Imagine gradually forgetting names, numbers, people and a gradual erosion of your personality. This is Alzheimer's, and it affects 417,000 people in the UK alone (1). As we live longer, the proportion of people affected by this condition will increase and unfortunately, there is no cure. Alzheimer's has a profound effect not only on the sufferer, but their carers and society at large. This article will discuss what Alzheimer's is, how it is diagnosed and how it is treated.
What is Alzheimer's?
Alzheimer's is the leading cause of dementia in the world. Dementia is a condition where key elements of how we think and behave are affected. Common symptoms include:
Alzheimer's is a disease in which a cascade of chemical changes in the brain eventually results in damage to neurons (nerve cells that transmit information in the brain and nervous system), resulting in failure of communication between neurons. This progressive failure results in the gradual erosion of our cognitive abilities. The cause of this neuron damage is thought to be partly due to the production of toxic proteins (called beta amyloid) in the brain; however, this may only be one of the mechanisms. Further research into the causes of this complex condition continues.
Are you at risk?
Age: The main risk factor for development of Alzheimer's dementia is age. After the age of 65, the proportion of people with this disease doubles every 5 years (2). Over the age of 90, almost a fifth of people have Alzheimer's dementia. Alzheimer's, however, is not actually exclusive to the elderly. It is estimated that approximately 15,000 people in the UK under the age of 65 already suffer from this disease as well. Below are some of the risk factors.
Genetics: This is an area of increasing research. It is clear that in a minority of cases, especially those who develop Alzheimer's under the age of 65, there is a strong argument that Alzheimer's may be inherited. Research has shown that people carrying the APP, PSEN1 and PSEN2 genes are more likely to develop early onset Alzheimer's. However, it is rare to have one of these genes.. People with the ApoE4 gene seem to have a much higher risk of going onto develop late onset Alzheimer's. In most cases though, inheritance is unlikely to be play a significant factor. If a member of your family has been diagnosed with dementia, the responsible specialist will identify those cases in which genetic counselling is relevant. This is rarely necessary but it's a good question to ask if you are concerned.
Down's Syndrome: People with Down's syndrome are more likely to develop Alzheimer's. This is thought to be due to the underlying chromosomal abnormality.
Lifestyle: Factors such as smoking, high cholesterol and high blood pressure are all thought to increase the risk of developing Alzheimer's. Diet is also important. Evidence suggests that eating a balanced and varied diet may be protective.
Aluminium: There has been much media hype about the possible relationship between aluminium and Alzheimer's. There is currently no reliable evidence demonstrates a causal relationship.
I'm worried about my memory.
We all have times when we forget things. If, however, you are noticing problems coping with day-to-day activities due to your memory problems, or if family members have concerns about your memory, then it is important to discuss this with your doctor. Remember, Alzheimer's is a gradual onset condition. Catching it early is important, as treatment can delay progression.
Diagnosis
Diagnosing Alzheimer's is complex. There are no simple blood tests. The diagnostic process involves excluding other causes of dementia, blood test abnormalities and other medical problems, which may mimic dementia. The first steps involve your doctor taking a detailed history and carrying out an examination. This examination is likely to include a test called a mini mental state exam (MMSE). This is used as a screening tool and can also help assess the severity of dementia. Short and long term memory, concentration, orientation and other key cognitive faculties are then assessed and scored. The score can also indicate the severity of dementia.
Blood tests are carried out to look for reversible causes of cognitive impairment, such as an under active thyroid, raised calcium levels or a deficiency of vitamin B12 and folic acid. If blood tests are normal and there are still concerns, you will probably be referred to a specialist.
The diagnosis of Alzheimer's is rarely made in general practice due to the complex criteria and the need for more advanced investigations. The diagnosis often requires a team of specialists working together in dedicated memory clinics.
Memory Clinics
Your location, along with your age and other factors, will determine the type of specialist who will be in charge of your care if you live in the UK. Alzheimer's is managed by several different specialties including psychiatry, neurology and care of the elderly. The specialists will often work as part of a multidisciplinary team. The clinics pool together medical, occupational therapy and psychology specialists who work together to assess and treat patients with Alzheimer's.
