Dementia Flashcards
What is dementia?
Dementia is a syndrome
Usually of a chromic or progressive nature
And it is deterioration of cognitive function beyond what might be expected from normal ageing
Consciousness is not affected in dementia, this is what helps distinguish it from delirium!
What age is classed as early onset dementia?
The onset of dementia before 65 years
What could you use to screen dementia in the community?
GPCOG (general practitioner assesment of cognition)
Or
6-CIT (six item cognitive impairement test) use if they have attended alone
What can you do in secondary care to diagnose dementia?
If Minimal cognitive impairement is possible then do MoCA (montreal cognitive assesment)
You can use MMSE if minimal cognitive impairement isn’t a possibility but Moca is still preferable
What investigations should be done for dementia?
Routine bloods- FBC, U and Es, Ca2+, glucose, LFTS, TFTS, 12 and folate
If clinically appropiate, the following can be done…
- MSU (UTI)
- CXR (pneumonia)
- serology for syphilis or HIV
- ECG (exclude AF in the contents of vascular dementia)
- neuro-imaging MRI for the subtype of dementia, CT scan for cognitive impairement
What is the management of dementia?
Treat by aetiology as appropriate
Offer advice and support
Make sure they contact DVLA for assesment and stop drving
Refer urgently to neurology if- rapidly progressing or there are neurological signs or symptoms
How do you manage mild cognitive impairement?
Refer to the memory clinic for long term monitoring and early detection
They can continue to drive if safe to do so, don’t need to notify the DVLA.
What are the subtypes of dementia?
Alzheimers (most common-62%) Vascular Mixed Lewy bodies Fronto- temporal
What is alzheimers disease?
A primary neuro degenerative disease which is the commonest cause of dementia
Not really sure what causes it, however genetics are important
Around 15% are thought to be familial
Has a link with autosomal dominant and early onset
What genes are associated with early onset alzheimers disease?
APP
PSEN1
PSEN2
All of these genes are associated with beta amyloid
What is the histopathology behind alzheimers disease?
Neurofibrillary tangles- intracellular accumulations of abnormally folded Tau proteins
Beta amyloid plaques - extracellular abnormal proteins
What is the gene associated with later onset of alzheimers?
APOE
What are the risk factors for alzheimers disease?
Age- usually >65 years old, the risk increases with age!
Family history- increased risk with first degree relatives, even without APOE
Mild cognitive impairement
Risk factors for CVD
Previous traumatic brain injury
Fewer years of formal education
Down syndrome
What is the typical history of someone with alzheimers disease?
Memory loss which is gradual and episodic, they have problems remembering recent events rather than distant memories
May also have cognitive deficits and may have hallucinations however hallucinations are more strongly associated with lewy body dementia
What investigations can be done for dementia?
MRI should be performed to rule out other causes for the presentation
CT is an acceptable alternative
On MRI and CT look for cortical atrophy (shown by enlargement of the sulci), cortical atrophy can be seen in dementia however it can also be seen in an older person generally anyway
On MRI look for focal medial temporal lobe atrophy as this is more specific, can differentiate Alzheimers from dementia with lewy body or vascular dementia
What is the management of alzheimers?
Alzheimers can be treated with cholinesterase inhibitors, these do not slow down the progression however they can improve cognitive function
1st line= donepezil
2nd line= rivastigmine or galantamine
How do cholinesterase inhibitors work?
They work by inhibiting the enzyme acetyl cholinesterase, which normally breaks down acetylcholine and therefore increase the levels of neurotransmitter acetylcholine
What is used to treat severe Alzheimers disease?
Memantine
This is a receptor antagonist which prevents NMDA stimulation by glutamate
In alzheimers there is excess glutamate
Can also be used in mild/ moderate alzheimer patients who can’t tolerate cholinesterase inhibitors usually due to GI symptoms.
What is vascular dementia?
This is an umbrella term for dementia secondary to cerebrovascular disease
What causes vascular dementia?
Multiple infarctions- dementia develops after multiple strokes(multi infarct dementia)
Patients may have microvascular disease (most common vascular dementia)
Mixed dementia= AD + vascular dementia
What are the risk factors for vascular dementia?
Same as for CVD- hypertension, hypercholesterolaemia, diabetes, obesity etc…
Past stroke - both haemorrhagic and ischaemic
The risk increases with each stroke
Stroke risk factors are also relevant- atrial fibrillation and carotid artery stenosis
What is the hx normally for vascular dementia?
