CASE 5 - Dementia Flashcards
Name 2 categories of the etiology of dementia
Neurodegenerative
Additional causes (e.g. cerebrovascular disease, hypoxia)
Name the most common neurodegenerative cause of dementia
Alzheimer’s
How does dementia usually present clinically?
A spouse or family member brings to attention the memory loss
Which cognitive functions tend to DECLINE with age and which tend to IMPROVE?
IMPROVE: word knowledge
DECLINE: speed of processing, working memory, long-term memory
What is the definition of dementia?
A group of diseases characterised by declines in cognition, function, and behaviour
What is the number one risk factor for dementia?
AGE
What percentage of cases of Alzheimer’s disease are sporadic vs. familial?
SPORADIC: 95%
FAMILIAL: 5%
Describe the characteristics of the EARLY stage of Alzheimer’s disease and how long this usually lasts.
EARLY STAGE: 2-4 years.
(often not noticed by family and friends)
- Frequently forgetting or misplacing items
- Getting lost easily
- Need reminder for daily activities
- Word finding problems
- Repeated questions
- Loss of interest in previously enjoyable activities
Describe the characteristics of the MIDDLE stage of Alzheimer’s disease and how long this usually lasts.
MIDDLE STAGE: 2-10 years.
(usually obvious to family and friends)
- Wandering, disruptive behaviours
- Sundowning
- Require constant supervision
- Persistent and pervasive memory loss
- Delusions
- Disrupted sleep
Describe the characteristics of the LATE stage of Alzheimer’s disease and how long this usually lasts.
LATE STAGE: 1-3 years
- Withdrawn, with extreme mood & behavioural problems
- Cannot speak or understand language
- Bedbound, chair bound, unable to walk
- Cannot recognise even the closest family members
- Brain loses the ability to control the body
- Difficulty swallowing (pneumonia is common)
What is the life expectancy of someone who has been diagnosed with Alzheimer’s disease?
Life expectancy after diagnosis = 3 - 20 years.
Average is 8 years
Name 3 GENETIC MUTATIONS that increase risk of familial Alzheimer’s
Genes affected:
- APP
- Presenilin1 (most common)
- Presenilin2
Name 2 RISK MODIFIER/SUSCEPTIBILITY GENES that increase the risk of developing Alzheimer’s
- ApoE gene: possessing 1 or more copies of ApoE4 markedly increases risk
- A2M gene
https: //www.mayoclinic.org/diseases-conditions/alzheimers-disease/in-depth/alzheimers-genes/art-20046552
Name 5 health conditions/lifestyle factors that are risk factors for Alzheimer’s disease
- Cerebrovascular disease
- Smoking
- Obesity
- HTN
- T2DM
- Traumatic head injury
- Alcohol
Describe the brain changes that occur in late-stage Alzheimer’s disease
BRAIN ATROPHY:
- Enlargement of the ventricles
- Enlargement of sulci
- Shrinkage of cerebral cortex
- Shrinkage of hippocampus
Which ApoE allele puts you most at risk of developing Alzheimer’s disease?
How is this allele inherited?
ApoE on chromosome 19: one copy from your mother, one copy from your father.
If you inherit 2 COPIES of ApoE4, you have a 19-fold increased risk of developing AD compared to someone who inherits 2 copies of ApoE3.
https://www.youtube.com/watch?v=v5gdH_Hydes
Describe the 3 pathophysiological mechanisms that contribute to Alzheimer Disease
- SENILE / NEURITIC PLAQUES: Amyloid Plaques (extracellular / outside neurons)
- NEUROFIBRILLARY TANGLES: Tau tangles (intracellular - tau is a component of microtubules)
- Acetylcholine deficiency
How do beta-amyloid plaques affect brain function?
- Beta-amyloid plaques are STICKY and can form clumps that get between neurons, disruption neuron-neuron signalling
- They may also be pro-inflammatory –> inflammation damages surrounding neurons
- They can deposit in blood vessels and increase the risk of haemorrhage
https: //www.youtube.com/watch?v=v5gdH_Hydes
How do tau tangles disrupt neuronal function? Outline the pathophysiology.
Tau holds together the microtubules found in axons.
- It is thought that beta-amyloid plaques initiate KINASE activation, transferring phosphate to the tau protein.
- Phosphate causes the tau proteins to break away from microtubules and form clumps/tangles
- The phosphorylated tau tangles disrupt neuronal signalling
What is the first feature of Alzheimer Disease?
