PSYCHIATRY Flashcards
define dementia
irreversible, progressive decline and impairment of more than one aspect of higher brain function (conc, memory, language, personality, emotion)
epidemiology of dementia (4)
- rare <65
- alzheimer’s most common, vasc second most
- alzheimer’s more common in F, vasc and mixed more common in M
- fronto-temporal most common in <65s
what are the 4 causes/classifications of dementia?
- Alzheimer’s
- Frontotemporal
- Lewy body
- Vascular
outline the pathophysiology of Alzheimer’s (5)
- extracellular deposition of beta-amyloid plaques
- intracellular deposition of neurofibrillary tangles (NFT)
- leads to reduction in info transmission and brain cell death
- cerebral cortex degeneration with cortical atrophy
- also loss of ACh
outline the pathophysiology of the non-Alzheimer’s dementia causes
- frontotemporal - atrophy of frontal and temporal lobes
- lewy body - deposition of lewy bodies (abnormal protein) in brain stem and neocortex, deficit of ACh and dopamine (parkinsonism)
- vascular - brain damage due to cerebrovasc infarcts e.g. major stroke/multiple small strokes. most affected = white matter of cerebral hemispheres, grey nuclei, thalamus and striatum
risk factors for dementia
AD - old age, Fhx, down’s syndrome
vasc - old age, obesity, HTN, smoking
frontotemporal - genetic mutation
signs and symptoms of AD
- GRADUAL
- most common = short term memory loss (facts, general knowledge, language use, nominal dysphagia)
- disorientation
- getting lost
- decline in ADLs
what is nominal dysphagia and who does it commonly present in?
the inability to recall names of people/objects. seen in AD
signs and symptoms of vascular dementia
- STEPWISE PROGRESSION (stable sx then sudden severity increase)
- vascular pathology hx e.g. stroke, raised BP, focal CNS signs
- cognitive impairment subacutely/acutely following vasc event
- mood disturbance e.g. psychosis, delusions, hallucinations (later stages)
signs and symptoms of lewy body dementia
- GRADUAL
- probs with complex cog actions/multitasking
- visual hallucinations
- Parkinson-like sx
- sleep disorder
signs and symptoms of frontotemporal dementia
- RAPID progression
- peak in 50s-60s
- behavioural/personality change
- loss of language fluency/comprehension
how is dementia investigated in primary and secondary care?
primary - blood screen (exclude reversible causes)
secondary - neuroimaging/structural imaging
what are some neuroimaging techniques that can be used to diagnose dementia? what are they helpful for?
1) CT - rule out lesions/other pathology
2) MRI - shows atrophy/lesions
3) DaTSCAN - dopamine imaging
neuroimaging findings in Alzheimer’s
CT - may exclude space-occupying lesions etc
MRI - generalised atrophy
neuroimaging findings in vascular dementia
CT/MRI - cerebrovascular lesion/s
neuroimaging findings in lewy body dementia
CT - abnormal
MRI - general cortical atrophy
DaTSCAN - reduced dopamine
neuroimaging findings in frontotemporal dementia
what is it often chracterised by?
MRI/CT - focal atrophy in frontal and/or anterior temporal lobes. often characterised by left-right symmetry
ddx for dementia
- delirium
- HIV-related cog impairment
- Creutzfedlt-Jakob disease
- hydrocephalus
- depression
- mild cog impairment (MCI)
how do you manage AD?
EARLY - anticholinesterase inhibitors e.g. donepezil, rivastigmine
LATER - NMDA inhibitors e.g. memantine
how do acetylcholinesterase inhibitors e.g. donepezil help manage AD?
block breakdown of ACh > increase ACh in synapse > increases synaptic transmission of ACh where it’s reduced
how do NMDA inhibitors (e.g. memantine) help manage AD?
glutamate excitotoxicity is associated with delayed evolving neurodegeneration… NDMA inhibitors blocks NMDA receptors when too active > stops excessive glutamate production > slows disease progression
how is vascular dementia managed?
- treat atherosclerosis
- lifestyle modifications e.g. smoking, diet
- antiplatelets (aspirin)
- statins (atorvastatin)
- antihypertensives
how is lewy body dementia managed?
- donepezil/rivastigmine (increase ACh)
- psychotic sx - antipsychotics e.g. risperidone
- sleep probs - SSRIs
- motor sx - carbidopa/levodopa
how is frontotemporal dementia managed?
no specific tx :( can use SSRIs for behavioural sx