Alzheimer's disease is just one form of dementia that can affect older people.
It is the most common form, but vascular dementia can co-exist. It is a progressive, degenerative disease of the brain causing problems with memory and functioning. Other forms of dementia are Creutzfeldt-Jakob disease and Lewy body dementia.
The two hallmarks of the disease are described as 'plaques' and 'tangles'.
Plaques are numerous tiny dense deposits scattered throughout the brain that become toxic to brain cells at excessive levels. These 'tangles' of fibrils can be found within brain cells and interfere with vital processes.
When brain cells degenerate and die, the brain markedly shrinks in some regions and this can be seen as cerebral atrophy on CT or MRI brain scanning.
Taking a good patient history is the best way to establish a diagnosis. The key point is memory impairment, which is characteristically a late onset of short-term memory loss while memories of events that happened years ago are preserved.
Impairment of social functioning can also occur and this will include apathy, withdrawal from social situations and changes in personality.
Difficulties will be encountered in day-to-day activities such as shopping, using money or using the telephone. If the patient is still working, colleagues will have noticed a change in their personality and functioning. It is useful to ask relatives about warning signs (see box). Also ask about alcohol intake and smoking; excesive alcohol intake can increase signs of mental dysfunction.
The mini-mental state examination (MMSE) is a checklist of mental functioning that can be used to assess the severity of Alzheimer's disease.
The MMSE checklist can be accessed on www.aaa-online.org.uk/Pages/Delerium/Mini-Mental State% 20Exam.htm
A thorough physical examination should be carried out looking for co-morbidities such as hypertension, cardiovascular disease, diabetes and myxoedema. Potential contraindications to cholinesterase inhibitors should be identified, for example COPD, prostatic symptoms, active peptic ulceration and bradycardia.
Laboratory tests that may be carried out to exclude other co-morbidities are FBC including mean cell volume (MCV); U&Es; LFT including gamma-glutamyl transferase; TFT; fasting glucose and lipids; B12 and folate if MCV is high.
Patients with evidence of impairment of functioning, social behaviour or personality in addition to memory difficulties should be referred to local psychiatric services.
Patients with dementia are still entitled to confidentiality and, unless proven otherwise, under the Mental Capacity Act adults are assumed to have the capacity to make decisions about their care and treatment. Information disclosed by relatives should not be given to the patient and vice versa.
NICE guidance restricts treatment to patients with moderate Alzheimer's disease: those who score between 10-20 on the MMSE. The maximum score is 30. These patients can be treated with one of the cholinesterase inhibitors, donepezil, galantamine and rivastigmine.
The MMSE does not take account of function, behaviour or personality and these all need to be considered before deciding the true severity of a person's dementia.
Side-effects of cholinesterase inhibitors include dizziness, nausea, vomiting and urinary dysfunction. Side-effects tend to be mild and transient. Long-term therapy appears to be safe, but some patients develop problematic bradycardia.
There is no real evidence to support alternatives to cholinesterase inhibitors for mild forms of dementia.
Cognitive stimulation and reality orientation show some promise. Treating co-existing vascular dementia with ACE inhibitors, aspirin and statins may help to some extent.
Antipsychotics such as olanzapine and risperidone are sometimes used for the behavioural and psychotic problems of the disease, but they raise the risk of stroke in these patients.
Discussion with relatives will be required, as these agents are very effective and sometimes their use is justified.
Antidepressants can be effective but take longer to have an effect than in patients without cognitive impairment.
Dementia is a clinical domain in the quality framework.
- Dr Warburton is a GP in Ironbridge, Shropshire
- 21 September is World Alzheimer's day. For more information see www.alz.co.uk
Ten warning signs in patient history
- Memory loss that affects day-to-day functioning.
- Difficulty in performing familiar tasks.
- Problems with speech: finding the right word or forgetting words.
- Disorientation in time and place.
- Poor or decreased judgment, for example wearing inappropriate clothing on a hot day.
- Problems with abstract thinking, such as balancing a cheque book, not recognising numbers.
- Misplacing things: the patient may put things in odd places, such as the iron in the freezer.
- Changes in mood and behaviour, such as mood swings from calm to tears in short spaces of time.
- Changes in personality: confusion, suspicion or paranoia.
- Loss of initiative: requiring cues to become involved in social situations or to carry on with tasks such as housework.