In most cases blood tests would have been arranged by the GP. Further tests such as more sophisticated cognitive testing and brain imaging are usually carried out in memory clinics.
Brain imaging is usually done using CT scanners. The brain scan helps to exclude other causes of cognitive impairment such as chronic bleeds, hydrocephalus (excessive fluid around the brain) and tumours. Brain imaging may help to differentiate between Alzheimer's and other causes of dementia.
The diagnostic process can seem daunting, but it is necessary. After all, early diagnosis can help provide greater insight into one's condition and help you take a more active role with regards to treatment. Early intervention can help delay the progress of Alzheimer's.
Treatments
The current mainstay of medical treatment involves drugs classified as acetylcholinesterase inhibitors. These drugs help maintain communication between neurons in the brain by helping to maintain levels of a neurotransmitter called acetylcholine (a chemical that helps transmit signals from one neuron to another). This delays the progress of Alzheimer's dementia, but it cannot offer a cure. The drugs found in this group are:
There is another drug available called Memantine (Ebixa®). It works by improving neuron communication using a different neurotransmitter system in the brain.
These drugs are only licensed for use in mild to moderate dementia. The most commonly prescribed medicine for Alzheimer's dementia in the UK is Donepezil®. It is only taken once a day and comes in two doses; this makes taking the medication much easier for patients and their carers. Treatment is usually reviewed at 3-4 months to see whether there has been an improvement or not. This is assessed using serial MMSE tests. If the MMSE falls below 12, then treatment is usually stopped. An important drawback with these medications is that they lose their effectiveness gradually over time.
As well as the above medications, doctors will usually try and avoid adding additional medications that may promote confusion and worsening of symptoms. Opiate-based pain killers are a good example of this.
Drugs Used in Severe Alzheimer's
As discussed, most of the above medications can only be used in mild to moderate Alzheimer's. In severe dementia, symptoms such as agitation, aggressiveness and hallucination may become more prominent. These worrying symptoms do not occur in everyone. Examples of medications used to treat the symptoms of severe Alzheimer's include:
Non-medical treatments
Just as important as drug therapy are non-medical treatments. Patients are encouraged to engage in some form of regular exercise. This can help the patient maintain their ability to carry out daily activities, such as dressing, bathing and using the toilet. Diet is also crucial. Ensuring a varied diet helps maintain levels of essential micro nutrients like vitamin B12 and folic acid, which are both crucial in cognitive function. Patients will also be advised to avoid alcohol, as this can worsen confusion. As symptoms progress, physiotherapists and occupational therapists are key in providing suitable adaptations for patients in their home environments. This allows the sufferer some degree of independence and while maintaining their safety.
A Final Thought
As scientists and doctors learn more about Alzheimer's and unravel the biology of ageing, we will hopefully see developments in the ability to pick up mild cognitive impairment, which can precede the diagnosis of Alzheimer's by several years. Research from the US has suggested that potential intervention during this stage could reduce the need for future nursing home care. It may also reduce the risk of misdiagnosis and inappropriate management. Unlocking the causes of Alzheimer's should also see the development of more effective treatments. At present, early diagnosis and referral to memory clinics is the cornerstone of effective management.
Further information
Please visit the following websites for information and support for patients and carers.
Alzheimer's Society: Staff and volunteers provide help and information for sufferers of dementia. The online website provides a variety of downloadable fact sheets.
Carers.org: The Princess Royal Trust for Carers is the largest provider of comprehensive care services for those of us looking after people with terminal illnesses and chronic disease.
Sources
1) Querfurth, H.W. LaFerla, F.M. Mechanisms of disease: Alzheimer's Disease. The New England Journal of Medicine, 362(4), 2010, pp. 329-344.
2) National Collaborating Centre for Mental Health. Dementia A NICE–SCIE Guideline on supporting people with dementia and their carers in health and social care. The British Psychological Society and Gaskell, Number 42, 2007.
