Neurology Flashcards
What is essential tremor?
autosomal dominant tremor
affects both upper limbs
features of essential tremor
postural tremor : worse if arms outstretched. nothing on relaxed
improved by alcohol and rest
mc cause of titubation (head tremor)
management of essential tremor
1st line: propranolol
primidone sometimes
most common causes of dementia
1st: alzheimers
2nd: vascular and lewy body
assesment tools of dementia
delayed/difficult diagnosis
recommended assesment tool: 10-cs or 6CIT
non recommended but can do: AMTS, GPCOG, MMSE (24 or less/30 is dementia)
initial investigations in dementia
primary care: blood screen to exclude reversible causes eg hypothyroidism
fbc, u+e, lft, calcium, glucose , esr/crp, tft, vit b12, folate.
secondary care: neuroimaging - exclude subdural haematoma, normal pressure hydrocephalus.
Define Delirium
acute confusional state.
affects 30% of elderly admitted to hospital.
presdisposing factors to delirium
age>65
dementia background
significant injury eg hip fracture
polypharmacy
frailty/multimorbidity
precipitating factors for delirium
infection: uti
environmental change
severe pain
alcohol withdrawal
constipation
any significant cv, resp, neuro, endo condition
metabolic: hypercalcaemia, hypoglycaemia, hyperglycaemia, dehydration
features of delirium
memory disturbance (loss of short term>long term)
mood change
visual hallucination
disturbed sleep cycle
possibly agitated/withdrawn
poor attention
disoriented
how would you manage delirium?
tx underlying cause
change environment
haloperidol 0.5mg : 1st line sedative
possibly olanzapine
if parkinson patient, antipycotic worsen parkinsonism symptom - careful reduction of parkinson medication helpful.
if sx require urgent tx give atypical antipsychotic like quetiapine/clozapine
difference between delirium and dementia (favouring delirium)
acute onset
impaired conciousness
fluctuating symptoms - worse @ night, periods of normality
abnormal perception (illusions and hallucinations)
agitation, fear
delusions
depression vs dementia (favouring depression)
short history, rapid onset
patient worried about poor memory
reluctant taking tests, disappointed w/ results
MMSE: variable
global memory loss - dementia is recent memory loss
biological sx: wt loss, sleep disturbance
what is alzheimers?
progressive degenerative disease of the brain.
rf of alzheimers
increasing age
fhx of alzheimers
caucasian
downs syndrome
apoprotein E allele E4 - encodes a cholestrol transport protein
5% cases - inherited autosomal dominant trait. mutation in amyloid precursor protein (chr 21) , presenilin 1 (chr 14) and presenilin 2 (chr 1) genes - thought to cause inherited form
Pathological changes for alzheimers
macroscopic: widespread cerebral atrophy, particular involves cortex and hippocampus
microscopic: cortical plaques due to deposition of type A - beta - amyloid protein and intraneuronal neurofibrillary tangles caused by abnormal aggregation of tau protein
hyperphosphorylation of tau protein linked to AD
biochemical: deficit of acetylcholine from damage to an ascending forebrain projection
what are neurofibrillary tangles?
paired helical filaments made from tau protein.
in AD tau proteins excessively phosphorylated= impaired function
what is tau protein?
Alzhiemers
protein interacting with tubulin.
stabilises microtubules
promotes tubulin assembly into microtubules
how would you manage alzheimers? (non-pharmacological)
activities to promote wellbeing tailored to preference
group cognitive stimulation therapy - mild/moderate dementia
group reminiscence therapy , cognitive rehab
how would you manage alzheimers (pharmacological mx)
acetylcholinesterase inhibitors (donepezil, galantamine, rivastigmine) - mild/moderate
memantine - nmda receptor antagonist. - 2nd line or monotherapy in severe alzheimers
moderate to severe: acetylcholineesterase inhibitor + memantine
moderate alzheimers intolerant of/contraindication of acetylcholinesterase inhibitors: memantine
how would you manage non cognitive symptoms in alzheimers?
