Dementia Flashcards
How common is it?
In the UK 2014: 835,000 people living with it (62% female, 38% male).
Who does it affect?
The total age-standardised population prevalence of dementia in people 65 years of age and older is 7.1%. Between a third and half of people with dementia live in care homes. 42,325 are younger than 65.
What causes Alzheimer’s?
50-75% have it
Atrophy of the cerebral cortex and formation of amyloid plaques and neurofibrillary tangles. Acetylcholine production in affected neurons is reduced.
What causes vascular dementia?
20% have it
Occurs as a result of reduced blood supply to the brain. It can be caused by a wide range of cerebrovascular disorders, including large or multiple small infarcts, cerebral amyloid angiopathy, and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.
What causes dementia with Lewy bodies (DLB)?
10-15%
The second most common degenerative type. The main pathological features of DLB are cortical and subcortical Lewy bodies. DLB may have similar features to Parkinson’s disease dementia.
What other types of dementia are there?
Frontotemporal dementia (FTD) (2%), Parkinson’s disease dementia. Progressive supranuclear palsy. Huntington’s disease. Prion disease. Normal pressure hydrocephalus. Chronic subdural haematoma. Benign tumours. Metabolic and endocrine disorders (such as chronic hypocalcaemia and hypoglycaemia). Vitamin deficiencies (such as B12 and thiamine).
What risk factors are there?
Age (strongest risk factor). Mild cognitive impairment. Learning difficulties. Genetics (especially for young onset, 86% have a mutation in the amyloid precursor protein gene), Also APOE4 for Alzheimer’s disease. Cardiovascular disease (CVD) risk factors (such as diabetes, smoking, hypercholesterolemia, and hypertension). Parkinson’s disease. Stroke. Depression. Heavy alcohol consumption. Low educational attainment. Low social engagement and support.
How does it present?
Cognitive impairment, including: Memory problems, the person may defer to family when answering questions, have difficulty learning new information or remembering recent events or people’s names, be vague with dates and or miss appointments. Receptive or expressive dysphasia. Difficulty in carrying out coordinated movements such as dressing. Disorientation in time and place. Impairment of executive function, such as difficulties with planning and problem solving.
Difficulties with activities of daily living.
Behavioural and psychological symptoms of dementia (BPSD) tend to fluctuate, may last for 6 months or more and may include: Psychosis, agitation and emotional liability, depression and anxiety, withdrawal or apathy, disinhibition, motor disturbance, sleep cycle disturbance or insomnia and tendency to repeat phrases or questions.
Investigations
Assess for capacity for each decision.
Also apparently specialist investigation for structural imaging (MRI or CT) should be used to exclude non-dementia cerebral pathology such as normal pressure hydrocephalus, but I can’t imagine that’s done routinely.
Identify the type (which can be possible from history)
Treatment
Antipsychotics are bad and don’t work (only used if individual is severely distressed or there is an immediate risk of harm to the person or others.
Acetylcholinesterase inhibitors (donepezil, galantamine and rivastigmine) can be used for mild to moderate Alzheimer’s disease.
If this is contraindicated, or for severe Alzheimer’s disease, then Memantine (a N-methyl-D-aspartic acid receptor antagonist) can be used.
Conditions that would present similarly
Normal-age related memory changes. Mild cognitive impairment. Depression. Delirium. Vitamin deficiency. Hypothyroidism. Adverse drug effects (e.g. benzodiazepines, analgesics, anticholinergics, antipsychotics, anti-convulsants and corticosteroids can effect cognition. Normal pressure hydrocephalus. Sensory deficits.
