Dementia & Diagnosis
According to the ICD definition: dementia requires impairment in how many cognitive domains
What must they also interfere with to be attributed to dementia
At least two cognitive domains (e.g. memory, language, or executive function)
They must also be severe enought to interfere with independant ADLs
Which dementia subtype accounts typically starts with episodic memory impairment?
Alzheimer's Disease (~60% of all dementias)
Donepezil belongs to which drug class?
Acytylcholinesterase inhibitor
Analgesia
Areflexia
Which year was the MCA made?
Capacity is assumed unless?
1983
Unless the person lacks capacity
Mrs McCrae becomes disoriented when staying at her daughter's but improved at home. Which cognitive domain is primarily affected?
Visuospatial function and orientation
Which abnormal proteins accumulate in Alzheimer's?
Beta-amyloid plaques (extracellular)
Abnormally phophorylated Tau (Intracellular)
Why do cholinesterase inhibitors commonly cause bradycardia and diarrhoea?
Increased ACh activity stimulates parasympathetic NS
Propofol is classified as which type of anaesthetic agent?
Intravenous general anaesthetic
4 components required to demonstrate capacity
Understand
Retain
Weigh
Communicate
What is the difference between Mild Cognitive Impairment & Dementia
Dementia has a more significant deterioration in cognitive functions (more than one, compared to one or more)
MCI has perservered independence and functioning
A stepwise decline following stroke suggests which dementia subtype?
Vascular Dementia
Why are AChE inhibitors only effective for symptomatic treatment of Alzheimer's and not disease modification?
They increase synaptic ACh to improe neurotransmission but they do not prevent Beta amyloid plaque formation or Tau
Elderly patients with cognitive impairments are higher risk of which acute post-op complication?
Delerium
Which type of LPA would Mrs McCrae have definitely signed in this case?
Personal welfare LPA
LPA - Lasting power of attorney
List 4 reversible conditions that must be ruled out before diagnosisng dementia
Delirium
Depression
B12 deficiency
Hypothyroidism
Subdural Haemmorrage
Normal pressure hyrocephalus
Alcohol related brain damage
What are the four core clinical features of Dementia with Lewy Bodies?
Fluctuating cognition
Complex visual hallucinations
Parkinsonism
REM sleep disorders
When is it used?
Blocks the action of the elevated Glutamate levels on NMDA receptors and a damaging influx of calcium
What are the difference types of neuromuscular blocker?
What do they do?
Give examples of each drugs of each type
Depolarising: suxamethonium
Similar structure to Ach - causes depolarisation leading to fasciculations.Then remains bound so no other transmission takes place but eventually gets broken down by AChE
Non-depolarising: Tubocurarine, Atracurium, Vecuronium, Rocuronium
Prevents neuromuscular transmission by blocking ACh binding to receptors
Three (or more) psychological impacts of living with dementia
Social isolation
Depression/ anxiety
Stigma
Loss of identity
Family strain
What could GP and a memory clinic use to:
1. Rule out reversible causes
2. Identify dementia subtype
Try and be specific
Blood tests: Alz: Extracellular plaques, Intracellular tangles. Lewy body: Lewy bodies.
CT/ MRI the brain
Detailed history + collateral history
Cognitive testing
What dementia subtype is this?
What is the main risk factor?
Name a couple proteins that contribute to its pathology
Frontotemporal dementia
More genetic, 1/3 Autosomal dominant, can now test for some of the genes
Can have abnormal Tau or TDP-43, FUS, UPS
WHy are AChE inhibitors useful in Alzheimer's but not typically indicated in vascular dementia
ALzheimer's: there is a degeneration of cholinergic neurons and reduced ACh transmission
But in vascular dementia, pathology is because there is cerebral ischaemia, rather than cholinergic degeneration - so increased ACh does not address the underlying mechanism
What are the 3 stages of Anaesthesia?
What are the 3 types of drugs used for GA?
What are the characteristics of an ideal IV induction agent?
Induction, maintenance, reversal
Neuromuscular blocking agents, analgesia, anaesthetic agents
Smooth and rapid onset, Rapid recovery, No pain on injection, Minimal side-effects, No toxicity
Based on the case and lecture content, what is the most likely dementia subtype in Mrs McCrae and why?
What would you expect to see if we performed tests
Likely Alzheimer's, maybe vascular (diseased vessels/ stroke)
Clinical Features: Progressive decline, usually starts with episodic memory
Macro: Mesial temporal lobe atrophy, generalised atrophy
Histology: Extracellular plaques, Intracellular tangles
Proteins: β Amyloid, abnormally phosphorylated Tau