Dementias (EL) Flashcards
Define dementia.
Acquired disorder of cognitive function
Progressive cognitive decline of sufficient magnitude to interfere with normal social or occupational functions/usual daily activities
What are the most common causes of dementia in the UK in order?
Alzheimer’s disease > vascular dementia > Lewy Body dementia > frontotemporal dementia
(These conditions may co-exist)
Define Alzheimer’s disease.
Chronic, progressive neurodegenerative disorder characterised by a global, non-reversible impairment in cerebral functioning
What happens in Alzheimer’s disease?
- degeneration of the cerebral cortex, with cortical atrophy and reduction in acetylcholine production
- build-up of APP (amyloid precursor proteins) - due to beta and gamma secretase
Describe the histopathology of Alzheimer’s disease.
Characterised by senile plaques, neurofibrillary tangles, and neuronal loss
Define vascular dementia.
Chronic progressive disease of the brain causing multifaceted impairment of cognitive function
What happens in vascular dementia?
Brain damage due to several incidents of cerebrovascular disease e.g. strokes/TIAs/infarction/small vessel changes/haemorrhage/leukoaraiosis –> loss of brain parenchyma
Affects planning more than memory, motor and mood changes seen early
Define dementia with Lewy bodies.
Neurodegenerative disorder with parkinsonism, progressive cognitive decline, prominent executive dysfunction, behavioural and sleep disturbances, and visuospatial impairment
What happens in dementia with Lewy bodies?
Deposition of abnormal proteins (Lewy bodies) within the brainstem and neocortex
Define frontotemporal dementia.
FTD manifests primarily as disruption in personality and social conduct, or as a primary language disorder
Almost 50% display parkinsonism, a smaller subset may have motor neuron disease
What happens in frontotemporal dementia?
Specific degeneration of frontal and temporal lobes - thought to be caused by pick bodies
What are the main two clinical features of dementia?
- memory impairment
- cognitive impairment
What are the hallmark signs for Alzheimer’s?
Slowly progressive, episodic impairment of memory, insidious onset
What are the hallmark signs of vascular dementia?
Abrupt cognitive decline and stepwise deterioration
What are the hallmark signs of dementia with Lewy bodies? (4)
- steady decline
- fluctuating cognition / consciousness
- recurrent visual hallucinations
- parkinsonian motor disorders
What are the hallmark signs of frontotemporal dementia? (3)
- early changes in personality (e.g. impulsivity, aggressiveness)
- often has Fx
- earlier age of onset around 45-65 years, peak prevalence in 7th decade
What are the key diagnostic factors of Alzheimer’s?
- memory loss
- disorientation
- nominal dysphasia
- misplacing items/getting lost
- apathy
- decline in ADLs
- personality change
- unremarkable initial physical examination
What are some risk factors for Alzheimer’s?
- advanced age
- family history
- genetics
- Down’s syndrome
- cerebrovascular disease
- lifestyle factors and medications
- less than secondary school education
What are the key diagnostic factors for vascular dementia?
- history of stroke
- difficulty solving problems
- apathy
- disinhibition
- slowed processing of information
- poor attention
- retrieval memory deficit
- frontal release reflexes
What are some risk factors for vascular dementia?
- age >60 years
- obesity
- hypertension
- cigarette smoking
What are some key diagnostic factors for dementia with Lewy bodies?
- fluctuations (cognition, attention, arousal)
- visual hallucinations
- motor symptoms (parkinsonian)
- REM sleep behavioural disturbance
What are some risk factors for dementia with Lewy bodies?
- older age
- (familial occurrence - weak)
What are some key diagnostic factors for frontotemporal dementia?
- coarsening of personality, social behaviour and habits
- progressive loss of language fluency/comprehension
- development of memory impairment, disorientation or apraxias
- progressive self-neglect and abandonment of work, activities, and social contacts
What are some risk factors for frontotemporal dementia?
- mutations in MAPT gene
- mutations in GRN gene
- mutations in C9orf72 gene
- (traumatic brain injury - weak)