Stepwise decline in cognitive function, in contrast to the gradual decline seen in alzheimers disease
The exact symptoms and signs depends on the size and the location of the lesion
Memory impairement may occur but is often mild
What may you find on examination of someone with vascular dementia?
There may be signs of past stroke- unilateral signs of past stroke
Assess the cardiac rythm (AF)
Auscultate the carotids for bruits
What Ix are done for vascular dementia?
ECG for AF
MRI should be requested to see the extent of CVD and also look for old infarcts, CT is again an acceptable alternative
What is the management of vascular dementia?
Control the risk factors for progression and optimise the cardiovascular health
What is dementia with lewy bodies?
This is a neurodegenerative condition, which is somewhat related to parkinsons disease
What causes lewy body dementia?
Deposition of lewy bodies in the cortex
Both lewy body dementia and parkinsons are associated with lewy body deposition, what is it which makes them different?
DLB= a cortical deposition PD= lewy bodies are deposited in the substantia nigra
What are the risk factors for lewy body dementia?
Age >65
Few other known risk factors
Often no FHx
What is the classical Hx of someone with dementia with lewy bodies?
Impaired attention and alertness which fluctuates
There is often hallucinations of people/animals
+/- delusions
Compared to alzheimers disease there is less memory impairment and a faster progression
REM sleep behaiour (associated with both alzheimers and lewy body) acting out dreams when asleep
What may you see on examination of someone with dementia with Lewy bodys?
The patient may have parkinsonism…
Bradykinesia
Resting tremor
Rigidity
How do you determine whether a patient has lewy body or parkinsons disease?
Depends on the timing of cognitive and motor symptoms
Dementia w/ Lewy body- if cognitive symptoms are before or occur alongside the motor symptoms
Parkinsons-if motor changes before the cognitive impairement
What is the management of dementia with lewy bodies?
Avoid antipsychotics because they are more likely to develop the side effects
Cholinesterase inhibitors can be used for non cognitive symptoms
What is the histopathology behind frontotemporal dementia?
Also called Picks disease
You get Pick bodies (tau) in the temporal and frontal lobes
What does frontotemporal dementia usually present with?
Onset is at 45-65 years old
You will get prominent frontal lobe symptoms and signs, the patient becomes disinhibited and becomes difficult in regulating their own behaviour and becomes socially inappropriate
What is progressive supranuclear palsy?
This is another tauopathy
It is also a parkinson plus syndrome (neurodegenerative condition with features of parkinsonism)
However Poor response to parkinsons disease treatment
It is atypical parkinsonism
What are the clinical features of progressive supranuclear palsy?
Postural instability- falls backwards
Staring/startled expression
Vertical gaze palsy
Dementia is a later feature
What is wernickes encephalopathy?
Presence of neurological symptoms caused by biochemical lesions of the CNS due to a thiamine deficiency
What causes wernickes encephalopathy?
Alcoholism
Poor nutrition
What does wernickes encephalopathy present like?
Confusion, ataxia, opthalmoplegia
How do you manage wernickes encephalopathy?
IV thiamine
If this doesn’t happen then korsakoffs syndrome can occur, which causes Anterograde amnesia (patient can no longer lay down new memories)
Patient will also have confabulations (patient works around memories by filling in the blanks), possible with details from intact memories
What is normal pressure hydrocephalus and what does it result in?
It is where there are enlarged ventricles in the brain however there is a normal pressure on lumbar puncture
It is a progressive triad of abnormal gait, urinary incontinence and dementia
It is a potentially reversible cause of dementia and therefore patients should be referred for shunt surgery!
What is CJD?
Creutzfeldt- Jakob Disease
This is a prion disease
Most cases are sporadic (no known risk factors)
Some cases are hereditary
Acquired is very rare
What do patients with CJD present with?
Severe cognitie dysfunction…
- myoclonic jerks
- sensory symptoms
What is chorea?
Abnormal involuntary movement disorder
What is Huntingtons disease?
Progressive brain disorder which is caused by a defective gene
Trinucleotide repeat in Huntington gene
Autosomal dominant
Onset is 30-50 years old
Presents with…
Chorea
Psychiatric symptoms
Dementia
