesterol. Depression accounts for about 4% of cases with dementia.

There are dozens of conditions that can cause or mimic dementia. These include depression, anxiety, anaemia, and infections such as syphilis and AIDS, vitamin deficiencies, and hypothyroidism. Many of these are reversible, so it is always important to obtain a proper diagnosis and initiate treatment as early as possible.

Dementia or normal memory?
Doctors are often asked the question: Is my memory normal for my age? Loss of neurons (brain cells) may be a part of the normal ageing process. As we grow older we may lose certain intellectual abilities and we then become concerned that Alzheimer's disease may be developing. Ageing is accompanied by a richness of human experience and this makes older adults much wiser. This wisdom in old age compensates adequately for an apparent loss of brainpower. Elderly people may be losing brain cells, but they are certainly capable of forming rich interconnections between brain cells. Stimulation and interaction with the environment creates this richness of experience, which translates into the formation of new interconnections. It is difficult to distinguish impaired memory from age related memory difficulties without the assistance of a memory test. Memory tests, also known as cognitive tests, are the easiest and most reliable methods for assessment of impaired memory and intellectual abilities.

It is sometimes astounding to see how family unwittingly cope with cognitive impairment in a loved one. A person may not remember the date, and a spouse or family member will unconsciously avoid asking about it. A patient may forget how to use the kettle or stove and again a family member will unconsciously take over these tasks. Unknowingly, family members compensate and it is thus, only on objective memory testing, that the full extent of the problem becomes evident.

Friends and family members will deny the presence of a significant memory problem, because they say a patient can remember events from long ago. However, this is long-term memory and is only affected in the advanced stages of dementia. It is the memory engine, forming new memory, which is affected in the early stages of Alzheimer's disease. The memory engine for new memory is situated in the medial temporal lobes of the brain. This engine creates short-term memory and helps one to function on a day-to-day basis. It helps one remember scheduled appointments for the day or week and enables one not to tell the same story repeatedly.

A number of memory tests or cognitive assessments are available. The Mini Mental Status Examination is a clinical test that is widely used.

Another important tool to distinguish normal memory from age related memory difficulties, is to measure functioning in daily activities. An older adult should still be able to function in many complex activities. The person should be able to manage his own finances, make appointments, socialise in a way that is rewarding, and pursue hobbies. Deterioration in functioning on these activities of daily living, may indicate dementia.

Information provided by Dr. Frans Hugo, neuropsychiatrist at the Panorama Memory Clinic. Tel: (021) 930-2177, Web: http://www.gomemory.co.za