Dementia Flashcards
What is the epidemiology of dementia?
- The number of people living with dementia worldwide is estimated to be 47.5 million this is projected to increase to 75.6 million by 2030
- There are 850,000 people with dementia in the UK equates to 1 in every 79 people
- The cost of dementia to the NHS is £26 billion per year
- The proportion of people with dementia doubles for every 5 year age group
- 1/3 of people aged >95yr have dementia
- 2/3 of people who have dementia are women
- There will be over a million people with dementia in 2025
- The prevalence is 5% over the age of 65 and 20% over 80
- 15,000 younger people have dementia in the UK
- 60,000 deaths a year are attributable to dementia and 64% of those living in care homes have some form of dementia
- Family carers of patients with dementia are estimated to save the NHS over £6 billion a year
- Most common form of dementia is Alzheimer’s disease affecting 500,000 people in the UK with vascular dementia second affecting 150,000 people in the UK
What is the definition of dementia?
Severe impairment or loss of intellectual capacity and personality integration, due to the loss of or damage to neurones in the brain loss of cognitive ability in a previously unimpaired person beyond what might be expected from normal ageing
• The word dementia describes a set of symptoms that may include
o Memory loss
o Difficulties with thinking
o Problem-solving
o Language
What is the DSM-5 diagnostic criteria for dementia?
o Evidence of impairment of memory and a least one of Language impairment Apraxia Agnosia Impairment of executive function Impairment of functioning No other medical or psychiatric explanation Present for at least 6 months
What is mild cognitive impairment (MCI)?
When there is evidence of early memory decline on formal memory testing (eg. MMSE) 10-15% with MCI develop dementia within a year
Mild memory problems can be an indication of the early stages of dementia or may be due to problems with depression, anxiety, stress or a physical problem
What is the classification of dementia?
Primary dementia- dementias that are not due to an alternative cause
Secondary dementia- dementias that occur as a result of physical disease or injury
Cortical dementia- dementias causing with memory, language, thinking & social skills
Subcortical dementia- dementias causing problems with emotions, movements and memory problems
Progressive dementia- dementias that deteriorate over time
What is Alzheimer’s dementia?
62%
Most common type of dementia affecting 500,000 people in the UK- risk of developing AD increases with age
approx. 95% of patients with AD are >65yrs characterised by plaques and tangles in the brain cause is unknown
What is vascular dementia?
17% 2nd most common type of dementia often progresses in a stepwise manner caused by reduced blood supply to the brain due to diseased blood vessels symptoms may develop suddenly – eg. after a stroke, or more gradually, such as with small vessel disease o Post-stroke dementia o Single infarct dementia o Multi-infarct dementia o Sub-cortical dementia
What is mixed dementia?
Mixed dementia (10%)- a combination of Alzheimer’s and Vascular dementia
What is Lewy body dementia?
4%
this affects approx. 25,000 people in the UK many of the symptoms are similar to those of AD – eg. memory deterioration, poor attention and communication difficulties often show symptoms of Parkinsonism and hallucinations due to spherical deposits of protein, but of unknown cause
What are the rare types of dementia?
3%
o Creuztfeldt Jakob
o Huntington’s disease
o Dementias associated with high alcohol intake Karsakoff’s
o Dementias related to reversible conditions, such as B12 deficiency or hypothyroidism
Frontotemporal (2%)- rare form of dementia and actually describes a variety of conditions it includes
Pick’s disease- it is more common in adults <65yrs the early signs are personality & behaviour changes as opposed to memory decline and difficulties in language
• Parkinson’s (2%)
What is the aetiology of degenerative causes of dementia?
Alzheimer’s Disease Frontotemporal dementia Lewy Body Dementia Parkinson’s Disease Huntington’s disease Progressive supranuclear palsy
What is the aetiology of the vascular causes of dementia?
Multi-infarct dementia Cerebral infarcts Binswanger’s disease Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) Vasculitis eg. lupus
What are the characteristics of early onset Alzheimer’s disease?
Rare compared to late onset Alzheimer’s
• Autosomal dominant
• The 3 genes are:
Amyloid precursor protein (APP) chromosome 21
Presenilin gene 1 (PSEN-1) chromosome 14
Presenilin gene 2 (PSEN-2) chromosome 1
If one of these genes is present, then the disease is developed aged 30-40yrs
If 2 or more close relative develop Alzheimer’s below the age of 60- a patient should be considered for genetic screening
What are the characteristics of late onset Alzheimer’s disease?
This is classified as Alzheimer’s disease developing in the over 65’s and is the most common form, responsible
for 99% of all Alzheimer’s disease
Its development is linked to the apolipoprotein E gene (APO-E)
There are 3 types: APO-E2, APO-E3 and APO-E4. Everyone has two copies of the gene and these may be of the same type or different
What is APO-E4 associated with?
APO-E4 is associated with a higher risk of Alzheimer’s. About 25% of people inherit a single copy of this gene and this will increase their risk of Alzheimer’s by up to 4 times. 2% of the population will inherit 2 APO-E4 genes, one from each parent, and this will increase the risk of Alzheimer’s by about 10 times
What is APO-E3 associated with?
The APO-E3 gene is inherited in a double form by 60% and approximately 50% of this group will develop
Alzheimer’s by their late 80’s
What is APO-E2 associated with?
APO-E2 is mildly protective against Alzheimer’s. 11% of the population have 1 copy and 0.5% have 2 copies of it
What are the characteristics of vascular dementia?
Single-gene defects are responsible for rare variants of the disease
The Notch3 gene is linked with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)
A variation in the APP gene causes heritable cerebral haemorrhage with amyloidosis (HCHWA)
Hypercholesterolaemia, hypertension and diabetes contribute to the development of vascular dementia and all of these have a genetic component
What are the other causes of dementia?
Down’s syndrome- patients with trisomy 21 have a 50% change of developing Alzheimer’s by their 6th
decade
Huntingdon’s disease- autosomal dominant with a defect in Huntingtin gene dementia can occur at any stage, but often present quite young offspring of affected patients have a 50% probability of developing the condition
Frontotemproal dementia- these are strongly heritable a number of faults of the tau gene have been implicated
What are the symptoms of Alzheimer’s disease?
o Forgetting names, people, places o Repetitive o Misplacing items in odd places o Confusion about time of day o Getting lost o Problems with word finding o Mood or behaviour problems
What are the symptoms of vascular dementia?
o Problems with planning or organising, making decision or solving problems
o Difficulties following a series of steps eg. cooking a meal
o Problems concentrating including short periods of sudden confusion
What are the symptoms of Lewy body dementia?
o Hallucinations
o Attention
o Mood swings
o Deterioration of physical abilities- similar to Parkinson’s disease
What are the risk factors for dementia?
Smoking- increases the risk of mental decline/atherosclerosis
Alcohol- large amount increases risk, moderate is protective
Atherosclerosis- vascular and perhaps Alzheimer’s
Hypercholesteroiaemia- increases risk of vascular and Alzheimer’s
Age- particularly Alzheimer’s/vascular
Genetics
Mild cognitive impairment
What are the early phases of symptoms?
o Difficulty embracing change
o Repetition of questions
o Short term memory loss