NO to antidepressants for mild/moderate depression in patients with dementia
antipsycotics only for patient at risk of harming themselves or others/agitation/hallucination/delusions causing severe distress (increased risk of mortality)
which drug is contraindicated in alzheimers treatement in patients with bradycardia?
donepezil (Acetylcholine esterase inhibitor)
adverse effect: insomnia
causes of dementia
common : alzheimers,
lewy body (10-20%), cerebrovascular disease : multi-infarct dementia (10-20%)
rarer (5%) - huntingtons, CJD, picks disease (atrophy of frontal/temporal lobes), HIV (50% of AIDS pts)
important differentials for dementia
hypothyroid, addisons
b12/folate/thiamine def
syphilis
brain tumour
normal pressure hydrocephalus
subdural haematoma
depression
chronic drug use: alcohol, barbiturates
what is lewy body dementia?
20% of dementia cases.
lewy bodies (alpha-synuclein cytoplasmic inclusions) in substantia nigra, paralimbic and neocortical areas.
where would you find lewy bodies
substantia nigra
paralimbic
neocortical areas
what percentage of alzherimers patients have lewy bodies?
40%
features of lewy body dementia
parkinsonism
visual hallucination - delusion and non-visual hallucination too)
progressive cognitive impairement - BEFORE PARKINSONISM. - parkinsons is motor symptoms a yr before cognitive.
FLUCTUATING COGNITION COMPARED WITH DEMENTIA
HOW DOES LEWY BODY DEMENTIA COMPARE WITH ALZHEIMERS
IN LEWY BODY EARLY IMPAIREMENT IN ATTENTION AND EXECUTIVE FUNCTION RATHER THAN JUST MEMORY LOSS.
diagnosis of lewy body dementia
clinical
single-photon emission computed tomography (SPECT) / DaTscan.
isotope used: 123-I-FP-CIT - radioisotope.
what is the sensitivity and specifity of SPECT in diagnosing lewy body dementia
sensitivity: 90%
specificity: 100%
how would you manage lewy body dementia?
acetylcholinesterase inhibitors - donepezil, rivastigmine)
AVOID NEUROLEPTICS - pts could get irreversible parkinsonism.
what drug should lewy body dementia patients avoid?
NEUROLEPTICS - can develop irreversible parkinsonism.
causes of parkinsonisms
parkinson’s
drug-induced eg antipsychotics, metoclopramide
progressive supranuclear palsy - neurological condition causes issue with balance, movement,vision,speech, swallowing.
wilsons disease
post-encephalitis
toxins: carbon monoxide, MPTP
what is the first line anti-emetic ( used for parkinsons?
domperidone - doesnt cross blood brain barrier.
no extra-pyramidal side effects (movement disorder, parkinonism, tremor)
what is vascular dementia?
group of syndromes of cognitive impairement caused by different mechanisms causing ischaemia or haemorrhage secondary to cerebrovascular disease.
epidemiology of vascular dementia
17% of uk dementia.
prevalence following first stroke depends on location/size of infarct, interval after stroke, age. overall stroke doubles risk.
incidence increase with age
subtypes of vascular dementia
stroke related - multi-infarct or single-infarct dementia
subcortical - caused by small vessel disease
mixed - presence of both VD and Alzheimers
risk factors of Vascular dementia
hx of tia
AF
HTN
DM
SMOKING
OBESITY
CORONARY HEART DISEASE
HYPERLIPIDEMIA
FHX OF STROKE/CV
can vascular dementia be inherited?
rarely
if so CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
presentation of vascular dementia typically
several months/years of hx of a sudden or stepwise deterioration of cognitive function.
symptoms of vascular dementia
speed of progression and sx may vary :
seizures
gait disturbance
emotional disturbance
memory disturbance
attention and concentration difficulty
focal neurological abnormality: visual disturbance, sensory/motor sx.