Elsevier

Psychiatry

Volume 6, Issue 12, December 2007, Pages 491-497
Psychiatry

Assessment of Dementia
Clinical assessment in dementia

https://doi.org/10.1016/j.mppsy.2007.09.007Get rights and content

Abstract

In the past, symptoms of dementia were easily dismissed as ‘just old age’, but with the availability of treatment for some forms of dementia, an accurate diagnosis is more important than ever. Dementia, however, can be difficult to diagnose, where only through a thorough assessment can it be determined whether the patient has dementia and whether their symptoms conform to a particular pattern. We have set out the structure of a comprehensive clinical assessment of someone suspected of having dementia. When assessing a patient with cognitive impairment it must always be considered that the patient may have delirium or depression. The most vital part of the assessment is history-taking, from both the patient and also from a close informant as, depending on the degree of cognitive impairment present, the amount and accuracy of information given by the patient will vary. It is important to explore all the details of the difficulties the patient is having and identify which cognitive domains may be impaired to have caused them. The clinician must also have an array of bedside cognitive tests to support his or her suspicions of cognitive impairment from the history taken. Investigations, including blood tests and radiology, are used to exclude comorbid physical illnesses which may be partially, or rarely completely, reversible for the cognitive symptoms. A good clinician is aware of the limitations of the investigations and knows when it is appropriate to use them.

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:

  • 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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