Stroke Week Flashcards
what percentage of TIAs will show damage on MRI
50%
how long does a true TIA last
less than an hour
which subtype of stroke is most common
ischaemic
what happens in ischaemic stroke
blood clot stops the flow of blood to an area of the brain
what happens in haemorrhagic stroke
weakened/diseased blood vessels rupture
stroke risk increases in women:
- pregnancy
- have preeclampsia
- birth control
- use HRT
- have migraines with aura and smoke
- have AF
stroke - FAST
- Facial weakness
- Arm weakness
- Speech problems
- Time to call 999
what is dysphasia
impairment of language processing
anterior cerebral artery/middle cerebral artery features
- hemiparesis
- hemisensory loss
- hemianopia (affects optic tract)
- dysphasia (left MCA)
- sensory/visual inattention/neglect (right MCA)
Lacunar syndromes (perforating arteries) features
- pure motor stroke
- pure sensory stroke
- sensorimotor stroke (less likely than a pure one)
- clumsy hand dysarthria (slight weakness and clumsiness of the hand with slurred speech)
- ataxic hemiparesis (ataxia and usually mild hemiparesis affecting the same side)
what does ataxia mean
without coordination
what does the posterior circulation supply?
- brainstem, cerebellum
- occipital lobes
- medial temporal lobes
- posterior part of the deep hemisphere, mainly the thalamus
posterior circulation stroke features
hemianopia (occipital cortex)
brainstem and cerebellar:
- hemiparesis/hemisensory loss
- ataxia
- dysarthria
- due to cranial nerve nuclei involvement - vertigo, diplopia, facial nerve palsy, tongue palsy, dysphagia
bilateral symptoms - basilar artery syndrome
how are strokes classified in Oxford Stroke Classification?
TACS, PACS, LACS, POCS
What does TACS stand for?
Total Anterior Circulation Syndrome
in the oxford stroke classification, what is the most severe type of stroke?
TACS
what is the number one cause of stroke
high BP
what does PACS stand for
Partial Anterior Circulation Syndrome
what percentage of PACS patients are alive and independent at 1 year?
55%
what happens in Lacunar Syndrome (LACS)?
small infarcts in the deeper parts of the brain and in the brainstem
what causes Lacunar syndrome
occlusion of a single deep penetrating artery
lacunar syndrome prognosis
best of all the strokes, 60% of patients alive and independent at 1 year
what does POCS stand for
Posterior Circulation Syndrome
give examples of stroke mimics
- subdural/ extradural haematoma
- seizure/ postictal signs
- migraine
- space occupying lesion
- metabolic disturbance (glucose!)
- peripheral vestibular issue
- functional neurological disorder
does a history of cognitive impairment point you more towards a stroke diagnosis or away from it?
away
main causes of ischaemic stroke
- large artery disease
- cardioembolic
- lacunar
main causes of haemorrhagic stroke
- hypertensive
- cerebral amyloid angiopathy
what is the ischaemic core?
area of brain which has developed necrosis.
cerebral blood flow <20%
penumbra meaning
area of brain with reduced cerebral flow, but also getting supply of O2 and glucose from collateral arteries.
what is the ischaemic cascade
a series of biochemical reactions that are initiated in the brain and other aerobic tissues after seconds to minutes of ischaemia
ischaemic cascade detail
switch from aerobic to anaerobic metabolism
accumulation of lactic acid
Na/K channel dysregulation - cytotoxic oedema
Na/K channel dysregulation - increase Ca within neuron:
1) excitotoxicity
2) degradative enzymes
3) formation of radicals
Mitochondrial apoptotic factors
when does vasogenic oedema start
4-6 hours after ischaemia
post stroke inflammation
- ischaemia
- damage-associated molecular patterns
- inflammation: macrophages/immune response
- anti-inflammatory
- liquifactive necrosis
TOAST 5 types of ischaemic stroke
- large artery atherosclerosis
- cardioembolism
- small vessel disease
- stroke of other determined aetiology
- stroke of undetermined aetiology
which TOAST is most common (type of ischaemic stroke)
large artery atherosclerosis
what is small artery disease stroke caused by
lipohyalinosis (thickened vessel wall with luminal narrowing)
NIHSS score and severity
1-4 mild
5-15 moderate
16-20 moderate to severe
21-42 severe
what is the time frame for getting thrombolysis in stroke
within 4.5hrs after onset of symptoms
what is thrombolysis in stroke
lysis (break up) of clot by tissue plasminogen activator (usually TNK (tenecteplase))
what is the goal of thrombolysis
aim to restore flow and save penumbra
name some contraindications of thrombolysis
- previous intracerebral haemorrhage or infarct
- dose of DOAC in the last 24-48hrs
- pregnancy
- recent head injury/stroke/surgery
- severe comorbidities
- seizure
- platelets below 100, severe anaemia
- severe hypertension (can be treated first)
is old age a contraindication for thrombolysis in stroke
no
complications of thrombolysis
- haemorrhage
- anaphylaxis (very rare)
- angioedema
what puts patients at higher risk of angioedema as a complication of thrombolysis
being on ACEi
if it’s appropriate (e.g. ischaemic stroke) and there are no contraindications, when should thrombectomy be offered in stroke
asap, and within 6hrs of symptom onset
primary intracerebral haemorrhage - lobar vs deep
lobar - may be more related to cerebral amyloid angiopathy
deep - may be more related to effects of blood pressure
hyperacute stroke management steps
- urgent imaging
- thrombolysis/thrombectomy
- BP lowering
- Stroke unit care
- swallow assessment, nutrition and hydration
- secondary prevention medication
ASPECTS score - what would a normal brain score?
10
(would lose a point for each area damaged)
what % of ischaemic strokes are large vessel occlusion?
10%
anterior cerebral artery stroke associated effects
Contralateral hemiparesis and sensory loss,
lower extremity > upper
middle cerebral artery stroke associated effects
Contralateral hemiparesis and sensory loss,
upper extremity > lower
Contralateral homonymous hemianopia
Aphasia
posterior cerebral artery stroke associated effects
Contralateral homonymous hemianopia with macular sparing
Visual agnosia
Weber’s syndrome (branches of the posterior cerebral artery that supply the midbrain) stroke associated effects
Ipsilateral CN III palsy
Contralateral weakness of upper and lower extremity
Posterior inferior cerebellar artery (lateral medullary syndrome, Wallenberg syndrome) stroke associated effects
Ipsilateral: facial pain and temperature loss
Contralateral: limb/torso pain and temperature loss
Ataxia, nystagmus
Anterior inferior cerebellar artery (lateral pontine syndrome) stroke associated effects
Symptoms are similar to Wallenberg’s(Ipsilateral: facial pain and temperature loss
Contralateral: limb/torso pain and temperature loss
Ataxia, nystagmus), but:
Ipsilateral: facial paralysis and deafness
Retinal/ophthalmic artery stroke associated effects
Amaurosis fugax
Basilar artery stroke associated effects
‘Locked-in’ syndrome
