Dementia Flashcards
What is the definition of dementia?
a progressive and largely irreversible syndrome that is characterised by a widespread impairment of mental function
sufficiently severe to impair social and occupational functioning
What care needs are implicated in dementia?
dementia is associated with complex needs and high levels of dependency and morbidity
care needs often challenge the skills and capacity of carers and available services
What are the 6 types of neurodegenerative dementia?
Which is the most common and least common?
most common - Alzheimer’s disease
- vascular dementia
- mixed dementia
- lewy body disease
- fronto-temporal dementia
least common - Parkinson’s dementia
In which 3 ways can dementia be classified?
- site in the brain
- age
- pathology
What kind of symptoms are produced from disease of the frontal lobes?
it produces abnormalities in several behavioural domains
abnormality leads to impaired:
- judgement
- abstract reasoning
- strategic planning
- emotional restraint
- control of appetite and continence
What does disease of the medial temporal lobe, hippocampus, amygdala and limbic system lead to?
disorders of memory and hallucinations
What are the symptoms of disorders of the temporal neocortex?
receptive dysphasia and automatisms
What is receptive dysphasia and expressive dysphasia?
receptive dysphasia:
- difficulty in comprehension and understanding
- can speak words fluently, but they do not make sense
expressive dysphasia:
- difficulty putting words together to make meaning
- comprehension is intact
What symptoms arise due to disorders of the occipital lobe?
failure of the visual and sensory systems
What symptoms arise from disease of the parietal lobe?
Why do they occur?
impairment of visuospatial skills and integration of sensory inputs
this leads to sensory agnosias and apraxias
What is meant by an automatism?
an action that is performed unconsciously or involuntarily
What are the 4 categories of classification of dementia based on site?
- anterior
- posterior
- subcortical
- cortical
What are the symptoms of a condition affecting the anterior region?
What are examples of conditions which arise?
frontal premotor cortex
- behavioural changes / loss of inhibition
- antisocial behaviour
- facile and irresponsible
seen in normal pressure hydrocephalus, Huntington’s chorea and metabolic disease
What symptoms arise from a problem in the posterior region?
What condition results from this?
parietal and temporal lobes
- disturbance of cognitive function (memory & language) without marked changes in behaviour
seen in Alzheimer’s disease
What are the symptoms of a problem in the subcortial site?
What conditions results from this?
- apathetic
- forgetful and slow with poor ability to use knowledge
- associated with other neurological signs and movement disorders
seen in Parkinson’s disease and AIDS dementia complex
What are the symptoms associated with a problem in the cortical region?
higher cortical abnormalities including:
- dysphasia
- agnosia
- apraxia
this is seen in Alzheimer’s disease
What is meant by agnosia and apraxia?
agnosia:
- inability to interpret sensations and recognise things
apraxia:
- individual has difficulty with the motor planning to perform tasks or movements when asked
What is meant by young onset dementia?
a young onset age is < 65 years
it is not always memory that is affected
this may be genetic or metabolic
What types of dementia are present in people aged above and below 65?
age above 65:
- alzheimer’s
- vascular
- lewy body
age less than 65:
- alzheimer’s
- vascular
- fronto-temporal
What are the three categories in the molecular-genetic classification of neurodegenerative diseases?
tauopathies:
- characterised by neuronal and/or glial inclusions composed of the microtubule-binding protein, tau
synucleinopathies:
- characterised by abnormal accumulation of aggregates of alpha-synuclein protein in neurones, nerve fibres or glial cells
ubiquinopathies:
What are examples of tauopathies?
- FTD and FTDP-17
- progressive supranuclear palsy (PSP)
- corticobasal degeneration
- Alzheimer’s disease
What are examples of synucleinopathies?
- parkinson’s disease
- dementia with lewy bodies
- multiple system atrophy (MSA)
What are examples of ubiquinopathies?
- motor neurone disease (MND) and MND / dementia
- semantic dementia
What steps are required in the diagnosis of dementia?
- history - GP, memory clinic, neurologist, psychiatrist
- examination
What type of information is crucial when diagnosing dementia?
collateral information (from other people)
time-scale is also important to identify whether it is a rapidly progressive dementia
What are the 2 stages involved in cognitive assessment for dementia?
screening tests:
- MMSE
- ACE-III
- MoCA
neuropsychological assessment:
- objective vs subjective deficit
- how many cognitive domains are affected
- which cognitive domains are affected
What additional tests may be performed when diagnosing dementia?
