Dementia Flashcards
What is dementia?
fatal neurodegenerative disorder that is characterised by progressive cognitive, social and functional impairment
What is the most common cause of dementia?
what is cognitve syndrom in this cause?
Alzheimer’s disease
Cognitive syndrome: loss of volume in hippocampus and entorhinal cortex
Is there a cure for dementia?
NO
but acetylcholinesterase inhibitors have modest symptomatic benefit in early stages (MMSE 1)
How does dementia presentation change with age
Young Onset have more Familial AD and Frontotemporal than Late onset.
YOD also has other causes (maybe rare)
Late onset is predominantly AD
What are the common causes of dementia?
- Alzheimer’s disease
- vascular dementia
- frontotemporal dementia
- dementia with Lewy bodies
N.B. there are other niche causes
What are some potentially reversible causes of dementia?
- depression
- alcohol related brain damage
- endocrine (hypothyroidism, Cushing’s, Addison’s)
- B1/B12/B6 deficiency
- benign tumours
- normal pressure hydrocephalus
- infections
- limbic encephalitis
- inflammatory
Describe the continuum of dementia (i.e. different ways of cognitive decline)
Normally, there is a general decrease of cognitive function with age.
However with dementia:
> preclinical deterioration in cellular function until clinical manifestation (amyloid, tau)
> This leads to subtle cognitive deficit, MCI
> Evetually to dementia
Why is is hard to diagnose dementia in the clinic?
- disease follows a heterogenous course
- in old age disease presentation is of multiple co-morbidities
- lots of mixed uncertain pictures (MI, hypertension)
- younger patients are more typical
What are some molecules involved in the pathology of dementia?
- beta amyloid proteins (more in brain and less in lumbar puncture)
- tau protein (form most of the neurofibrillary tangles)- high in lumbar puncture
Lewy bodies- a-synuclein- but not specific
N.B. there are other molecules but they are not as prevalent
What is the process for diagnosis of dementia?
- referral (GP/psychiatrist)
- history
- examination
- investigation
- diagnosis- can repeat over the course of 6 months to 2 years
- management
What are important things to check when interviewing a suspected dementia patient?
- memory
- collateral history- VERY important
- language (word finding difficulty)
- numerical skills
- executive skills
- personality
- sexual behaviour
- mood
- delusions/hallucinations
- chronology of each
What is involved in examination for dementia?
- neurological mental state
- focus tests
- limb functions
- appearance, behaviour, speech, insight
What are some investigations for dementia?
- neuropsychology
- bloods
- MRI
- PET
What are some cognitive tests?
What must you consider for those tests?
MMSE.
MoCA- remember for the pt, it feels like the IMPOSSIBLE MoCA you did in tutorial.
Addenbrooks cognitive examination (more memory based). Look at what component of the test they failed at in order to help determine type of dementia. Overral score is irrelevant
These test have limitations:
- Some questions are too required to know current events
- Some questions require numeracy skills which pts may not have wihtout dememtia anyway
Why do bloods for dementia?
- to see if there are other causes of impaired cognition
- see if there are reversible causes
- rarer causes
What does progression of Alzheimer’s look like on MRI?
As disease progresses , these occur:
> narrow gyri
> wider sulci
> dilated ventricles
> mediotemporal volume loss
> hippocampal volume loss (amnestic presentation)
> space replaced with CSF
How do we use PET scan in dementia?
- amyloid PET scans
- in vivo amyloid imaging corresponds to post mortem slides
- contrast lights up amyloid proteins in the brain
What diagnoses might be made after investigation?
- Alzheimer’s
- Vascular
- Lewy bodies
- FTD
- Depression
- Delirium
- Mixture
- None
What are some management options for dementia?
- acetylcholinesterase inhibitors
- watch and wait
- treating behavioural/psychological symptoms (anti depressants, anti psychotics)
- occupational therapy/ social services
- specialist therapy
What must always be considered with cognitive impairment?
- 3 Ds
- Delirium vs dementia vs depression
- dementias and atypical variants
What are the presentations of Dementia of Lewy bodies?
- Cognitive impairment before/within 1 year of Parkinsonian symptoms
- visual hallucinations
- fluctuating cognition
- REM sleep disorder
Movements affected (gait and balance affected)
what are the presentations of FTD, Alzheimers AND Vascular dementia
Alzheimer’s
- subtle
- insidious
- classic head-turning sign during history
- amnestic/non-amnestic presentation
Vascular dementia
- related to cerebrovascular disease
- classical step-wise deterioration + multiple infarcts.
Frontotemporal dementia
- behaviour variant FTD
- semantic dementia
- progressive non-fluent aphasia
Rapidly progressing dementia
Mixed pathology is normal
Risk factor for dementia
- age
- mid life obesity
- genetic
- brain trauma
- infection or systemic inflammation
- reduced physical activity
Lewy bodies:
what imaging could you use and what would be the result of it?
MRI:
- Preserved hippocampal volume and median temporal volume
SPECT imaging:
- LESS dopamine transporters seen in caudate and putamen
FTD
what would you see in MRI imaging
Perisylvian fissure loss
Temporal lobe volume loss
what are the RARE causes of dementia?
- Progressive supranuclear palsy
- Huntington’s disease
- Multiple system atrophy
- Mitochondrial encephalopathies
- Corticobasal degeneration
Outline the formation of lewy bodies.
Draw it
Start from a synuclein monomer all the way to Lewy bodies
Compare CSF of amyloid plaques and tau for AD
AmyLoid CSF IS Low
Tau is HIGH (TOWER)
How does Amyloid and Tau differ in how to migrate around the brain?
Amyloid eventually migrates towards the Brainstem
Tau starts in brainstem and migrate from frontal cortex to occipital
