iv. Screening and assessment for dementia

Aims

The aims of this content focus area are to:

• Present an overview of the screening and assessment processes required for dementia.
• Facilitate understanding of the importance of an inter-disciplinary approach to screening and assessment of a person with a cognitive impairment.

Outcomes

By the end of this content focus area, participants will be able to:

• Explain common diagnostic tools used when a person is suspected of having dementia.
• Outline common scales used to test cognitive function.

Screening and assessment for dementia

The screening and assessment of dementia is complex and, as such, is often most effective when:

• An inter-disciplinary approach guides the use and interpretation of assessment results—involving input from, for example, neuro-psychologists, geriatricians, social workers, nurses and occupational therapists.
• A range of techniques and measures are used.

Information that is commonly collected as part of an assessment includes:

• Personal history (e.g., using self-report questionnaires and standardised interviews).
• Physical health status (e.g., using both a physical examination and laboratory tests which may identify causes of cognitive decline other than dementia).
• Cognitive, social, emotional, and language functioning (e.g., using standardised tests and behavioural observation) (Alzheimer's Australia, 2006).

Physical health status:
In addition to a general physical examination, a number of radiological tests may be used in the screening and assessment of dementia. These include standard X-rays and brain imaging techniques such as Computed Tomography (CT or CAT) scans, Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET) and Single-Photon Emission Computerised Tomography (SPECT) (Alzheimer's Australia, 2006).

Cognitive and related functioning:
Tools/tests that measure different aspects of cognitive and related functioning may also be used as part of screening and assessment for dementia. Several of these are discussed below. (You may find it useful to investigate these and other tests in more detail depending on your scope of practice and professional focus).

A tool that is often used to screen for cognitive impairment is the Mini-Mental State Examination (MMSE). The MMSE is well known across health disciplines having been used for many years. As such, there is considerable evidence supporting both the validity and reliability of this tool. However, its diagnostic usefulness relative to more recently developed tools has been called into question (see Brodaty, Low, Gibson & Burns, 2006).

Several other tests can also be used to assess different areas of cognitive function, including, but by no means limited to:

• The Wechsler Memory Scale
• The California Verbal Learning Test
• Rey Complex Figure
• Clock Drawing Test

Commonly, people who are suspected of having cognitive impairment undergo a "battery" (or set) of tests that investigate a range of cognitive and related abilities (e.g., language, socio-emotional functioning).

It is difficult to recommend a set of screening tools for the recognition of dementia that would be suitable for all clients in all situations. For example, in Indigenous communities in Australia, the KICA assessment tool has been shown to be useful. However, concerns have been raised that some of the symbols used in this test are not entirely meaningful or culturally relevant for older Indigenous people in certain areas of Australia (Department of Western Australia Country Health Service Kimberley, 2006). In addition, the RUDAS scale (Storey, Rowland, Confort, & Dickson, 2004) has been shown to be useful in cognitive screening and assessment of people from CALD (culturally and linguistically diverse) backgrounds. Finally, the GP-Cog is a suitable and validated tool for use by General Practitioners (GPs)-however, it is not well validated for use by other health care professionals (Brodaty, Low, Gibson, & Burns, 2006).

Activity 4

Final note: Although there are many cognitive tests mentioned in the literature, it is important to be aware that not all are valid and/or reliable. All screening and assessment must be conducted by health care practitioners who: (a) are appropriately trained in the use of the tool/test; (b) apply the principles of assessment discussed earlier in this module-including the need for impeccable history taking; and (c) have an appreciation of clinical diagnosis and subsequent implications for the person being tested.

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