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- Withdrawn, with extreme mood & behavioural problems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
Loss of insight is seen in which dementia subtype?
Frontotemporal dementia
but is also common in AD
How can Alzheimer Disease be differentiated from age-related memory loss on History?
Ageing: INDEPENDENCE is preserved. Episodic and working memory are affected first, with preservation of semantic and procedural memory.
Alzheimer Disease: short-term memory loss and loss of episodic memory.
Familial AD results in _______ onset of the disease and ______ progression.
Familial AD results in EARLIER onset of the disease and RAPID progression.
What is the significance of grasp reflexes in adults?
Signifies frontal lobe damage
The presence of a tremor may suggest which causes of DEMENTIA?
Parkinson Disease
Frontotemporal Dementia
Huntington Disease
Romberg test
.
Describe the Parkinsonian gait
PARKINSONIAN SHUFFLING GAIT
- Feet land flat on the floor, instead of on the heel
- Festation/shuffling (quick, small, involuntary steps forward)
- Retropulsion (quick, small, involuntary steps back)
- Propulsion: forward-learning gait
- Decreased arm swing
Cogwheel rigidity is a feature of which type of dementia?
Describe this sign.
Parkinson disease
Cogwheel rigidity: a tremor inlaid within increased muscle tonus/rigidity. Can manifest BEFORE a tremor.
Name 5 clinical features of vitamin B12 deficiency
- Signs of anaemia (e.g. pallor) and jaundice
- Neuropsychiatric disease (e.g. depression, dementia)
- Glossitis
- Worsening vision
- Loss of autonomic function (impotence, incontinence)
- Neurological deficits: loss of sensation, proprioception, gait abnormalities, spastic paralysis
Which types of memory loss occurs FIRST in AD?
Episodic memory
Short-term memory
What is PARKINSONISM and how does it differ from PARKINSON DISEASE?
Parkinsonism is a clinical SYNDROME presenting with these 4 features:
- Rigidity
- Rest tremor
- Bradykinesia
- Postural instability
Parkinson Disease is a neurodegenerative disease which MOST COMMONLY causes Parkinsonism.
Which neurons are depleted in Parkinson Disease?
Dopaminergic neurons in the substantia nigra of the basal ganglia are depleted in PD
How is Parkinson Disease Dementia (PDD) differentiated from Dementia with Lewy Bodies (DLB)?
Parkinson Disease Dementia = dementia occurs after a well-established history of Parkinsonism for >1 YEAR after the onset of motor symptoms
DEMENTIA w/ LEWY BODIES = dementia usually occurs WITH or BEFORE the development of parkinsonian signs, or no more than a year after onset of motor symptoms
https://www.amboss.com/us/knowledge/Parkinson-plus_syndromes#Z1fbf2126dd4b0d719afbb860d583d62f
Remember that many patients that have Lewy body dementia also show brain changes that are characteristic of AD. The DOMINANT change is the one used to guide diagnosis.
.
Name the 4 cardinal features of Parkinsonism (TRAP)
- Tremors
- Rigidity
- Decrementing bradykinesia (/Akinesia)
- Postural instability
Other than the 4 cardinal features of Parkinsonism, name 2 symptoms from each of the following categories:
- CRANIOFACIAL
- VISUAL
- GAIT
- CRANIOFACIAL: hypomimia, hypophonia, dysphagia
- VISUAL: blurred vision, eyelid opening apraxia
- GAIT: shuffling, freezing, festination
Destruction of the basal ganglia is responsible for many of the symptoms of Parkinson Disease. Explain the reason for this.
The basal ganglia plays an INHIBITORY role in motor movement, working to eliminate antagonistic or unnecessary movement.
When the dopaminergic neurons in the basal ganglia are destroyed, these inhibitory effects cannot be carried out. This results in:
- Increased muscle tone (rigidity)
- Unnecessary/unwanted movements (tremors)
- Slowness in initiating new movement
What is the typical age of onset of Parkinson Disease?
