L1 Dementia Flashcards
What is dementia a clinical syndrome of?
progressive cognitive decline with impaired social or occupational functioning
what % is prevalence in 80+ compared to 40-65?
20% to 0.1%
name 4 different types of dementa
alzheimers
dementia with Lewy bodies
frontotemporal lobar degeneration
vascular Dementia
what is the most common type in >65 for the 4 types in order
ad
VaD
DLB=other
what are common patterns of cognitive impairment in Alzheimers
episodic, topographical memory
early parietal deficits visuo-perceptual, visuo spatial, calculation, praxis, later global cognitive impairment
what type of dementia are these symptoms in: executive dysfunction, visual hallucinations, parietal lobe deficits/episodic memory
dementia with lewy bodies
what type of dementia commonly shows behavioural/personality changes, executive dysfunction, language specific subtypes?
fronto temporal lobar degeneration
what symptoms are common in vascular dementia
vascular dementia
what does neuroimaging contribute
- exclusion of surgically remediable lesion
- diagnostic positive predictive value
- detection and quantification of change
what is the general framework of understanding dementias
genetic/other risk factors –> abnormal protein deposited in brain –> loss of brain cells (brain atrophy) –> altered neurotransmitter function –> symptoms and signs of the disease
what is the pathogenesis of Alzheimer’s disease following the general framework
- genetics: APP, PS1, PS2, ApoE4
- protein: amyloid plaques, tau positive neurofibrillary tangles
- atrophy - hippocampal atrophy initially then whole brain
- altered neurotransmitter: cholinergic
symptoms: episode memory problems, later global deficits
what happens in quantifying regional atrophy
put scans together, measure if there’s been any change in brain volume then put colour on it
what is a symptom of posterior cortical atrophy
visual perception/spatial
can’t orient themselves in space or put objects down and forget or can’t place things properly
involvement of parietal cortex
what is the framework of Dementia with Lewy bodies
protein: alpha synuclein
brain atrophy: posterior or generalised
altered neurotransmitter: dopaminergic, cholinergic
symptoms: visual hallucinations, cognitive decline, fluctuations, parkinsonism
what are key features of dementia with lewy bodies
visual hallucinations fluctuations in cognition REM sleep disorder parkinsonism relative absence of disproportionate hippocampal atrophy on MRI
what is the pathogenesis of FTLD
genetic: MAPT, progranulin, C9ORF72, CHMP2B, VCP, TBK1
what is the macroscopic pathology of FTLD
- front can be shrivelled
- classically knife-blade frontotemporal atrophy but severity variable
- variable involvement of parietal lobes
- subcortical structures (amygdala, hippocampus, basal ganglia, thalamus frequently involved)
what symptoms are seen in behavioural variant FTLD
loss of texture pain awareness utilisation behaviour grasp reflex rooting reflex social emotional inappropriate remarks can develop unusual interests
what is semantic dementia related to
associated with focal left temporal atrophy
what are symptoms of progressive supranuclear palsy?
prominent executive deficits
gaze palsy (supranuclear)
early falls and parkinsonism esp affecting axial muscles
maybe midbrain atrophy on MRI
what are symptoms in corticobasal degeneration
prominent parietal deficits
asymmetric limb apraxia, rigidity
maybe aymmetric fronto-parietal atrophy
what are signs of PSP on MRI
mickey mouse
hummingbird
What are causes of vascular dementia
large artery disease cardiac embolic events small vessel disease thrombophilias haematologic factors haemodynamic mechanisms specific arteriopathies haemorrhages hereditary, cerebral amyloid angiopathies
what are lesion types on vascular dementia
arterial territorial infarct distal field/watershed infarct lacunar infarct ischaemic white matter change incomplete ischaemic injury
what does vascular dementia show on MRI with multi infarct
multiple strokes
stepwise course
plateaus
what does vascular dementia show on mri affected in strategic infarct
thalamus, basal ganglia
what does vascular dementia show in subcortical on MRI
dysexecutive syndrome memory deficit impaired recall relatively intact recognition subcortical slowing bradyphrenia depression mood changes episodes with UMN signs, brisk facial jerks urinary frequency and incontinence emotional incontinence extrapyramidal signs gait disorder
what are the MRI features from CADASIL, what is affected
involvement of areas not usually involved in atherosclerotic diseases
external capsule
anterior temporal lobe
what is common in vascular dementia
atherosclerosis
vasculitis
what young onset dementias are with peripheral neuropathy
CTX HIV mitochondrial Lyme neuroacanthocytosis
what young onset dementias are with dystonia
Wilson's Kuf's MLD Hallervorden-Spatz neuronal inclusion disorder HIV mitochondrial nvCJD lymphoma HD DRPLA neuroacanthosytosis neuroferritinopathy
what young onset dementias are present with ataxia
Wilson's Kuf's Lafora body NPC SCAs MLD nvCJD HIV HD DRPLA British
what are symptoms of cerebrotendinous xanthomatosis
tendon xanthomas
cataracts
dentate nucleus has a high signal on MRI
what are MRI features of limbic encephalitis shown on coronal FLAIR
coronal FLAIR shows medial temporal signal change reduced after treatment with development of medial temporal lobe atrophy
what is limbic encephalitis caused by and what are symtoms?
cause - autoimmunity: LGI1, GABA.b.R, AMPAR, CASPR2
symptoms - subacute memory impairment, confusion, behavioural change, seizures
what is paraneoplastic limbic encephalitis caused by
cancer or tumour in small cell lung(anti-Hu, CRMP5/CV2, ANNA-3) testis (anti-Ma2) lymphoma (CRMP5/CV2), ovary (anti-NMDAR) breast (anti-amphiphysin)
what infections are linked to limbic encephalitis
herpesviruses e.g. HSV2 HHV6/7
what connective tissue diseases are linked to limbic encephalitis
behcets
sjogren
sarcoid
relapsing polychondritis
what is a mimic syndrome of limbic encephalitis
temporal lobe tumour
