Dementia Flashcards
What is dementia
An acquired and persistent generalised disturbance of higher mental functions in an otherwise fully alert person
Neurodegenerative condition - loss of neurons
Is dementia always pathological?
YES
It is not part of the ageing process
What are the primary dementias
Alzheimer’s
Lewy body dementia
Pick’s disease - fronto-temporal dementia
Huntington’s
What are the secondary dementias
Multi-infarct - vascular Infection - HIV, syphilis Trauma Drugs and toxins - alcohol Vitamin deficiencies - thiamine SOL's and paraneoplastic
What is the most common types of dementia
Alzheimer’s
Describe the trends in prevalence of Alzheimer’s
Get more common with age
Later the onset, the more rapid and severe the changed tend to be
Is Alzheimer’s genetic
Yes and No
Usually sporadic
Some cases are familial - APP, Presenilin 1&2
Increased risk in Down’s syndrome
Why is Alzheimer’s more common in trisomy 21
The amyloid precursor protein gene is found on chromosome 21
This is implicated in the disease and leads to early onset
How does Alzheimer’s present
Insidious impairment of higher intellectual function, with alterations in mood and behaviour
General forgetfulness is common initially
Also have visuospatial difficulties
Later – progressive disorientation, memory loss and aphasia indicate severe cortical dysfunction
Does Alzheimer’s usually cause death
It is usually due to a secondary cause such as bronchopneumonia
What is the macroscopic pathology of Alzheimer’s
Cortical atrophy
Widening of the sulci
Narrowing of the gyri
Compensatory dilation of ventricles
Which areas of the brain are usually spared in Alzheimer’s
Occipital lobe
Brainstem
Cerebellum
What are the microscopic features of Alzheimer’s
Neuronal loss - atrophy and gliosis
Disruption of the cholinergic pathways
Neurofibrillary tangles - insoluble tau protein which disrupts neurons
Neuritic plaques - amyloid plaques extracellularly
Amyloid angiopathy
What is amyloid angiopathy
Extracellular accumulation of amyloid protein
Disrupts the BBB - oedema, local hypoxia and serum leaking
How does Lewy body dementia present
Progressive dementia alongside visual hallucinations and fluctuating attention
Memory is affected later
Fluctuation in severity of condition on a day‐to‐day basis
Features of Parkinsonism present at onset, or emerge shortly after
Symmetrical tremor
Visual spatial defect
Does everyone with Parkinson’s get Lewy body dementia
NOPE
However, everyone with Lewy body dementia will have features of parkinsonism
What are the features of Parkinsonism
Loss of facial expression Stooping Shuffling gait Slow initiation of movement Pill rolling tremor
What are the pathological features of Lewy body dementia
Degeneration of the substantia nigra
Disrupts the cholinergic and dopaminergic pathway
Will appear pale - loss of pigmented neurons
Reactive gliosis and accumulation of microglia
Lewy bodies present
How is Huntington’s inherited
Autosomal dominant
Mutation on the Huntington’s gene causes CAG repeats
Disease occurs when more than 35 repeats
Produces a neurodegenerative protein
What are the clinical features of Huntington’s
Triad of emotional, cognitive and motor disturbance
Chorea (dance‐like movements), myoclonus, clumsiness, slurred speech, depression, irritability and apathy.
