Alzheimer's disease

Alzheimer's disease is the most common form of dementia, a condition in which normal brain function is lost.

Symptoms

Alzheimer’s disease causes progressive problems with memory, thinking and behaviour. In most cases Alzheimer's disease has a gradual onset. At first there may be little more than the forgetfulness that most of us experience from time to time.

Some examples of Alzheimer’s disease symptoms include:

  • mild confusion;
  • difficulty finding the words for everyday objects;
  • vagueness and difficulty taking part in conversations;
  • difficulty making decisions;
  • taking longer to perform tasks;
  • loss of social skills;
  • frequently misplacing objects, sometimes putting them in strange places; and
  • repeating statements and questions over and over.

As the disease progresses there may be a very obvious loss of memory for recent events, inability to perform familiar tasks (such as reading and writing) or learn new tasks, and confusion about the time and date. Personality changes, aggression, loss of inhibitions and mood swings can also occur.

In the more advanced stages of Alzheimer's there is a loss of the ability to recognise close relatives and perform simple tasks such as washing, eating and getting dressed. In the late stages, brain changes may affect physical functions including swallowing, balance and bladder and bowel control.

Symptoms can vary from day to day, and often become worse when the person is tired, stressed or unwell.

The rate of progression of Alzheimer’s disease will vary from person to person, but affected people do eventually become completely dependent on others. Life expectancy also varies from person to person, with the average being 7 to 10 years.

Causes

There are 2 types of Alzheimer’s disease: sporadic and familial. In both types, the brain cells and the connections between them become damaged, and eventually the brain cells die.

Sporadic

Most cases of Alzheimer’s disease are sporadic, and are caused by a combination of genetic, environmental and lifestyle factors. Sporadic Alzheimer’s usually affects people older than 65 years of age.

Familial

Fortunately, this inherited form of Alzheimer’s disease, which usually affects people aged in their 40s or 50s, accounts for less than 5 per cent of cases. People with this form of the disease have a 50 per cent chance of passing the disease on to each of their children.

Risk factors

There are several factors that can increase your risk of developing Alzheimer’s disease, including:

  • increasing age;
  • family history of Alzheimer’s disease;
  • history of head trauma; and
  • a range of risk factors that affect heart and brain health, such as obesity, high blood pressure, high cholesterol, diabetes, smoking and lack of exercise.

Protective factors

Studies have found that certain lifestyle factors may help reduce your risk of developing Alzheimer’s disease. These factors include:

Diagnosis

Doctors are nearly always able to diagnose dementia, but cannot always determine the cause of dementia. At present, there are no tests that can give definite confirmation that Alzheimer’s disease is present.

There are known brain changes that occur with Alzheimer’s disease – brain shrinkage, and 2 types of abnormalities seen in Alzheimer’s brain tissue called plaques and tangles. Unfortunately these changes can only been seen by examining brain tissue under a microscope after the person has died.

A number of conditions, many of them treatable, can produce symptoms that might make one suspect Alzheimer's. These conditions include hormone disorders, nutritional deficiency, strokes, depression and head injuries. For this reason, it is very important that anyone whose memory or other brain functions seem to be deteriorating has a thorough medical assessment.

Scans and X-rays

Brain imaging, such as CT scans, magnetic resonance imaging (MRI), and positron emission tomography (PET) scans, is currently used to rule out other causes of dementia symptoms. However, in the future, such tests may be used to detect changes consistent with Alzheimer’s disease, such as brain shrinkage.

Treatment

Unfortunately, there is currently no cure for Alzheimer’s disease. However, there are treatments available that can help improve symptoms and maximise functioning.

Medicines

Medicines used to treat Alzheimer’s disease include the following.

  • Cholinesterase inhibitors, such as donepezil (brand name Aricept), galantamine (brand name Reminyl) and rivastigmine (brand name Exelon), which can help prevent symptom progression for a time, and (in some people) temporarily improve cognitive functioning in people with mild to moderate Alzheimer’s disease. Unfortunately, side effects associated with cholinesterase inhibitors, particularly their prominent gastrointestinal side effects (including nausea and vomiting) can prevent their use in some people.
  • Memantine (brand name Ebixa), which can be used to treat people with moderately-severe to severe Alzheimer’s disease.

There are also medicines available to help treat some of the symptoms that can accompany dementia, such as agitation, depression, anxiety and insomnia.

Management of behavioural symptoms

Making adjustments and improvements to the living environment of someone with dementia is an important aspect of managing symptoms. An appropriately stimulating, familiar living space can help prevent certain problems such as agitation.

There is a Dementia Behaviour Management Advisory Service (with a 24-hour helpline) in all Australian states and territories. This service can provide advice and information on challenging behaviours in people with dementia.

Lifestyle

Eating a healthy diet and getting regular exercise not only helps keep your body healthy, but may also help maintain cognitive health. Regular exercise such as walking can also improve mood, help maintain mobility, promote restful sleep and prevent problems such as constipation.

Participating in social activities and activities that involve intellectual stimulation may also help slow mental decline.

Complementary therapies

Some complementary treatments for Alzheimer’s disease have been studied, including vitamin E, gingko biloba, and omega-3 fatty acids in fish oil. The safety and efficacy of these and other complementary therapies is still unclear. Talk to your doctor before taking any complementary or herbal medicines.

Support

People with Alzheimer’s disease, their families and carers need support in managing dementia. Education about Alzheimer’s disease and support – both from health care workers and support groups – are very important parts of the overall management of this condition.

Last Reviewed: 9 August 2013
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References

1. Dementia (revised June 2013). In: eTG complete. Melbourne: Therapeutic Guidelines Limited; 2013 Jul. http://online.tg.org.au/complete/ (accessed Jul 2013).
2. Alzheimer’s Australia. Alzheimer’s disease (updated 18 June 2012). http://www.fightdementia.org.au/content/alzheimers-disease (accessed Jun 2013).
3. Alzheimer’s Australia. Help sheet: What is Alzheimer’s disease? (updated March 2012). http://www.fightdementia.org.au/sites/default/files/pdf/Help_Sheet_Alzheimers_Disease.pdf (accessed Jun 2013).
4. MayoClinic.com. Alzheimer’s disease (updated 19 Jan 2013). http://www.mayoclinic.com/health/alzheimers-disease/DS00161 (accessed Jun 2013).
5. Brain Foundation. Alzheimer’s disease. http://brainfoundation.org.au/medical-info/7-alzheimers-disease (accessed Jun 2013).
6. National Institute on Ageing. Alzheimer’s disease fact sheet (updated 21 May 2013). http://www.nia.nih.gov/alzheimers/publication/alzheimers-disease-fact-sheet (accessed Jun 2013)
7. Alzheimer’s Australia. Drug treatments and dementia. http://www.fightdementia.org.au/understanding-dementia/drug-treatments-and-dementia.aspx (accessed Jul 2013).
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