Stroke And TIA Flashcards
What is a cerebrovascular accident (aka stroke)
sudden onset neurological symptoms caused by interruption in the vascular supply of the brain
State the 2 types of stroke and how common each are
- Ischaemic - 80%
- Haemorrhagic - 20%
What is an ischaemic stroke
decrease in blood flow due to arterial occlusion/stenosis
Give 3 causes of an ischaemic stroke
- thrombosis
- embolus
- Plaque
Give 5 RFs of an ischaemic stroke
- HTN
- Smoking
- T2DM
- Atrial fibrillation
- TIA
What are total anterior circulation infarcts and how do they present
- involves middle and anterior cerebral arteries
Presents with all 3 of the following:
1. contralateral hemiparesis and/or hemisensory loss of the face, arm & leg
2. homonymous hemianopia
3. higher cognitive dysfunction e.g. dysphasia, apraxia, agnosia
What are partial anterior circulation infarcts and how do they present
- involves smaller arteries of anterior circulation
- Presents with 2 of the following
1. unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
2. homonymous hemianopia
3. higher cognitive dysfunction e.g. dysphasia, visuospatial disorder
How would a stroke in the anterior cerebral artery present
- Contralateral hemiparesis and sensory loss
- Lower limbs more affected than upper limbs
How would a stroke affecting the middle cerebral artery present
- Aphasia/ dysphasia
- Contralateral hemiparesis and sensory loss
- Upper limbs> lower limbs
- Contralateral homonymous hemianopia
What are lacunar infarcts and how would they present
- involves perforating arteries around the internal capsule, thalamus and basal ganglia
- presents with 1 of the following:
1. clumsy hand and dysarthria
2. pure hemisensory stroke
3. pure motor hemiparesis
4. sensori-motor stroke
5. ataxic hemiparesis
What are posterior circulation infarcts and how do they present
- involves vertebrobasilar arteries
- presents with 1 of the following:
1. cerebellar dysfunction - DANISH
2. loss of conscioussness/ sleepiness (reduced GCS)
3. isolated homonymous hemianopia
4. Brainstem: bilateral sensory/motor deficit
5. ipsilateral CN palsy and contralateral limb weakness
How would a stroke affecting the posterior cerebral artery present
- Vision loss - contralateral homonymous hemianopia
- macular sparing
- visual agnosia - impairment in recognition of visually presented items
How would a vertebrobasilar artery stroke present
- Cerebellar signs (Vanished)
- reduced consciousness
- balance disorders
How are ischaemic strokes diagnosed
- Non contrast CT head
- glucose and electrolytes
- CT angiography - for candidates for thrombectomy
What would you expect to see on a non contrast CT of someone who has had an ischaemic stroke
- immediate: brightness in artery indicates clot within lumen
- Late: darkness of brain parenchyma, loss of grey matter-white matter differentiation
Why are serum electrolytes and glucose investigated for ischaemic strokes
To exclude stroke mimics such as hypoglycaemia and hyponatraemia
How is an ischaemic stroke treated
- <4.5h since Sx onset + haemorrhage excluded = thrombolysis (IV alteplase) + thrombectomy
- 300mg oral/ rectal aspirin should be given ASAP if haemorrhagic stroke has been excluded
- Maintain glucose, oxygen and hydration
- HTN should not be treated in the initial period following a stroke (unless prior to thrombolysis)
What is the standard target treatment time for thrombolysis in acute ischaemic stroke
- within 4.5 hours of symptom onset
- within 9 hours of onset (or midpoint of sleep in ‘wake up’ stroke) if there’s salvageable brain tissue on MRI/ CT perfusion imaging
What is the standard target treatment time for thrombectomy in acute ischaemic stroke
- within 6 hours of symptom onset
- within 24 hours post-stroke onset if imaging shows salvageable brain tissue
Give 4 absolute contraindications to thrombolysis
- Uncontrolled hypertension >200/120mmHg
- intracranial neoplasm
- stroke < 3 months
- aortic dissection
- recent head injury
- active bleeding
Give 3 relative contraindications to thrombolysis
- pregnancy
- Concurrent anticoagulation
- Major surgery / trauma in the preceding 2 weeks
What pharmacological interventions are used as prevention for ischaemic strokes
- Clopidogrel monotherapy
- if clopidogrel not tolerated/ contraindicated then give aspirin + dipyridamole lifelong
- Atorvastatin after 48h
Hypoglycaemia and hyponatraemia are examples of ‘stroke mimics’, give 2 more examples
- Hepatic encephalopathy
- Brain tumours
- seizures
- vestibular neuritis
- spinal cord lesion
What is a transient ischaemic attack (TIA)
a sudden transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischaemia, without acute infarction.
