Last updated:11-28-2009
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Definition of Dementia - including Alzheimer's disease

Dementia is a disease which affects intelligence, memory, personality and emotional life. Dementia may occur in association with other diseases and will generally disappear when the underlying condition is treated. However, often Dementia is the root, stand alone problem, and it is progressive. 
Dementia evolves over several years, where the patient becomes increasingly forgetful, confused and undergo personality changes. Even simple tasks at home can be difficult to perform, and more and more external care and support becomes necessary.
Dementia affects mostly elderly people. Six percent of people over 65 years and twenty percent of people over 85 years suffer from the disease. However, it is very important to remember that the vast majority of older people are mentally well functioning. Many older people are worried about developing dementia when they forget things, but a slight weakening of short-term memory is quite normal in later years. Although the risk of dementia increases with age the disease might also strike younger persons. This is then called pre-senile dementia and is almost always the type Alzheimer's. The incidence is typically one for every 1.200 persons.

Causes and classifications

There are many causes of dementia. The condition is often separated between reversible where treatment is possible and irreversible.

Reversible causes of dementia:

  • Vitamin deficiencies: This is usually a lack of vitamin B12.
  • Depression in the elderly can give the same symptoms as dementia. Confusion, forgetfulness and emotional fluctuations are examples of this. Depression can be treated, and it is therefore important to distinguish between the two variations.
  • Bleeding under the hard brain membrane (meninges) occurs easily in the elderly by even a minor blow to the head, and may resemble the onset of dementia.
  • Infection: A bladder infection or pneumonia may cause confusion and forgetfulness, especially if the elderly is also dehydrated. Also inflammation of the brain or AIDS may cause dementia.
  • Medicine: Over medication, especially the kind that affects the nervous system, may result in dementia symptoms.
  • Alcohol: Can both provide a state of confusion and lethargy, reminiscent of dementia, but this stops when the intake of alcohol is stopped. It might also cause real dementia (see later).
  • Low blood sugar: This and other metabolic problems, for example myxoedema might create a lethargic state, reminiscent of dementia.
  • Brain Tumor: Again, the symptoms may resemble dementia, but if the tumor can be removed, the state improves in many cases. 
Dementia, where the weakening of memory and intelligence are the main problems, can also be divided into several types. The four most common are:
  • Alzheimer's disease: This disease represents 60-80% of dementia cases and is also the kind seen in younger people. A few cases are hereditary. There are deposits of a particular protein (beta-amyloid), mild reduction in brain size (atrophy) and torsion of nerve fibers. Yet, it is still not entirely clear how these findings are connected with the onset of the disease, and there is still much research in this area.
  • Vascular dementia: This type of dementia caused by many small blood clots in the brain, which often have been too small for the person to notice but eventually, there will be such a big part of the brain that no longer works, that symptoms of dementia arise. The mechanism of, and reasons for, the small lesions are the same as for stroke and TCI.
  • Parkinsonism: Here the main disease is not dementia, but after some years symptoms of dementia in the form of Lewy-body appear in which spherical structures called Lewy bodies develop in the brain.
  • Other forms of dementia: There are many other and rarer forms of dementia, of which the commonest is fronto-temporal dementia. In addition, the Wernicke-Korsakoffs syndrome (caused by alcohol) and Creutzfeldt-Jakob disease (rare infection with symptoms of mad cow disease in humans) are often included in this category. 

Symptoms of dementia

The first symptom of dementia is usually weakened short term memory. We forget what has happened hours or minutes ago, but have no trouble remembering what has happened years ago. This may be the only symptom for a long time, and it is perhaps only the affected themselves, who are aware that something has changed. That lesson may be hard, and there will in the first phase of dementia be much frustration and sadness with some developing depression. Since this can worsen the symptoms of dementia treatment is important at this stage. Later in the progression the patient is no longer aware of the condition which might help the patient but make is all the more difficult for the next of kin.
After some time, the surroundings may notice that the patient is more hotheaded and irritable, has easier to tears or appear absent minded and with loss of initiative. Emotions and personality changes too, and the patient may lose social and sexual inhibitions to great embarrassment and discomfort for the surroundings. This is due to the influence of frontal brain lobe and may be more or less pronounced, depending on the type of dementia.
Fatigue is a dominant symptom, and together with the reduced ability to concentrate may gradually lead to the abandonment of leisure and social life. Even television and books are difficult to handle as the continuation of the content is lost. Finally, the ability to perform even daily routines such as cooking and personal hygiene is lost.
There are many dangers associated with living alone for dementia sufferers. Besides skipping meals and personal hygiene lit candles may be forgotten, the stove might be left switched on, etc. Relatives must be alert and early contact the social services or home care to secure the necessary support.
In the final phase of dementia almost all functions are affected. The speech is incoherent, the patient's movements are clumsy or completely inhibited, and the patients are unable to fend for themselves. Usually the affected ends up in a nursing home in need of care around the clock. However, there are very big differences in how long it takes for the disease to advance to this stage. The time from disease onset to the final stage can last more than a decade.

Diagnosis and precautions

If you suspect that you, or a relative, has dementia, you should consult a doctor. The doctor will perform a test, usually MMSE (mini-mental-state examination). This is a test where the person's mental abilities are tested, and you get a very accurate indication of whether there is something wrong. In addition, a scan of the brain is often made, where the typical changes can be seen. Usually a wide range of blood tests are performed to exclude other conditions that may produce symptoms of dementia (see causes). Persons affected by dementia should not drive.

Treatment of dementia

In vascular dementia, treatment is blood thinners. It is important to find the cause of blood clots. It can for example be a narrow carotid artery or atrial fibrillation.In Alzheimer's disease acetylcholine esterase inhibitors may alleviate symptoms delaying the disease by 6-12 months but the development of the disease cannot be stopped.

If Parkinsonism is present the symptoms are treated with medication, as described in Parkinson's disease. 

The essential treatment will be manual therapy, home care, support and care from relatives in order to reduce the loss of function for the patient and delay the need for nursing home as long as possible.

Prevention of dementia

As mentioned Vascular dementia often stems from small blood clots and can therefore to some extent be prevented in the same manner as other blood clotting disorders.

Perform ample exercise and avoid smoking, fatty diets and obesity which all lead to high blood pressure and risk of thrombosis (see also Arteriosclerosis - prevention). Some studies suggest that this may also reduce the risk of Alzheimer's disease. However, there are hereditary factors involved in particular Alzheimer's, and the risk of dementia cannot be fully eliminated through comprehensive prevention.

Related articles:

ALS - Amyotrophic Lateral Sclerosis
Chorea (including Huntington's Chorea)
Dementia & Alzheimers disease
Neuromuscular diseases
Parkinsons disease (Paralysis agitans)



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