- blood tests
- structural brain imaging (CT, MRI)
- functional brain imaging (PET, DaT)
- lumbar puncture (biomarkers)
- genetic blood tests
What is the 2 main features that are affected in Alzheimer’s disease?
episodic memory:
- patients are forgetful and repetitively ask the same questions
orientation:
- patients get lost in familiar places
What is meant by episodic memory?
the memory of every day events such as:
- times
- location geography
- associated emotions
- who, what, where, when, why knowledge
that can be explicitly stated or conjured
it is a collection of past personal experiences that occurred at a particular time and place
How does a patient with Alzheimer’s present initially?
How does this change with disease progression?
- in early stages the personality is unchanged and they maintain a good social facade
- the patient lacks insight and head-turning sign is present
- there are eventually more widespread deficits
What is meant by head-turning sign in Alzheimer’s disease?
patients who turn their head toward their caregiver for assistance or cues to help them answer questions are more likely to have Alzheimer’s dementia
What are useful questions to ask patients with Alzheimer’s disease?
- how did you get here?
- what did you do this morning?
- what has been happening in the news lately?
What investigations are performed in Alzheimer’s disease and what are the expected results?
cognitive assessment
examination:
- may have myoclonus or UMN signs
CT/MRI brain scan:
- medial temporal lobe atrophy
FDG-PET scan:
- posterior hypometabolism
CSF biomarkers:
- raised tau
- low a-beta
What is meant by myoclonus?
spasmodic jerky contraction of groups of muscles
What is posterior cortical atrophy?
What causes the symptoms?
a form of dementia that is usually considered an atypical variant of Alzheimer’s disease
it causes atrophy of the posterior part of the cerebral cortex
this results in decline in visuo-spatial processing skills with relatively intact memory
What are some of the symptoms and signs of posterior cortical atrophy?
- vague hemianopia - tend to get lost whilst reading
- reverse size phenomenon - small print is easier to read than large
- cannot judge distances so problems with driving / parking
- difficultly identifying a static object (can still catch a ball)
- difficulty reading fragmented letters
- visual crowding (easier to read letters when they are spaced out)
- light sensitivity and distortion - difficulty with glass / mirror surfaces and prolonged colour after-images
What is hemianopia?
blindness over half the field of vision
What is fronto-temporal dementia?
What are the typical symptoms and areas affected?
a group of non-Alzheimer’s neurodegenerative disorders
memory is intact but language, behaviour and personality are affected
When is the typical onset of fronto-temporal dementia?
onset is in middle life (50-65 years)
up to 50% of cases are familial (consider genetic testing)
there are overlap syndromes (motor neurone disease, parkinsonism, etc.)
What are the 4 subtypes of frontal-temporal dementia?
- behavioural
- semantic
- progressive non-fluent aphasia
- logopenic aphasia
What are the features of behavioural FTLD?
- disinhibited, socially inappropriate, apathy, loss of insight
- sweet tooth
- repetitive behaviours
- executive dysfunction
What are the features of semantic FTLD?
- fluent but empty speech
- anomia - inability to recall names of everyday objects
- impaired word comprehension
- surface dyslexia
What are the features of progressive non-fluent aphasia?
- effortful non-fluent speech
- phonemic errors
- articulation
- orofacial apraxia
- insight is retained
What is orofacial apraxia?
a loss of voluntary control of facial, lingual, pharyngeal and masticatory muscles in the presence of preserved reflexive and automatic function of the same muscle
What are the features of logopenic aphasia?
- hesitant by grammatically correct speech
- impaired phrase repetition
what are the 3 main features of progressive non-fluent aphasia?
- effortful non-fluent speech
- phonemic errors
- orofacial apraxia (tested by asking the patient to cough or yawn)
What are the 3 main features of semantic dementia?
- fluent but empty speech
- impaired word comprehension
- surface dyslexia
patient may have trouble finding names for people and objects and make spelling mistakes
what is meant by surface dyslexia?
a disorder characterised by the inability to read words with “irregular” or exceptional print-to-sound correspondences
e.g. “pint” or “soot”
How would someone with behavioural variant dementia present?
- disinhibited
- impulsive
- apathetic
- compulsive overeating
- executive dysfunction
What are the stages involved in investigating dementia?
- history
- examination
- blood tests
- imaging
What are “treatable” conditions that result from dementia?
- depression
- iatrogenic (anticholinergics, sedatives, narcotics, H2 blockers, multiple meds)
- hypothyroidism
- B12 deficiency
- neurosyphylis
- HIV
- normal pressure hydrocephalus
- subdural haematoma
- encephalitis
What is normal pressure hydrocephalus a triad of?
1. dementia
2. gait disturbance
3. urinary incontinence
occurring in conjunction with hydrocephalus and normal CSF pressure
What are the 2 different types of normal pressure hydrocephalus?
