Dementia is a neurodegenerative disorder characterised by a decline in cognition, affecting two or more of the following domains: the ability to store and remember new information (learning and memory); language functions; reasoning, judgment and performing complex tasks (executive functioning); perceiving and processing spatial information; behaviour and personality. The decline in cognitive functioning interferes with daily functioning and cannot be explained by a delirium or depression.
The most common form of dementia in older adults is Alzheimer’s disease (AD). The hypothesis is that it is caused by beta-amyloid plaques in the brain which disturb the communication between braincells. MRI imaging shows atrophic changes in the hippocampus to begin with, followed by changes throughout the cortex. Alzheimer’s disease typically progresses slowly, over months and years and the most common symptom is memory problems. Language issues, executive functioning and orientation problems also commonly exist in this disease. The second most common form of dementia is vascular dementia due to cerebrovascular damage. Because both small and large vessels can be affected, symptoms can vary and fluctuate widely. In elderly patients, mixtures of AD and vascular dementia are not uncommon. Rarer causes of dementia are Lewy body dementia and frontotemporal dementia.
Mild cognitive impairment (MCI) is a state in which someone might have (objective) cognitive impairments but preserved daily functioning. Some subtle changes in cognition may occur in normal ageing. MCI can be a precursor to dementia but, in over 50% of patients, this is not the case. It is not possible to reliably predict which patients with MCI will develop dementia.
The diagnostic process can be performed by the GP or in consultation with a geriatric specialist, if needed. Hetero-anamnesis is essential but the diagnosis cannot be established without repeated consultations with the patient themselves. Diagnosis requires objective assessment of cognitive functioning. Commonly used instruments are the Mini Mental State Examination (MMSE) and the clock drawing test. The RUDAS test may also be considered. Physical examination is aimed at signs indicative of dementia (e.g. head turning sign, actions during dressing and undressing, recognition of objects in the room; pay attention to a patient’s personal care) and / or signs of other causes for memory problems (delirium, depression, psychosis, subdural haemorrhage). More extensive (neurologic) investigation and blood tests are performed on indication. Routine imaging is not recommended.
Providing information about the diagnosis and prognosis to the patient and their caregivers is important once dementia is diagnosed. Case-management and personal guidance to the patient and caregivers should be offered. In the Netherlands, dementia case-managers are regionally available. The effects of non-medicamental therapy, such as occupational or movement therapy are uncertain but these therapies may improve the patients’ daily routine and wellbeing. Day-care and other non-medicamental options may also be supportive to a patient’s caregivers. Part of the education offered to patients and their caregivers may be to explain that treatment with anticholinesterases is not effective. An individual care plan can help clarify and prioritise problems. It can also help to get an overview on the (in)formal caregivers involved and align actions.
Referral may be helpful in case of diagnostic uncertainty (e.g. symptoms at a younger age or a suspected rare cause of dementia), in case of (psychiatric) comorbidity, problematic behaviour or in case of legal incapacity and involuntary care.
In ICPC-2, dementia is coded P70. Memory disturbance, including mild cognitive impairment is coded P20.
Dementia is a disease of the elderly. It has an incidence of 0.7 per 1000 patient years (less than one new diagnosis per 1000 patients per year). New diagnoses in patients under the age of 65 are rare. Among patients aged 65-74, the incidence is 1.5 per 1000 patient years. Over the age of 75, the incidence is 12.2 per 1000 patient years. Link/Figure 1
The prevalence of dementia is 3.7 per 1000 patient years. In the age group 75+, the prevalence is 64.4, meaning that among 1000 patients aged 75+, 64 seek help from their GP for dementia during a year. Link/Figure 2
Dementia is ranked 26th in the list of the most prevalent conditions among patients aged 75+. Link/Table 3
Its higher prevalence when compared to incidence indicates that dementia is a chronic disease requiring GP attention throughout the years.
The most common presented symptom of dementia is memory disturbance (P20) which is the initial reason for encounter (RFE) in 14% of all new episodes of dementia. More commonly, the initial RFE is an administrative procedure (*62), which might imply (the request for) some note or declaration, or the problem is brought to the attention by someone else (*65), for example, a patient’s partner or child.
These are RFEs in 21% and 20% of new episodes of dementia, respectively. Link/Table 4 The GP sometimes raises the topic (*64, in 13%). This is more common in women with dementia (Link/Table 5), whereas in men, an administrative procedure and initiation by someone else are more common reasons for encounter. Link/Table 6 A possible but speculative explanation could be that men with dementia are more likely than women with dementia to be surrounded by concerned loved ones (informal carers) who raise the issue. Women with dementia sometimes present with a request for medical examination (e.g. cognitive testing, *31). In younger patients with dementia, the initial RFE is most commonly memory disturbance (P20, in 30% of episodes), suggesting that patients themselves experience symptoms and raise the issue, but the absolute numbers are very small. Link/Table 7
Prescription of medication (*50) occurs in 33% of episodes of dementia. Other common interventions apart from health education (*45) and medical examination (*31) are referral to (*66) and consultation with (*46) primary care health providers (in 27% and 20% respectively) and referral to (*67) and consultation with (*47) specialists in secondary care (in 18% and 9% of the episodes, respectively). Administrative interventions (*62) are also common (19%). Blood tests (*34) occur in 15% and therapeutic counselling / listening (*58) in 9%. All percentages are calculated per calendar year. Link/Table 8 This variety of interventions reflects the substantial workload for GPs in the care for patients with dementia.
Prescribed medication concerns mostly anti-dementia drugs such as anticholinesterases (N06D), followed by antipsychotics (N05A). Other prescribed medication includes antidepressants, vitamins, anxiolytics and sedatives. Link/Table 9
Referrals to primary care providers are commonly to an ‘other’ or unknown care provider (in 15%, annually) – probably the dementia case-manager in most cases. Other primary care referrals involve occupational therapy, physical therapy, home care and elderly care medicine. Link/Table 10 Secondary care referrals are mainly to geriatric medicine (in 8%) and to psychiatry. Link/Table 11 The information on this website does not make it possible to distinguish the specialities that are consulted (without referral) in primary (*46) or secondary care (*47). This would be possible in additional data extractions.
Dutch guideline: https://richtlijnen.nhg.org/standaarden/dementie#volledige-tekst (2020)