~60 years (though genetic forms tend to manifest earlier)
The preclinical phase of Parkinson Disease can be preceded by which 4 symptoms?
- Anosmia
- Constipation
- Mood disorders (e.g. depression, anxiety, apathy)
- Sleep disturbances (e.g. REM sleep disorder, restless leg syndrome, excessive daytime sleepiness)
How is Parkinson Disease diagnosed?
CLINICALLY
Motor signs in Parkinson Disease are usually distributed…
Unilaterally (but can progress to the contralateral side) & asymmetrically (more pronounced on one side)
What is the froment manoeuvre?
The patient is asked to perform repetitive movements (e.g. tapping their hand) in the contralateral extremity to make subclinical rigidity more pronounced
Describe what you might find on general inspection of a patient with Parkinson Disease
- Stooped posture
- Resting tremor
- Rigidity
- Flexed elbows and wrists
- Hypomimia
Name 3 NON-MOTOR features of Parkinson Disease
- AUTONOMIC SYMPTOMS (postural hypotension, urinary urgency, oily skin, impaired sexual function)
- NEUROPSYCHIATRIC: anxiety, depression, apathy, cognitive deficits
- DISORDERED SLEEP
Other: anosmia, hypomimia
What is the first-line pharmacological management of Parkinson Disease?
LEVODOPA + either BENSERAZIDE or CARBIDOPA
LEVODOPA = dopamine precursor
BENSERAZIDE & CARBIDOPA are peripheral decarboxylase inhibitors that prevent PERIPHERAL conversion of levodopa to dopamine. They do not cross the BBB, so levodopa can still be metabolised to dopamine where it’s needed.
What is MILD COGNITIVE IMPAIRMENT (MCI)?
Mild cognitive impairment is generally accepted as the state prior to developing clinical dementia, where ST memory problems may evolve. 15% of patients with MCI go on to develop Alzheimer Disease.
Give 2 examples of (non-dementia) conditions which can cause MCI.
- Depression (i.e. pseudodementia)
- Vascular disease
Name 2 situations in which CSF biomarkers can be used in dementia diagnosis
When there is clinical suspicion of certain conditions:
- EXCLUSION of certain diseases (e.g. VZV, HSV, HIV syphilis)
- ATYPICAL clinical presentations of AD
Which drug class is used for pharmacological management of Alzheimer disease?
Acetlycholinesterase inhibitors
Name the 3 first-line pharmacological treatments of Alzheimer Disease
When can you consider increasing the dosages?
- Donepezil
- Galantamine
- Rivastigmine (transdermal patch)
Doses can be increased after 4 weeks if the patients are tolerating it well. Adverse effects are dose-dependent, which is why you start with a low dose and slowly increase.
What drug can be added (or used instead of acetylcholinesterase inhibitors) in patients with moderate - severe dementia?
Memantine (NDMA receptor antagonist)
For those with an MMSE of 10-14
What are the adverse effects of acetylcholinesterase inhibitors?
Significant GI effects (NV, diarrhoea, anorexia)
Weight loss, vivid dreams, urinary incontinence, tremor, etc.
Which 3 tests must be performed before commencing acetylcholinesterase inhibitors?
- Weight
- ECG
- Falls risk
Acetylcholinesterase inhibitors can only be prescribed for patients with an MMSE ABOVE…?
10
When and what type of neuroimaging is ordered in dementia?
CT head is ordered for most people
Geriatrician will order an MRI for some
How can you differentiate between someone with mild cognitive impairment (MCI) and early dementia?
Those with only MCI will retain their independence
The ApoE2 gene has what function in Alzheimer Disease?
It is PROTECTIVE
For how long are the Alzheimer drugs beneficial?
6-7 months
Beyond that, there is no benefit. Only adverse effects
Do acetylcholinesterase inhibitors slow the progression of disease?