- NPH with a preceding cause
e. g. SAH, meningitis, trauma, radiation induced - NPH with no known preceding cause (idiopathic)
What is shown in this image?
normal pressure hydrocephalus
there is an accumulation of CSF that causes the ventricles in the brain to become enlarged
sometimes there is little or no increase in intracranial pressure
What type of condition looks like this?
transmissible spongiform encephalopathies
under a microscope, the affected brain tissue looks like a sponge
What is the median age of death in classic (sporadic) and variant CJD?
classic CJD - 68 years
variant CJD - 28 years
What is the median duration of illness in classic and variant CJD?
classic CJD - 4-5 months
variant CJD - 13-14 months
What are the clinical signs and symptoms in classic and variant CJD?
classic CJD:
- dementia
- early neurologic signs
variant CJD:
- prominent psychiatric / behavioural symptoms
- painful dyesthesiasis
- delayed neurologic signs
What types of test signs are present in sporadic and variant CJD?
classic CJD:
- periodic sharp waves on electroencephalogram often present
variant CJD:
- “pulvinar sign” on MRI present in >75% of cases
- presence of florid plaques on neuropathology present in large numbers
What signs are present in tissue in sporadic and variant CJD?
classic CJD:
- immunohistochemical analysis of brain tissue shows variable accumulation
variant CJD:
- immunohistochemical analysis of brain tissue shows marked accumulation of protease-resistant prion protein
- presence of agent in lymphoid tissue is readily detected
What would be seen in an EEG in CJD?
triphasic waves on repeat testing
What would be seen on an MRI for sporadic CJD?
non-specific changes in the basal ganglia
What would be seen on an MRI for variant CJD?
a characteristic abnormality seen in the posterior thalamic region - pulvinar sign
this is highly sensitive and specific for vCJD
What is corticobasal degeneration?
How does it usually present?
rare progressive neurological disorder characterised by cell loss and deterioration of a specific area of the brain
affected individuals often initially experience motor abnormalities in one limb which eventually spreads to affect all the arms and legs
What are the signs and symptoms of corticobasal degeneration?
- apraxia - difficulty with motor planning to perform tasks when asked
- alien limb - limbs act on their own without conscious control
- balance, co-ordination, parkinsonism / PSP
- speech and cognitive
What would an MRI for corticobasal degeneration show?
What is the underlying pathology?
- asymmetrical atrophy
- usually parietal and basal ganglia
the pathology is tauopathy
What is encephalitis?
What are the 3 main categories?
inflammation of the brain caused by an infection or through the immune system attacking the brain in error
- viral
- autoimmune
- paraneoplastic
What are the viral causes of encephalitis?
herpes simplex virus
seen on MRI and in CSF
What are the autoimmune causes of encephalitis?
antibodies are present in the blood and CSF
this is usually the voltage gated potassium channel antibody (VGKC Ab LE)
What is meant by paraneoplastic causes of encephalitis?
neuronal antibodies are present in the blood, body examination and imaging
What are the symptoms and signs of VGKC Ab limbic encephalitis?
- subacute memory loss
- psychiatric / behavioural disturbance
- seizures - usually partial
- hyponatraemia
What is present in most cases of VGKC Ab limbic encephaltis?
what tumours may be present?
most cases have serum and CSF antibodies to the LGI1 subunit of the K channel
others have CASPR2
thymoma/SCLC and other tumours may be present, but they are not associated
What is the difference in functions of the anterior and posterior aspects of the brain?
the frontal aspect of the brain is involved in executive functions such as motor, planning and strategic thinking
the posterior aspect is involved in perception / integration of sensory stimuli and encoding knowledge
What is the role of the limbic system?
arousal, emotion, motivation, attention and memory
What are the 8 different diseases of dementia?
- alzheimer’s disease
- vascular dementia
- frontotemporal lobar degeneration
- dementia with parkinsonism
- idiopathic parkinson disease
- dementia with lewy body
- corticobasal degeneration
- progressive supranuclear palsy
- normal pressure hydrocephalus
- creutzfeldt-jakob disease
What are the 5 different proteins which may be involved in dementia?
- B-amyloid
- Tau
- a-synuclein
- TDP-43
- ubiquitin
What are the 2 things involved in the general pathology of dementia?
- neurone loss from the hippocampus and cerebral cortex
- accumulation of abnormal proteins
Where do the abnormal proteins seen in dementia accumulate?
B-amyloid is in plaques and amyloid angiopathy
Tau in neurofibrillary tangles
a-synuclein in lewy bodies
ubiquitin in Pick’s bodies