Develop dementia later
Huntington’s has a long disease process - true or false
True
Often around 15 years from symptoms starting until death
Describe the pathology seen in Huntington’ s
Atrophy of the basal ganglia (caudate nucleus and putamen)
Cortical atrophy occurs later and corresponds to the onset of dementia
What is the other name for Pick’s disease
Fronto-temporal dementia
How does Pick’s disease/FTD present
Personality and behavioural change - including social deterioration
Speech and communication problems
Impairment of intellect, memory and language
Changes in eating habits
Reduced attention span
Fast loss of insight - no idea their behaviour is abnormal
Describe the disease pattern of Pick’s disease/FTD
Starts in middle life (50-60) which is younger than most dementias
Rapidly progressing - lasts between 2-10 years
Describe the underlying pathology of Pick’s disease
Extreme atrophy of the frontal lobes and later in the temporal lobes
Tau protein problem, aggregate within neuronal cells which causes death and neurodegeneration
Neuronal loss and gliosis
Will see Picks cells and Picks bodies on histology
What causes multi-infarct dementia
Successive, multiple cerebral infarctions cause increasingly larger areas of cell death and damage
Damage is cumulative and caused by hypoxia as a result of infarcts
Who gets multi-infarct dementia
More common in men
Usually seen after age 60
Also seen in younger hypertensives
Post-stroke
What characterises multi-infarct dementia
Insight
Sufferers aware of their mental deficits and are prone to depression and anxiety.
How does mutli-infarct dementia present
Similar to Alzheimer’s symptom wise
Abrupt onset with a stepwise progression
Progresses slowly
History of hypertension or stroke (evidence on CT)
Patient has insight into deficits
Depression is common
What are the risk factors for multi-infarct dementia
Same as CVD
Hypertension, smoking etc
Previous stroke
Describe the morphological appearance of multi-infarct dementia
See large vessel infarcts scattered through the hemispheres
May have smaller lacunar infarcts
What is cognition
The mental action of acquiring knowledge and understanding through thought, experience, and the senses
Split into: Memory
Attention (ability to be alert enough to take info in)
Social functioning; how to evaluate and reason
Language: ability to produce, and understand language
Executive function; problem solving, decision making
What are the criteria for a diagnosis of dementia
Evidence of significant cognitive decline in at least 1 domain
Must interfere with everyday activities and independence
Must not be diagnosable as something else
Is forgetfulness always a sign of dementia
NO
Everyone has days of poor cognitive function such as forgetting names
What is the greatest risk factor for dementia
Ageing
Most occur above the age of 65
List acute cognitive disorders
Brain insults/injury
Transient global ischaemia
Transient epileptic amnesia
Describe the effects of brain insults
Deficits depend on the area of brain affected
Includes:
Viral encephalitis (memory, behaviour change, and language)
Head injury (memory, executive dysfunction)
Stroke
How does transient global amnesia
Abrupt onset More commonly anterograde amnesia Preserved knowledge of self - name, age etc Transient - 4-6hours Generally a once off
What triggers transient global amnesia
Emotion
Changes in temperature
Uncertain pathophysiology
Who gets transient global ischaemia
The over 50s
usually in 70s
What is anterograde amnesia
Can’t lay down new memories
What is retrograde amnesia
Cannot remember things from the past
What are the clinical features of transient epileptic amnesia
Forgetful / repetitive questioning
Can carry out complex activities with no recollection of events
Short lived (20 – 30 minutes)
Recurrent problem
What is transient epileptic amnesia associated with
Temporal lobe seizures
How can you treat transient epileptic amnesia
Should respond to anti-epileptic medication
List some common sub-acute cognitive disorders
Functional disorders Mood disorders Metabolic - B12, thyroid etc Inflammatory - encephalitis Toxins - alcohol CJD Infection - HIV etc
What is functional/subjective cognitive impairment
Everyday forgetfulness that starts to impact upon ability to function
Losing keys, forgetting names etc
Fluctuating symptoms - good and bad days
Mismatch between symptoms + reported function (feel they should remember more than they do, even if normal and no one has reported concern)