NO - they only offer symptom improvement
Why is it important for a therapeutic trial of acetylcholinesterase inhibitors to be carried out?
- Not everyone responds to them
- Those who do respond can show clinically-significant improvement
- An MMSE score improvement of 2 or more is required for them to be funded by the PBS
Can a patient continue receiving subsidised acetylcholinesterases beyond the first 6 months?
YES - if they demonstrate a clinically-significant response (MMSE +2 points, or improved quality of life)
The GP must obtain approval by phone and re-assess every 6 months
What is the Montreal Cognitive Assessment (MoCA), and what does it involve?
MoCA = a screening tool that assesses cognitive impairment. Scored /30.
Involves visuospatial function, naming, memory, attention, etc. (the one with the 3 animals)
Describe the Rowland University Dementia Awareness Scale (RUDAS) and its benefits.
Tests visuospatial ability, memory, praxis, language, etc.
Beneficial in patients whose first language is not English (does not rely on linguistic ability as much).
Name 4 cons of the MMSE
- Lacks clinical specificity
- Insensitive to patients with MCI
- Does not take into account things like education level, linguistic ability
- High measurement error limits its ability to document change over time
What is the MOA of donepezil?
Decreases breakdown of acetylcholine, reducing the apparent deficiency of cholinergic NT activity in Alzheimer’s disease.
What is the MOA of memantine?
NDMA antagonist
May reduce glutamate-induced neuronal degradation. Alzheimer’s disease is thought to be associated with excess glutamate.
Do patients with dementia retain the ability to drive?
Most patients with dementia lost the ability to drive within a few years of diagnosis
Name 3 strategies for minimising the impact of cognitive decline on the daily life of a patient with dementia
- Determine and address unmet needs (e.g. organise help w/complex ADLs)
- Deprescribe drugs that could exacerbate cognitive impairment
- Webster pack if needed
- Review driving ability
How can the BPSD of dementia be managed?
- Identify triggers, optimise non-pharm interventions
- Dementia Behaviour Management Advisory Service (DBMAS) has a 24-hour helpline
List 3 non-pharmacological measures of managing dementia
- Healthy lifestyle (E.g. sleep, reduce alcohol, smoking cessation, healthy living, remain cognitively and socially active)
- Plan for the future (ACD, SDM)
- Medications review
What are Lewy bodies?
Aggregates of misfolded alpha-synuclein + other proteins
Lewy bodies are implicated in which types of dementia?
- Lewy body dementia
- Parkinson disease
State 1-2 distinguishing features of each of the following dementia subtypes:
- Vascular dementia
- Dementia with lewy bodies
- Parkinson dementia
- Frontotemporal dementia
- Normal pressure hydrocephalus
- VASCULAR DEMENTIA: may present with abrupt cognitive decline and stepwise deterioration. Asymmetric or focal deficits.
- DLB: Visual hallucinations, parkinsonian motor signs, attention impairment
- PARKINSON DEMENTIA: dementia onset >1 year after motor symptoms,
- FRONTOTEMPORAL DEMENTIA: early changes in personality, apathy
- NORMAL PRESSURE HYDROCEPHALUS: ‘wet, wobbly, whacky’ = urinary incontinence, gait disorder, dementia
Describe the potential CT head findings in someone with Alzheimer disease
- Reduced hippocampal volume
- Enlarged sulci
- Enlarged ventricles
What is an ACAT?
Aged Care Assessment Team
Assesses the needs of older people and makes recommendations for government-funded care and support (e.g. home care packages)
How could you counsel a patient who is resistant to receiving an ACAT?
The ACAT will help ensure that you can stay at home for longer by seeing if we can make your life at home safer and easier
It’s not being used to put you in a nursing home
Driving difficulty is prominent in which of the common types of dementia?
Which functions have been impaired?
Driving difficulty is common in AD and DLB.
Due to impaired executive and visuospatial function.
