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)
What cognitive assessment do we do for dementia?
Mini Mental State Exam (MMSE)
<24 = dementia
What do the scores mean on the MMSE for dementia?
- 0-17: severe cognitive impairment
- 18-23: mild cognitive impairment
- 24-30: no cognitive impairment
What screen can we do in primary care for dementia?
Blood screen to exclude reversible causes i.e. FBC, U&E, LFTs, calcium, glucose, TFTs (hypothyroidism), vitamin B12 and folate levels
(Neuroimaging then done in secondary care)
What imaging can we do for dementia?
Neuroimaging in secondary care i.e. CT/MRI/PET
What are the 1st line investigations done for Alzheimer’s?
- bedside cognitive testing (MMSE)
- FBC
- metabolic panel
- serum TSH
- serum vitamin B12
- urine drug screen
- CT
- MRI
What are the 1st line investigations done for vascular dementia?
- FBC
- ESR
- BGC
- renal and liver function tests
- vitamin B12
- folate
- thyroid function
- CT / MRI brain
- ECG
What are the 1st line investigations done for dementia with Lewy bodies?
- SPECT (DATscan)
- serum TSH
- serum vitamin B12
- CT head
- MRI head
What are the 1st line investigations done for frontotemporal dementia?
- formal cognitive testing (MMSE)
- brain MRI / CT
- FBC
- serum CRP
- TSH & T4
- metabolic panel
- serum urea
- serum creatinine
- LFTs
- B12 and folate
- syphilis serology
- HIV testng
- serum enzyme-linked immunosorbent assay
What would we see on neuroimaging in the different types of dementia?
- Alzheimer’s: cortical and hippocampal atrophy
- vascular: lacunar infarcts (white areas on MRI)
- frontotemporal: atrophy in frontal and temporal lobes
What would we see on neuroimaging in Alzheimer’s?
Cortical and hippocampal atrophy
What would we see on neuroimaging in vascular dementia?
Lacunar infarcts (white areas on MRI)
What would we see on neuroimaging in frontotemporal dementia?
Atrophy in frontal and temporal lobes
What is the 1st line treatment for mild-moderate Alzheimer’s?
- supportive treatment
- PLUS environmental control measures
- PLUS cholinesterase inhibitors (donepezil, rivastigmine if hallucinations, galantamine)
- CONSIDER management of depression / dementia-related psychosis / insomnia / other behavioural and psychological symptoms
What is the 2nd line treatment for Alzheimer’s (if cholinesterase inhibitors contraindicated/not tolerated/ineffective) OR 1st line for severe Alzheimer’s?
Switch to or add memantine (NMDA receptor antagonist, leading to decreased glutamate-induced excitotoxicity)
What is a contraindication for cholinesterase inhibitors?
Prolonged QT interval
What is the 1st line treatment for vascular dementia?
- antiplatelet therapy (aspirin/clopidogrel)
- PLUS lifestyle modification
- PLUS supportive care
What is the 1st line treatment for dementia with Lewy bodies?
- supportive care
- PLUS cholinesterase inhibitor (e.g. donepezil) or memantine
- CONSIDER non-pharmacological and behavioural interventions
What drug do we avoid in patients with Lewy body dementia?
Antipsychotics - may cause irreversible parkinsonism
What is the 1st line treatment for patients with frontotemporal dementia?
Supportive care
What non-pharmacological treatments are there for dementia?
- cognitive stimulation therapy to improve memory and problem-solving skills
- cognitive rehabilitation
