Visual Perceptual Assessment in Dementia
Research type
Research Study
Full title
Visual Perceptual Assessment in Dementia
IRAS ID
281385
Contact name
Jonathan Evans
Contact email
Sponsor organisation
University of Glasgow
Duration of Study in the UK
0 years, 10 months, 29 days
Research summary
Summary of Research
Although memory loss is commonly associated with dementia, other symptoms can also be caused by dementia. One of these is visual impairment. While there are several tests of memory available, there are fewer tests to measure visual impairment in people with dementia. The Addenbrooke’s Cognitive Examination (Third Edition: ACE-III; Hsieh et al., 2013), claims to do this as part of a broader screening of cognitive functions. This study aims to evaluate how well the ACE-III can detect visual impairment in people with dementia. If the ACE-III is effective at this, then people with dementia who have visual impairment should have lower scores on the test than people with dementia who don’t have visual impairment.This study will use only existing data routinely collected as part of clinical assessments for dementia.
Participants will include individuals who have been diagnosed with dementia or mild cognitive impairment (MCI), and who received their diagnosis following completion of neuropsychological assessment (including the ACE-III). Clinical psychologists based within each older adult community mental health team (OACMHT) within NHS Greater Glasgow and Clyde (GG&C) will be asked to provide a list of individuals in their service who meet the inclusion criteria. Caldicott Guardian approval has already been given in relation to accessing and including the routinely collected clinical data of patients who have completed neuropsychological assessments for dementia. On the basis of test results from the detailed neuropsychological assessment participants will be categorised as belonging to one of two groups:
Group 1: Visual impairment group
Group 2: Non-visually impaired groupGroup 1 scores on the ACE-III will then be compared with Group 2 scores. If the ACE-III is able to show which people have visual impairment and which people do not, then Group 1 (Visual impairment) should have lower scores than Group 2 (Non-visually impaired).
Summary of Results
Diagnostic Accuracy of the Visuo-spatial domain of the Addenbrooke's Cognitive Examination IIIBackground
Many people diagnosed with dementia will experience some form of visual impairment, with visuo-spatial function among the most common visual process affected (Geldmecher, 2003).Accurate measurement of visuo-spatial ability is essential therefore to inform clinical judgement and may also assist with differential diagnosis and management of risk. However, the evidence base for tests of visuo-spatial ability is relatively limited. The Addenbrooke's Cognitive Examination (third edition: ACE-III; Hsieh et al, 2013) is a widely used screening tool for symptoms of neurocognitive decline, and although this includes a measure of visuospatial ability it is unclear how accurately this detects visuo-spatial impairment in individuals with dementia and Mild Cognitive Impairment (MCI).
Aims
The study aimed to assess how well the ACE-III detects visuo-spatial deficits in individuals with dementia and MCI. In addition, the study aimed to identify the optimal cut-off score for interpretation of ACE-III visuo-spatial performance and identification of visuo-spatial impairment.What the study involved
The electronic health records of individuals diagnosed with dementia or MCI were accessed in order to obtain pre-existing scores on the ACE-III visuo-spatial domain. Results from other detailed neuropsychological tests of visuo-spatial function were used to assign participants to either a visual impairment (VI) group or a no impairment (NI) group. A total of 49 people were 44 allocated to the visual impairment group while 103 people were allocated to the no impairment group. Scores obtained by each group on the ACE-III visuo-spatial sub-test were then compared.Results
The VI group performed significantly more poorly than the NI group on the ACE-III visuospatial sub-test. The ACE-III showed 'fair' diagnostic accuracy for detecting visuo-spatial impairment. The optimal cut-off score was 12.5, whereby individuals obtaining scores of 12 or below are likely to display visuo-spatial impairment.Conclusions
The study demonstrated that the ACE-III is an adequate measure of visuo-spatial impairment in individuals with dementia and MCI. However, this should be used alongside more extensive neuropsychological assessment in cases where screening measures indicate the requirement for additional testing of dementia symptoms.References
Bowen, M., Edgar, D.F., Hancock, B., Haque, S., Shah, R., Buchanan, S., Iliffe, S., Maskell, S., Pickett, J., Taylor, J.P., & O'Leary, N. (2016). The Prevalence of Visual Impairment in People with Dementia (the PrOVIDe study): A cross-sectional study of people aged 60-89 years with dementia and qualitative exploration of individual, carer and professional perspectives. Health Services and Delivery Research, 4(21) Geldmacher, D.S. (2003). Visuo-spatial dysfunction in the neurodegenerative diseases.
Frontiers in Bioscience, 8: 428-436REC name
West of Scotland REC 1
REC reference
20/WS/0156
Date of REC Opinion
5 Nov 2020
REC opinion
Favourable Opinion