Assessment of DementiaClinical assessment in dementia
Section snippets
Aims of assessment
Dementia is a significant cause of morbidity and mortality in elderly people, with an impact on the health of the population similar to that of lung cancer and stroke.1 With the availability of treatments for some forms of dementia, an accurate diagnosis is more important than ever. Diagnosis also offers patients and caregivers an explanation for the patient’s difficulties and behaviours. Clinical assessment, which needs to be multidisciplinary, should not only determine whether the person has
Differential diagnosis
During the assessment other conditions that can mimic dementia need to be considered: the two main ones are delirium and depression. A comparison of the features of dementia, delirium and depression to aid diagnosis is shown in Table 1.
Delirium is defined as a transient organic mental syndrome of acute onset associated with a physical cause. It is characterized by marked abnormalities of attention, as well as:
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impairments in global cognitive function (e.g. disorientation, reduced attention,
Background information
As the patient to be assessed may have cognitive impairment and may not be able to give a detailed account of their situation and history, it is important to collect as much information as possible before seeing them. It is particularly useful to gain from the referrer (usually the GP) information of the current drug treatment and other medical details.
Assessment may take place in several different settings, each with benefits and disadvantages. It is essential to ensure that the patient is
History
The importance of a detailed history in determining whether a dementia is present cannot be overemphasized. Depending on the degree of cognitive impairment, the amount and accuracy of the information given by the patient will vary. Even if the patient appears to have reasonable insight into their difficulties, it is vital to obtain a collateral history from a source that has regular contact with the patient (e.g. a healthcare professional, carer or family member). It is important to ask the
Mental state examination
It is important to note the patient’s appearance and behaviour. Evidence of self-neglect, inappropriate clothing or poor personal hygiene may indicate depression or dementia. Disinhibition – a symptom of frontal lobe impairment – may be demonstrated by the patient greeting you with a kiss or being over-familiar during the interview. Marked agitation and retardation can be found in dementia but may also indicate depression. Guarded or hostile behaviour may indicate underlying paranoid ideas.
Examination of cognitive state
The information gained in the assessment may indicate in which areas the patient may be impaired. A bedside cognitive assessment can highlight these deficits as well as demonstrating impairments that were not apparent during the history. It is important to test a wide range of functions. Table 4 shows examples of areas to be assessed and tests that can be used.
Physical examination
A physical examination should be performed, with particular reference to finding signs that may suggest the aetiology of an underlying dementia. Observation of Parkinsonian signs, such as shuffling gait, expressionless face and resting tremor in the upper limbs, may indicate DLB and should prompt a full neurological examination. Patients in the early disease stage of DLB have an increased number of primitive reflexes compared with patients with mild AD or Parkinson’s disease.9 The presence of
Investigations
Many investigations can add important information to the assessment (Table 5). The choice of which investigations are conducted is determined by the clinician’s personal preference, local availability and the specific details of the patient concerned. Cost and burden on the patient are also considerations.
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