Stroke Flashcards
Cerebellar stroke - pathophysiology
Circulation to the cerebellum is impaired due to a lesion of:
- the superior cerebellar artery,
- anterior inferior cerebellar artery or
- the posterior inferior cerebellar artery (also known as lateral medullary syndrome)
Features of cerebellar stroke?
It may present similarly to vestibular neuritis
- vertical nystagmus
- patients can’t stand without support - even with eyes open
What is vertical nystagmus suggestive of?
A CENTRAL cause of vertigo
Criteria of Total anterior circulation infarct
- unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
- homonymous hemianopia
- higher cognitive dysfunction e.g. dysphasia
involves middle and anterior cerebral arteries
all 3 of the above criteria are present
Criteria of Partial anterior circulation infarcts
involves smaller arteries of anterior circulation e.g. upper or lower division of middle cerebral artery
2 of the criteria are present
- unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
- homonymous hemianopia
- higher cognitive dysfunction e.g. dysphasia
Criteria of lacunar infarcts
involves perforating arteries around the internal capsule, thalamus and basal ganglia
presents with 1 of the following:
- unilateral weakness (and/or sensory deficit) of face and arm, arm and leg or all three.
- pure sensory stroke.
- ataxic hemiparesis
Most commonly presents as a pure MOTOR HEMIPARESIS, pure SENSORY stroke
SENSOTIMOTOR stroke
ATAXIC hemiparesis or dysarthria/clumsy hand syndrome
Criteria of posterior circulation infarcts
involves vertebrobasilar arteries presents with 1 of the following: 1. cerebellar or brainstem syndromes 2. loss of consciousness 3. isolated homonymous hemianopia
Lateral medullary syndrome?
(posterior inferior cerebellar artery)
aka Wallenberg’s syndrome
ipsilateral: ataxia, nystagmus, dysphagia, facial numbness, cranial nerve palsy e.g. Horner’s
contralateral: limb sensory loss
Weber’s syndrome
type of stroke midbrain stroke syndrome ipsilateral III palsy - diplopia; ptosis; afferent pupillary defect contralateral weakness (contralateral hemiplegia)
Indications a stroke is ischaemic rather than haemorrhagic?
Carotid bruit
previous TIA
atrial fibrillation
ischaemic heart disease
What is the ROSIER score
A variant of the FAST screening tool which is useful for medical professionals
What is incorporated in the ROSIER score
Loss of consciousness or syncope = - 1 point
Seizure activity = - 1 point
New, acute onset of: • asymmetric facial weakness = + 1 point • asymmetric arm weakness= + 1 point • asymmetric leg weakness = + 1 point • speech disturbance = + 1 point • visual field defect = + 1 point A stroke is likely if >0.
What is the first investigation fro a suspected stroke ?
A NON contrast CT head scan
DVLA - stroke or TIA
1 month off driving, may not need to inform DVLA if no residual neurological deficit
DVLA - multiple TIAs
3 months off driving and inform DVLA
Management of a TIA
Immediate antithrombotic therapy:
give ASPIRIN 300 mg immediately, unless:
1. the patient has a bleeding disorder or is taking an anticoagulant (needs immediate admission for imaging to exclude a haemorrhage)
2. the patient is already taking low-dose aspirin regularly: continue the current dose of aspirin until reviewed by a specialist
3. Aspirin is contraindicated: discuss management urgently with the specialist team
If patient has had more than 1 TIA, or a cardioembolic source or severe carotid stenosis…
(Crescendo TIA)
Discuss the need for admission or observation urgently with a stroke specialist
If the patient has had a suspected TIA in the last 7 days…
Arrange urgent assessment (within 24 hours) by a specialist stroke physician
Advise the person not to drive until they have been seen by a specialist.
If the patient has had a suspected TIA which occurred more than a week previously…
Refer for specialist assessment as soon as possible within 7 days
Advise the person not to drive until they have been seen by a specialist.
Further management for a stroke…
After initial management
Antithrombotic therapy:
- clopidogrel is recommended first-line (as for patients who’ve had a stroke)
- aspirin + dipyridamole should be given to patients who cannot tolerate clopidogrel
Definition of TIA
The definition of a TIA is now TISSUE-based, not time-based: a transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischaemia, WITHOUT acute infarction
It is no longer a focal ischaemic event with symptoms lasting <24 hours.
(Even if symptoms have resolved, evidence of infarct on imaging leads to a diagnosis of stroke rather than a TIA.)
Management of acute ischaemic stroke
Aspirin 300mg immediately
Continued for 2 weeks after which time long - term antithrombotic treatment should be initiated.
- Clopidogrel
- Aspirin + dipyridamole if clopidogrel
Lacunar stroke pathophysiology
Occlusion of one of the penetrating arteries that provides blood to the brain’s deep structures.
Thrombectomy in acute ischaemic stroke
An extended target time of 6-24 hours may be considered if there is the POTENTIAL TO SALVAGE BRAIN TISSUE, as shown by imaging such as CT perfusion or diffusion-weighted MRI sequences showing LIMITED INFARCT core volume
NICE recommends to offer thrombectomy and thrombolysis to people who have had an ischaemic stroke with CT evidence within 6 hours of symptom onset