Author Dr Emma Fitzsimons
Expert reviewer Dr Dina LoGiudice
Dementia is a syndrome of impairment of brain functions, which may include changes in language, memory, perception, personality and cognitive skills, caused by a range of disease processes.32 In general, consciousness is not impaired but thinking is disordered. Impairment in activities of daily living or in social or occupational functioning are required to meet diagnostic criteria for the International Classification of Diseases, Version 10 (ICD-10) and the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, Text Revision (DSM-IV-TR) respectively.32
In Australia, Alzheimer disease accounts for approximately 50% of cases of dementia. Vascular dementia accounts for another 20%. Some people have features of both and may be described as having ‘mixed’ dementia. Dementia with Lewy bodies causes about 15% of cases and has some distinguishing features such as prominent visual hallucinations and parkinsonian motor signs. Frontotemporal dementia is responsible for 5% of cases but proportionately more cases of early onset dementia, and is distinguished by prominent behavioural symptoms, personality change and impaired executive function. There are also many less common causes of dementia.
A number of medical conditions need to be excluded in people presenting with symptoms or signs or dementia, as treatment may fully or partially reverse the cognitive impairment. Delirium, if present, must be detected and the cause treated. Other conditions that may mimic or exacerbate dementia include thyroid disorders (hypothyroidism or thyrotoxicosis), vitamin deficiencies (most commonly B12 and folate), depression, electrolyte disturbances and normal pressure hydrocephalus. Medications frequently cause or exacerbate cognitive problems.33
People with dementia are at an increased risk of falls (2-fold increase), fracture (3-fold increase), delirium (5-fold increase), depression and epilepsy (6-fold increase). They are also at increased risk of oral disease, malnutrition and weight loss and urinary incontinence. Few studies have been undertaken into the prevalence of dementia in Aboriginal and Torres Strait Islander populations. Zann’s 1987 study reported a prevalence of 20% for dementia or suspected dementia in Aboriginal and Torres Strait Islander people aged over 65 years in northern Queensland.34 Following the development of the Kimberley Indigenous Cognitive Assessment tool, a prevalence study in the Kimberley documented a dementia prevalence of 12.4% in those over aged 45 years and 26.8% in those aged over 65 years, or five times the rate in the overall Australian population.35 In that population, factors associated with dementia included older age, male gender and no formal education. After adjusting for age, gender and education, dementia was associated with current smoking, previous stroke, epilepsy, head injury, poor mobility, incontinence and falls.36 This suggests that population based interventions to reduce the incidence of dementia should include smoking cessation and better control of vascular disease risk factors. Better education for Aboriginal and Torres Strait Islander children may provide some protection from dementia in the longer term, as may interventions to prevent head injury.37
Screening for dementia has not been recommended in guidelines published to date.33,38–40 However, there are increasing calls to consider introducing screening because there is some evidence that early non-pharmacological intervention may improve cognitive outcomes for people with early cognitive impairment. Screening may allow the early detection of reversible causes or exacerbating factors for cognitive decline. Early diagnosis also allows the person with dementia to make plans for the future, including for issues such as enduring power of attorney, while they are still able to do so.41 However, there may be significant stigma associated with a diagnosis of dementia, and by definition, screening involves detecting cases while they are asymptomatic. Older Aboriginal and Torres Strait Islander people have important roles in culture and community and these may be able to continue to be performed adequately when a person has mild cognitive impairment.34 Thus, current guidelines recommend case finding (asking about those with symptoms who may need further evaluation) rather than screening.24,42 Opportunistic case finding should be pursued in Aboriginal and Torres Strait Islander people over the age of 50 years.
Case finding involves being alert for concerns raised by the individual or family members. Cognition is evaluated using a screening tool. The Mini Mental State Examination and the General Practitioner Assessment of Cognition (GPCOG) require English skills and results will be dependent on the level of schooling attained. The Kimberley Indigenous Cognitive Assessment has been developed for use with people living in rural and remote areas, and those who may have had little formal schooling. Interpreters may be required for the assessment.
