Alzheimer’s disease

Alzheimer's disease is the most common form of dementia and a leading cause of death in the developed world.

Known commonly as “Alzheimer’s”, this incurable brain disease was named after the physician Alois Alzheimer, who identified it in 1907.

Itis marked by a progressive degeneration of brain tissue, and primarily affects elderly people. Eventually,sufferers lose the ability to think and co-ordinate movement. The illness usually runs its course in six to eight years, but may be more rapid(a few months), or up to 20 years.

Who gets Alzheimer’s?

It mainly occurs in people aged 65+; this is called late-onset Alzheimer’s. From age 60, risk for Alzheimer’s or a related dementia doubles every five years.

Much more rarely, early-onset Alzheimer’s occurs among people in their 50s, 40s and even 30s.

Nearly all people with Down syndrome who reach their 40s develop Alzheimer’s.

Other risk factors include family history of dementia and previous head injury.

Alzheimer’s?

The causes are not fully understood and research is ongoing. Microscopic study of the brains of people who died from Alzheimer’s reveals characteristic abnormalities: tangled nerve cell fibres, and protein deposits called plaques that build up in the affected tissue. It’s not clear whether these tangles and plaques are a causeor result of the disease, but it is suspectedthey interfere with transmission of neural messaging in the brain.

There are likely also genetic factors involved.The association between Down syndrome and Alzheimer's led scientists to look for genetic factors on chromosome 21, the chromosome involved in Down syndrome. Scientists have also discovered a gene on chromosome 19 that is a marker for heart disease commonly found in Alzheimer’s patients. Scientists think people with this gene might be more susceptible to Alzheimer's.

Other research found increased levels of certain metals in the brains of Alzheimer’s patients. This led to a controversial theory that ingestion of small particles of these metals, especially aluminium,may cause Alzheimer's. More research is necessary to determine whether aluminium build-up is a cause or result of Alzheimer’s and to better understand itsrole in development of the disorder.Other studies showed that zinc could make proteins form clumps similar to Alzheimer’s plaques.

of Alzheimer’s

Symptoms vary among patients, but some general symptoms can be distinguished:

Early stage. Usually the first two to four years. Symptoms are gradual and often mistaken for  normal ageing. Early signs of memory loss include forgetting names or events, difficulty following directions, disorientation. There may be changes in normal behaviour and personality, and trouble performing routine tasks.

Later stage.There may besudden loss of inhibitions, inability to solve simple problems and trouble with figures. Adapting to simple changes becomes problematic; there may be confusion and disorientation e.g. not knowing the month or year, being unable to describe where they live or recall a recently visited place-name.

Sufferers become increasingly suspicious and paranoid. They can’t control anger, frustration or inappropriate behaviour and become irritable and agitated. They can’t dress appropriately and neglect their personal appearance.

Final stage.Severe impairment of intellectual abilities. Physical functioning deteriorates e.g. incontinence (inability to control bowel and bladder function). They can’t engage in conversation, are erratic, inattentive andunco-operative. Eventually they become incapable of looking after themselves, and are often bedridden or wheelchair-bound. Death is usually from pneumonia or another illness that occurs when health has deteriorated severely.

Consult your doctor if a family member or friend displays signs of Alzheimer’s over time. The person maylack of insight thathe or she has the disease and may need persuasion to get medical help.

Medical diagnosis is important, as several other treatable conditions (e.g. hypothyroidism, vitamin deficiency, hypoglycaemia, anaemia, depression, adverse reaction to medications) have symptoms similar to Alzheimer's.

The doctor does a memory test, then a physical examination to eliminate other possible causes of the mental impairment. Verbal tests and interviews with family members may follow.

Other diagnostic tests could include blood tests, brain scans, electrocardiogram (ECG, recording of the heart’s electrical activity) and electroencephalogram (EEG, recording of the brain’s electrical activity).

There is no cure for Alzheimer's. Certain medicines can improve memory and slowearly-stage disease progression; others can alleviate associated mood changes and behavioural problems.

Home care

The patient’s home environment can play an important role incoping with the disease. Family members and care takers can modify the surroundings positively as follows:

• Provide balanced nutrition and plenty of fluids.
• Keep pills and poisons away.
• Keep instructions simple and short.
• Promote a feeling of safety. Keep the environment familiar and stable; stick to routines.
• Keep visual clues to time and place, such as calendars and clocks.
• Leave reminder notes and simple directions.
• Label objects.
• An ID bracelet with a phone number is indispensable, asAlzheimer's patients may wander and get lost.
• As long-term memory is better than short-term in the early stages, the person may enjoy reminiscing. Use photo albums, old magazines and family stories to bring pleasant memories to the fore.

Looking after an Alzheimer's patient isemotionally draining, and it’s important for care takers to seek help from support groups, social workers and mental health professionals.

Can Alzheimer’s be prevented?

Prevention is difficult, as there is no known cause. The best defence is to follow a healthy lifestyle:

• Eat a balanced diet
• Get regular exercise.
• Stay mentally active.
• Avoid cigarette smoke and air pollution.
• Omega-3 fatty acids may have a preventative role.
• Don’t overdo intake of zinc, but less than the recommended daily allowance (15 mg for men; 12 mg for women) does more harm than good.
• Social interaction may be protective.
• Alcohol, particularly in excess, has been identified as neurotoxic.

Reviewed by Dr Michael S. Mason, MB ChB, FC Psych (South Africa), Consultant Psychiatrist in Private Practice at Panorama Psychiatry and Memory Clinic, for Health24, September 2011