How can you treat functional/subjective impairment
Exclude a mood disorder and Alzheimer’s
Neuropsychology
What is the most common human prion disease
Creutzfeldt-Jakob Disease
Still very rare
Leads to neurodegenerative conditions due to prion abnormality in the brain
What are the 4 types of CJD
Sporadic
Variant - from BSE in cows
Iatrogenic
Genetic
What are the symptoms of sporadic CJD
Rapid onset dementia, neurological signs and myoclonus
Lasts around 4 months
Often fatal
What are the symptoms of variant CJD
Painful sensory disturbance
Neuropsychiatric decline - personality changes
Duration of around 14 months before death
How does iatrogenic CJD present
Cerebellar or visual onset
Multifocal neurological decline
Illness duration of less than 2 years before death
How does genetic CJD present
Similar to sporadic
May have ataxia or insomnia
Variable duration but usually less than 2 years
How do you diagnose CJD
EEG and MRI
Gold standard is a brain biopsy - becomes spongiform
What is posterior cortical atrophy
Unusual form of Alzheimer’s
Part of the visual field deteriorates
Cannot recognise faces and has difficulty going down stairs
Memory symptoms appear later
What is progressive primary aphasia
Unusual for of Alzheimer’s
Can’t name something correctly, can’t repeat something back, very difficult to talk
memory and behavioural symptoms come later
What investigations would you do for Alzheimer’s
MRI - shows atrophy
SPECT - shows decreases in metabolism
CSF will show reduced amyloid
How can you treat Alzheimer’s
Address vascular risk factors - reduced risk of progression
ACh boosting treatment - cholinesterase inhibitors or NMDA blockers
How would frontotemporal dementia appear on investigations
MRI would show atrophy of frontotemporal lobes (later sign)
SPECT would show decreased metabolism in the frontotemporal areas
CSF will have increased tau
How can you manage frontotemporal dementia
Trials of anti-psychotics to help behavioural symptoms
SSRIs may help behaviour
Mainly safety management - controlled access to food, money, internet
Support for family - power of attorney
How can you manage vascular dementia
Reduce CVS risk factors- stop smoking, reduce cholesterol,
Give cholesterase inhibitors if clear also have AD
How can you investigate Lewy body dementia
DaT scan - dopamine transporter imaging
Will show reduced uptake in the basal ganglia
Will look like dots instead of commas
How can you treat Lewy body dementia
Small dose of levodopa - will help motor but not cognitive symptoms
Community and nursing support
What generally causes dementias
Neurodegenerative proteinopathies
What is Parkinson’s disease dementia
Dementia that present in someone who already has Parkinson’s
The dementia will present over one year after the appearance of Parkinson’s symptoms
How does dementia present in Huntington’s
Early onset dementia (30-50)
Slow processing
Eventual involvement of memory
Changes in mood and personality
How can you manage Huntington’s
Mood stabilisers
Treat chorea
Specialist Huntington’s nurse
Who do you refer dementia patients to
If over 65 and no additional features - old age psychiatry
If under 65, unusual features or additional neurology - neurology
What tests are found in a dementia blood screen
FBC, LFT and U&E B12 and folate Thyroid function HIV and syphilis Calcium \+/- genetic panel
When is SPECT imaging used
Done if MRI normal but clear cognitive changes
What is the most common type of vascular dementia
Multi-infarct dementia
What comes first in Lewy body dementia - cognitive decline or Parkinsonism
The cognitive decline starts first
Parkinsonism will appear shortly after
What is the issue in cortical dementia
The problem is with storing memories
Alzheimer’s is a type of cortical dementia
What is the issue in subcortical dementia
The problem is with retrieving memories - may remember with a prompt
Lewy body and vascular dementia are in this category
Which drugs increase mortality in Lewy body dementia
Anti-psychotics
What is a REM sleep disorder
Shouting out or purposeful movement when asleep
Seen in Lewy body dementia and Parkinson’s
Which other disease can frontotemporal dementia be seen in
Motor neurone disease
How is memantine used in dementia
Its a glutamate inhibitor used in moderate to severe dementia
May help with behavioural issues
What is the contraindication to using cholinesterase inhibitors
Can slow the heart rate so need to check pulse first
Do an ECG if you suspect bradycardia or heart block