There is evidence of benefit from cholinesterase inhibitors (donepezil, rivastigmine, galantamine) for the management of mild to moderate dementia. However, there is no evidence that these medications are effective in reducing the risk of dementia in people with mild cognitive impairment and there is no medication intervention that has been shown to be effective in preventing the onset of dementia.43
|Preventive intervention type||Who is at risk?||What should be done?||How often?||Level/strength of evidence|
||Dementia screening is not routinely recommended
|People with symptoms such as memory loss or behaviour change, or if there are concerned family members
||Consider administration of one of the following cognitive screening tests:
- Mini Mental State Examination
- General Practitioner Assessment of Cognition
- Kimberley Indigenous Cognitive Assessment (see Resources)
||People with risk factors for dementia including excessive alcohol intake, tobacco smoking hypertension, diabetes, depression
||Management of dementia risk factors is recommended for multiple health benefits, however, there is limited evidence that this leads to a reduction in dementia incidence
||People without a confirmed diagnosis of dementia
||Anti-dementia drugs are not recommended
Care of patients with dementia in general practice (The Royal Australian College of General Practioners and NSW Health)
Kimberley Indigenous Cognitive Assessment
General Practice Assessment of Cognition
- The Royal Australian College of General Practitioners. Guidelines for preventive activities in general practice (red book), 7th edn. Melbourne: RACGP, 2009. Cited October 2011. Available at www.racgp.org.au/your-practice/ guidelines/redbook/.
- Australian Institute of Health and Welfare. Dementia in Australia: national data analysis and development. Canberra: AIHW, 2006.
- Bridges-Webb C, Wold J. Care of patients with dementia in general practice. Sydney: The Royal Australian College of General Practioners and NSW Health, 2003.
- Arkles R, Pulver LJ, Robertson H, Draper B, Chalkley S, Broe GT. Ageing, cognition and dementia in Australian Aboriginal and Torres Strait Islander peoples: a life cycle approach. Neuroscience Research Australia and Muru Marri Indigenous Health Unit, University of New South Wales, 2010.
- Smith K, Flicker L, Lutenschlager N, et al. High prevalence of dementia and cognitive impairment in Indigenous Australians. Neurology 2008;71(19):1470–3.
- Smith K, Flicker L, Dwyer A, et al. Factors associated with dementia in Aboriginal Australians. Aust N Z J Psychiatry 2010;44(10):888–93.
- Henderson S, Broe G. Dementia in Aboriginal Australians. Aust N Z J Psychiatry 2010;44:869–71.
- Boustani M, Peterson B, Hanson L, Harris R, Lohr KN. Screening for dementia in primary care: a summary of the evidence for the US Preventive Services Task Force. Ann Intern Med 2003 June 3;138(11):927–37.
- National Collaborating Centre for Mental Health. Dementia: A NICE-SCIE guideline on supporting people with dementia and their carers in health and social care. London: NCCMH, 2007.
- Patterson C, Gass D. Screening for Cognitive Impairment and Demential in the Elderly. Canadian Journal of Neurological Science 2001;28(Suppl 1):S42–S51.
- Terpening Z, Hodges JR, Cordato NJ. Towards evidence-based dementia screening in Australia. Med J Aust 2011;194(2):60–1.
- Kimberley Aboriginal Medical Services Council. Dementia (draft version). Kimberley Chronic Disease Therapeutic Protocols. Broome, WA: Kimberley Aboriginal Medical Services Council, 2010.
- Burns A, O’Brien J. Clinical practice with anti-dementia drugs: a consenus statement from the British Association for Psychopharmacology. J Psychopharmacol 2006;20(6):732–55.
- U.S. Preventive Services Task Force. Screening for dementia: recommendations and rationale. Rockville, MD: U.S. Preventive Services Task Force, 2001. Cited October 2011. Available at www.uspreventiveservicestaskforce.org/ 3rduspstf/dementia/dementrr.pdf.
- Brodaty H, Pond D, Kemp N, et al. The GPCOG: A new screening test for dementia designed for general practice. J Am Geriatr Soc 2002;50:530–4.
- LoGuidice D, Flicker L, Thomas J, et al. KICA: Kimberley Indigenous Cognitive Assessment, 2004. Cited October 2011. Available at www.wacha.org.au/docs/misc/KICA-Tool.pdf.
- Ott A, Slooter A, Hofman A, et al. Smoking and risk of dementia and Alzheimer’s disease in a population-based cohort study: The Rotterdam Study. Lancet 1998;351(9119):1840–3.