Memory loss
Outline the DSM-5 criteria for dementia
- Significant cognitive decline in at least one of the following domains:
- Learning and memory
- Language
- Executive function
- Complex attention
- Perceptual-motor
- Social cognition - Cognitive deficits interfere with everyday life, patient becomes dependent on help with complex activities (e.g., paying bills)
- Cognitive deficits do not occur exclusively in the context of a delirium
- Cognitive deficits are not better explained by another mental disorder (e.g., major depression)
What is assessed by the MMSE?
What is the cutoff for dementia?
Degree of cognitive impairment in individuals with suspected dementia
A patient with an MMSE score of <24 is generally considered to have dementia
List the MMSE categories for mild, moderate, and severe dementia
MILD DEMENTIA: 21-24 points
MODERATE DEMENTIA: 10 - 20 points
ADVANCED DEMENTIA: <10 points
Name the 5 components of diagnosing dementia
- Full medical history (including drugs & alcohol)
- History of progressive cognitive decline
- Physical exam
- Investigations
- Validated cognitive assessment tool
How many Australians over the age of 65 have dementia?
1 in 10 Australians over the age of 65 have dementia
Name 5 potentially modifiable risk factors for dementia
Air pollution (including second-hand smoke exposure) Hazardous alcohol consumption Depression Diabetes Poor education Head injury Hearing impairment Hypertension Obesity Physical inactivity Smoking Social isolation.
(identified by a Lancet commission)
Name 5 lifestyle factors that can be protective against dementia
- Regular physical activity
- Smoking cessation
- Remain cognitively and socially active
- Eat a healthy diet
- Protect against head trauma (e.g. wearing a helmet while cycling)
- Reduce alcohol intake
- Prevent hearing loss
- Practice good sleep hygiene
The use of certain drugs in later life may increase dementia risk. Name these 3 drugs
- Antihistamines
- Anticholinergics
- Benzodiazepines
Dementia is diagnosed when…
2 facets
- Cognitive decline affects a person’s ability to function independently
- This decline is not attributable to another reversible cause (e.g. depression)
Some causes of cognitive impairment are reversible and should be excluded before a diagnosis of dementia is made. For each of the following investigations, state what underlying cause is being looked for:
- CBE
- BUN, calcium, creatinine, electrolytes
- LFTs
- TFTs
- BGL
- B12 & folate
- CBE: rule out anaemia and infection
- BUN, calcium, creatinine, electrolytes: rule out metabolic disturbances & organ failure
- LFTs: just see if it’s abnormal lol
- TFTs: rule out hypo/hyperthyroidism
- BGL: rule out hypo/hyperglycaemia
- B12 & folate: rule out deficiency
Patients with dementia symptoms who are at risk of STI should also receive which investigations? Why?
- Syphilis serology
- HIV antibody-antigen testing
Symptoms may be due to neurosyphilis or dementia may be associated with HIV
Many cognitive tests exist to assist with the diagnosis of dementia. How do clinicians choose which test to use?
Choice of test depends on PATIENT FACTORS (e.g. linguistic ability, motor and verbal skills, age, education) and CLINICIAN EXPERIENCE
https://tgldcdp-tg-org-au.proxy.library.adelaide.edu.au/viewTopic?topicfile=dementia&guidelineName=Psychotropic&topicNavigation=navigateTopic#toc_d1e1702
Name 5 dementia subtypes, in order of prevalence
- Alzheimer Disease (50-75%)
- Vascular dementia (20-30%)
- Frontotemporal dementia (up to 10%)
- Dementia with Lewy bodies & Parkinson disease dementia (up to 10%)
> 90% of patients will also experience behavioural and psychological symptoms of dementia (BPSD), in addition to memory loss.
Name 3 examples of BPSD
- Hallucinations
- Delusions (distressing beliefs)
- Agitation
- Depression
- Anxiety
- Apathy
- Disinhibition
- Night-time behaviours (waking up and getting up at night)
Which dementia subtype is most commonly associated with memory impairment EARLY ON in the disease?
Alzheimer dementia
Unless there is a clear diagnosis of mild-moderate dementia, which type of imaging should also be ordered?
Head CT, MRI, or PET scan to exclude other NEUROPATHOLOGIES and also determine dementia SUBTYPE
List the characteristic order of LANGUAGE impairment in Alzheimer Disease
Naming –> comprehension –> fluency