Cognitive Neurology Flashcards
Define cognition
The mental action of acquiring knowledge and understanding through thought, experience and senses
Define dementia
The un-doing of the mind - generally progressive and neurodegenerative
What is the criteria for ‘dementia’?
- evidence of a significant decline in at least one domain
+ deficits interfere with independence
+ not explained by another progress/exclusively delirium
Name three acute cognitive disorders
- focal injury
- transient global amnesia
- transient epileptic amnesia
Name three focal injuries that can cause cognitive disorders
Viral encephalitis - memory, behaviour, pyrexic -frontal lobe
Head injury - attention, memory, executive dysfunction - subcortical or frontal lobe
Stroke - depends on area
What is transient global amnesia?
Abrupt onset antegrade amnesia - difficulty laying down new memories but preserved knowledge of self
Who is usually affected by transient global amnesia?
> 50 years old usually in 70s, lasts less than 24 hours but triggers can be change in temperature or emotion
What is transient epileptic amnesia?
Forgetful with repetitive questioning - can carry out complex activities with no recollection of the event
How long does transient epileptic amnesia last?
20 minutes with associated temporal lobe seizures
Name three sub-acute cognitive disorders
- functional impairment
- prion disease
- limbic encephalitis
What is functional impairment?
Everyday forgetfulness impacting on functioning, can lead to a fugue state - usually has fluctuation of symptoms with a mismatch of symptoms and reported function/neurodegenerative disorders
What is the most common prion disease?
Creutzfeldt Jakob Disease
Describe the pathology of prion disease
Change of prion protein in the brain, misfolded protein cannot be broken down so builds up leading to neurodegeneration
What are the four types of prion disease?
- sporadic
- variant
- iatrogenic
- genetic
Describe sporadic prion disease
60 years old, rapid onset dementia with neurological signs, myoclonus. 4 month duration.
Describe variant prion disease
20 years old, painful sensory disturbance and neuropsychiatric decline. 14 months duration due to exposure to BSE (mad cow disease) or contaminated blood
Describe iatrogenic prion disease
30 years old, cerebellar/visual onset with multifocal neurological decline. <2 years duration occurs due to CJD infection from human growth hormone or dura mater from infected cadavers
Describe genetic prion disease
Can present at any age, mutation in the gene that produces prion protein has a variable duration. Associated with fatal familial insomnia
How is prion disease diagnosed?
EEG, MRI, biomarkers - all will show spongiform changes
What is limbic encephalitis?
Inflammatory autoimmune disease
- short term deficits
- seizures
- behavioural changes
What antibodies can be involved in limbic encephalitis?
Cell surface - VGKC
Intraneuronal - anti HU
What can cause limbic encephalitis and how is it treated?
Paraneoplastic syndrome - treat tumour
Autoimmune - immunosuppression
What investigations are done in limbic encephalitis?
MRI - changes in temporal lobe
CSF - protein and WCC
Name six gradual onset disorders
- Alzheimer’s
- Fronto-temporal dementia
- Vascular dementia
- Lewy body dementia
- Parkinson’s disease dementia
- Huntington’s disease
What is the initial symptom usually in Alzheimer’s?
Forgetfulness
Where does degeneration occur in alzheimer’s?
Hippocampus and parietal lobes
What is classed as early onset alzheimers?
<65 years old, often with atypical presentations
Name two atypical presentations of alzheimers
Posterior cortical atrophy - visuospatial disturbance
Primary progressive aphasia - language dominant
How is alzheimer’s investigated?
MRI for atrophy
CSF for increased TAU and decreased amyloid
SPECT/PET reduced metabolism
When does frontotemporal dementia usually present?
<65 years old, early onset
How does frontotemporal dementia present?
- behavioural changes
- primary progressive aphasia
Early frontal features - disinhibition, apathy, compulsive behaviours
What investigations are required in frontotemporal dementia?
MRI - frontal atrophy
SPECT - decreased metabolism
CSF - increased TAU
How can frontotemporal dementia be treated?
Trazadone, antipsychotics, safety management, family support
What is the criteria for vascular dementia diagnosis?
- presence of cerebrovascular disease
2. clear temporal relationship between dementia and vascular disease
What are the two types of vascular dementia?
- subcortical (small vessel disease)
- stroke
How is vascular dementia managed?
Manage risk factors and may need a cholinesterase inhibitor
When does Lewy Body dementia present?
Late onset
What is the criteria for Lewy Body dementia?
- Fluctuating cognition
- Recurrent well formed visual hallucinations
- Presence of extrapyramidal features - 75% (TRAP)
How is lewy body dementia treated?
Small dose levodopa
Cholinesterase inhibitor
What is the difference between Parkinson’s and lewy body dementia?
> 1 year of pre-existing motor symptoms
What age does huntington’s present?
30-50 years old
What are the symptoms for Huntington’s?
Dysexecutive syndrome - frontal lobe type, slowed speed of processing and eventually memory involvement
Mood and personality changes, chorea and psychosis
