Dementia is a set of symptoms which includes loss of memory, understanding and judgement. People used to call dementia ‘senility’. There are many causes of dementia, and the most common one is Alzheimer Disease.

Alzheimer Disease

Alzheimer's Disease is a progressive, degenerative, and irreversible disease.

Alzheimer's Disease causes gradual breakdown in the nerve cells of the brain. The brain changes and no longer works the way it used to. As a result, people with Alzheimer's Disease become less and less able to make sense of information from the outside world and to send messages to their bodies. People with Alzheimer's Disease become unable to think, remember, understand, and make decisions as before. They will have trouble with everyday activities such as getting dressed, cooking a meal, or washing the car. Eventually, they become unable to look after themselves and will develop other illnesses such as pneumonia, which will cause death.

Alzheimer's Disease was discovered in 1906 by the German neurologist, Alois Alzheimer. He published a paper describing the case of a 55 year-old woman with dementia. In the article Alzheimer described the plaques and tangles in the brain which have become the markers for Alzheimer Disease.

The Facts

• Alzheimer's Disease is not a normal part of aging.
• The majority of people with Alzheimer's Disease are over the age of 65, though individuals have been diagnosed as young as 30.
• Alzheimer's Disease knows no boundaries, it affects men and women of all races, religions and socio-economic backgrounds.
• To date, the cause of Alzheimer's Disease is not known.

Symptoms                                              Statistics

Vascular Dementia

Vascular dementia is dementia associated with problems in the circulation of blood to the brain. Vascular dementia is often caused by strokes. A stroke occurs when blood vessels in the brain burst, if arteries become blocked by plaque formation or clots, or if there is insufficient blood flow to the brain, and the result is that brain tissue will die.

Vascular dementia is common in people between age 60 and 75, and is slightly more common in men than in women. The risk factors for vascular dementia are the same as those associated with stroke (i.e. high blood pressure, diabetes, high cholesterol, history of TIA’s).

Frontal Lobe Dementia and Pick’s Disease

Less than 10 per cent of all dementias are frontal lobe dementia. Frontal lobe dementia can be distinguished from Alzheimer Disease early in the course of the illness. Frontal lobe dementia affects the temporal lobes, frontal lobe, or both temporal and frontal lobes.

Damage to the frontal lobe leads to alterations in personality and behaviour, changes in the way a person feels and expresses emotion, and loss of judgement. The first symptoms of frontal lobe dementia are typically psychological and behavioural problems. These may include changes in character and in social behaviour. The person may show insensitivity or lack of constraint, which may result in the person getting in trouble with the criminal justice system because of stealing or behaviour that lands them in trouble. The person may become quite obsessive during the early stages. For example everything must be neat and in order or the person may repeatedly wash their hands. As well, there may be sexual misadventures, social graces may deteriorate, and the person may make inappropriate comments.

As well as personality and behavioural problems the person will experience language problems. For example, they may have limited speech output, lack of speech spontaneity, decreased vocabulary, and repetition. The person may use jargon, meaning that instead of being able to find the word to describe an object, the person with the disease will give a description of it instead.

Pick's Disease

Pick's Disease is a type of frontal lobe/temporal dementia. The onset is typically in the mid to late 50’s, and life expectancy is approximately 2-15 years with an average of 6-12 years. The cause of Picks Disease is unknown, however there may be a genetic component as 50 per cent of Pick’s patients can be found to have a first-degree relative with the disease.

Kluver Bucy Syndrome is a group of problems relatively common in Picks Disease. The symptoms include hyper sexuality, gluttony, and an obsession to touch and seize any objects in the field of vision.

The difference between Pick’s Disease and Alzheimer's Disease is that the damage occurs in different areas of the brain in the early stages. In Picks Disease impairment of intellect and memory occur later than in Alzheimer Disease. In the late stages of Picks Disease Parkinsonian symptoms, immobility, incontinence, and mutism can occur. In the terminal stage the different dementias are clinically undistinguishable.

Lewy Body Dementia

Lewy Body Dementia is a type of dementia whose features overlap those of Alzheimer Disease, and Parkinson’s Disease. There is often a fluctuation in the severity of the condition on a day-to-day basis, and there is often an early development of hallucinations. Lewy Body Dementia lasts an average of seven years. The risk factors for Lewy Body Disease have not been identified.

Many people with Lewy Body Dementia initially complain of impaired recent memory, for other people the main problem is behavioural disturbances with preserved memory. There may be fluctuations in cognitive performance during the early stages of the disease. There is a presence of visual hallucinations, which are not always disturbing to the patients. There is also a presence of clinical features of Parkinson’s Disease, such as a flexed posture, shifting gait, reduced arm swing, or a tendency to fall.

Parkinson’s Disease

Parkinson’s Disease is a motor system disorder, it is a chronic and progressive disease. It generally targets older adults, with approximately 15 per cent below the age of 50. The four primary symptoms are:

• tremor or trembling in hands, arms, legs, jaw and face;
• rigidity or stiffness of the limbs and trunk;
• bradykinesia or slowness of movement; and
• postural instability or impaired balance and coordination.

Treatment of Parkinson’s Disease is aimed at treating the symptoms.

Thirty per cent of Parkinson’s patients will develop dementia. In 75 per cent of these cases changes in the brain resemble Alzheimer's Disease, and in the remainder changes are distinct and called dementia with Lewy Bodies.

Cortical dementia is a type of dementia that can occur in people with Parkinson’s Disease. Compared to Alzheimer's Disease people are more anxious, easily agitated, and generally more irritable. As well, they may develop delusions or thinking patterns that are not rational.

Alzheimer's Disease and Down Syndrome

Down Syndrome is a genetic disorder where people have an extra chromosome 21. This causes delays and limitations in physical and intellectual development. People with Down Syndrome appear to age more rapidly than other persons in the general population and are thus at greater risk of Alzheimer's Disease than are peers of a similar age. Many individuals with Down Syndrome who live past 35 develop the characteristic markers for Alzheimer's Disease (plaque/tangles in the brain). Those people with a developmental disability are at a greater risk for Alzheimer's Disease if the individual is over 40 and if the individual has a history of Alzheimer's Disease in their family.