☰ Table of contents
Recommendations: Dementia
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Preventive intervention type
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Who is at risk?
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What should be done?
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How often?
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Level/ strength of evidence
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References
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Screening
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Asymptomatic people |
Dementia screening is not routinely recommended |
|
IIC |
56, 65 |
People with any of the following:
- symptoms such as memory loss or behaviour change
- concerned family members
- history of repeated head trauma
- Down syndrome
- elevated cardiovascular risk
- depression or a history of depression
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Over several consultations, obtain history from the person and their family, and perform a comprehensive physical examination
Consider administration of one of the following cognitive screening tests:
- Mini Mental State Examination (MMSE)
- General Practitioner Assessment of Cognition (GPCOG)
- Kimberley Indigenous Cognitive Assessment-Cog (KICA-Cog) or modified KICA-Cog (Refer to ‘Resources’)
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Opportunistic |
IIIC |
5, 66, 67 |
Behavioural
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People with risk factors for dementia including excessive alcohol intake, tobacco smoking, hypertension, diabetes, depression
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Recommend the following for prevention and early intervention:
- regular physical activity (150 minutes per week of moderately intense walking or equivalent)
- increased social engagement and activities
- cognitive training and rehabilitation
- diet – Mediterranean diet has been shown to be effective
- smoking cessation
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Opportunistic
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GPP
|
5
|
Chemo-prophylaxis
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People without a confirmed diagnosis of dementia |
Anti-dementia drugs are not recommended |
|
IB |
68 |
Background
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.46 In general, consciousness is not impaired but thinking is disordered. Impairment in activities of daily living are required to meet diagnostic criteria for the International Classification of Diseases, 10th Revision (ICD-10).47 The Diagnostic and statistical manual of mental disorders, 5th edition (DSM-5), renames dementia as major neurocognitive disorder, and its diagnosis requires interference with independence with everyday activities (at a minimum, requiring assistance with complex instrumental activities of daily living such as paying bills or managing medications).48
In Australia, Alzheimer’s 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 (protein deposits in nerve cells in brain regions responsible for cognitive and motor functions) causes about 15% of cases and has some distinguishing features such as prominent visual hallucinations, marked fluctuations and Parkinsonian motor signs. Frontotemporal dementia is responsible for less than 5% of cases but proportionately more cases of early onset dementia, and is distinguished by prominent behavioural symptoms, language difficulties, personality change and impaired executive function. There are also many rarer causes of dementia.
A number of medical conditions need to be excluded in people presenting with symptoms or signs of 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.
People with dementia are at an increased risk of falls, fracture, delirium, depression, and epilepsy. They are also at increased risk of oral disease, malnutrition and weight loss, and urinary incontinence.
Following the development of the Kimberley Indigenous Cognitive Assessment (KICA) tool, a prevalence study in the Kimberley documented a dementia prevalence of 12.4% in those aged over 45 years and 26.8% in those aged over 65 years, or five times the rate in the overall Australian population.47 This has been followed up by a study in urban and regional New South Wales using a modified form of the KICA, which demonstrated an age-standardised rate of 21% in Aboriginal people aged 60 years and older, three times the rate in the general population.49 In this study, which involved specialist clinical assessment, types of dementia diagnosed were similar to those for the general population, with 44% being diagnosed with Alzheimer’s disease and 17% with vascular dementia. In the Northern Territory, a data linkage study of the population has demonstrated a higher incidence and prevalence of dementia in Northern Terrritory Aboriginal and Torres Strait Islander people, with higher rates at younger ages.50
In the Kimberley remote population, factors associated with dementia included older age, male gender and no formal education. After adjusting for these factors, dementia was independently associated with current smoking, previous stroke, epilepsy, head injury, poor mobility, incontinence and falls.51
At follow-up five years later, risk factors for declining cognition were stroke, head injury, analgesic medication, low BMI and higher systolic blood pressure.52
Interventions
Population-based interventions for preventing the onset of dementia are a new area of interest. Increased levels of education are protective against dementia, a finding which seems robust and cross-cultural,53 and so increasing the access of Aboriginal peoples to education is likely to reduce their future risk of dementia. Vascular risk factors such as smoking and diabetes are strongly associated with dementia risk, and population-based interventions are likely to be useful. In fact, because of the long time to develop the changes leading to dementia, many of the recommendations to reduce risk are best enacted in midlife.
Other preventive interventions include management of depression, improving social engagement, and cognitive training exercises.5
An Australian evidence-based self-assessment tool developed by the Australian National University called the Alzheimer’s Disease Risk Index (ANU-ADRI) can be used by individuals or clinicians to assess risk factors and protective factors for Alzheimer’s disease.54 The ANU-ADRI includes assessment of risk factors such as family history, education attainment and history of head injuries, but also modifiable lifestyle factors such as activity levels, social engagement and cognitive activity. It takes approximately 10–15 minutes to complete. Participants receive feedback regarding protective factors and factors that can be modified to decrease risk. It can be used to guide participants to engage in risk-reduction activities but it is not intended to be used as a screening or diagnostic tool and it has not been validated in Aboriginal and Torres Islander peoples. It could be included in a well person’s check along with cardiovascular risk calculation.55 More research is needed to assess its effectiveness on clinical outcomes.
Routine well-person’s screening for dementia is not recommended in current guidelines.56 However, early case finding is important because there is some evidence that early non-pharmacological intervention may improve cognitive outcomes for people with early cognitive impairment. Early case finding allows 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.57 In a non-Indigenous cohort the delay between family members noticing symptoms of dementia and the person receiving a diagnosis averaged over three years.58 This is unlikely to be shorter for Aboriginal people, and so awareness of concerns from family members and enquiring about memory is important.5
There may be significant stigma associated with a diagnosis of dementia. Older Aboriginal and Torres Strait Islander people have important roles in culture and community and these could continue to be performed adequately when a person has mild cognitive impairment.59 Thus current guidelines recommend a case-finding approach (conducting further evaluation in those presenting with symptoms) rather than screening.5 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 (MMSE) has been evaluated in urban and regional New South Wales Aboriginal populations and has good sensitivity and specificity.60 The KICA tool has been developed for use with people living in remote areas and those who may have had little formal schooling.61 It has also been modified for Aboriginal peoples living in urban and regional Australia and performs well.60 Interpreters may be required for the assessment.
There is evidence of benefit from cholinesterase inhibitors (donezpeil, rivastigmine, galantamine) for symptomatic management of mild to moderate dementia, particularly in Alzheimer’s disease and Lewy body 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.62–64
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