What is the most common cause of a TIA
Thrombo-emboli in the internal carotid artery
Give 5 ways a TIA may present
- visual loss: Amaurosis fugax, diplopia, homonymous hemianopia
- aphasia or dysarthria
- ataxia, vertigo, or loss of balance
- unilateral weakness or sensory loss
- typically resolves within 1 hour
What is amaurosis fugax
sudden and temporary loss of vision in one eye due to reduced blood flow to the retina
What investigations should be ordered for a suspected TIA
- MRI brain with diffusion weighted imaging
- Blood glucose - exclude hypoglycaemia
- FBC, PTT, INR
- Serum electrolytes
- ECG
- All TIA patients should have an urgent carotid doppler unless they are not a candidate for carotid endarterectomy
If a TIA is suspected, when should an urgent CT head be requested and why
should only be done if the patient is taking anticoagulation or has a bleeding disorder, admit urgently to exclude haemorrhage
How is a confirmed TIA managed
- Dual antiplatelet therapy:
clopidogrel (initial dose 300 mg followed by 75 mg od) + aspirin (initial 300 mg followed by 75 mg od for 21 days) followed by monotherapy with clopidogrel 75 mg od - if DAPT not suitable: clopidogrel monotherapy
- start atorvastatin (oral OD)
What is an extradural haemorrhage (EDH)
Haemorrhage between the dura mater and the inner surface of the skull
What causes EDH
Typically bleeding from the middle meningeal arteries typically caused by low-impact trauma
Why is the middle meningeal artery susceptible to bleeding following a skull fracture
- The pterion is where the parietal, frontal, sphenoid and temporal bones fuse
- Bone at this location is relatively thin so vulnerable to fracture
- MMA lies underneath pterion therefore fracture can result in rupture of the MMA
What age group is at a higher risk of an EDH
Young adults 20-30
Why does the risk of an EDH reduce as we age
Dura is more firmly adhered to skull as you age
Describe the typical symptoms of an EDH
- Headache
- N+V
- Confusion
- fixed and dilated pupil
- initially loses, briefly regains and then loses again consciousness after low-imapct head injury (lucid interval)
- Progressively decreasing level of consciousness
Describe the pathophys of an EDH
- bleeding into extradural space causes raised ICP
- results in brain compression and midline shift
What imaging should be done for a EDH
- GS = CT head
- Xray - fracture
What are features of an EDH that may be seen on a CT
- Bi-convex (lemon) hyperdense collection
- midline shift
- limited by suture lines of skull
- brainstem herniation
Treatment of an EDH
- ABCDE
- IV mannitol to reduce ICP
- Craniotomy and evacuation of haematoma
What is a subdural haemorrhage (SDH)
Collection of blood between the dura mater and arachnoid mater
What is the most common cause of a SDH
trauma rupturing the bridging veins
Give 4 RFs of a SDH
- Recent trauma - fall, blow to the head
- Over 65
- Coagulopathy or anticoagulant use
- Brain atrophy - dementia, alcohol abuse
What is an acute subdural haemorrhage
where symptoms develop within 48 hours of a high-impact injury, characterised by rapid neurological deficit
What is classed as a subacute SDH
3-21 days post-injury, with a gradual progression
What is a chronic subdural haemorrhage
Common in the elderly, developing over weeks to months. Patients may not recall a specific head injury.
Presentation of a subdural haemorrhage
- Fluctuations in the level of consciousness and confusion
- Headache: Often localised to one side
- Focal Neurological Deficits: unilateral weakness, aphasia or visual field defects
- seizures
- signs of raised ICP - bradykinesia, hypertensions and respiratory irregularities (cushing’s triad)
Give 4 physical exam findings of a subdural haemorrhage
- Papilloedema - raised ICP
- Pupil Changes: Unilateral dilated pupil - compression of 3rd cranial nerve
- Gait Abnormalities: ataxia or weakness in one leg
- Hemiparesis
What imaging should be done for a SDH and describe a positive finding
- Non contrast CT head
- Crescent shaped (Concave) collection of blood
- not limited by suture lines
- midline shift
How would a CT differ in acute, subacute and chronic SDHs
- Acute - hyperdense (bright white)
- subacute - hyperdense or isodense
- Chronic - hypodense (black/grey)
How is a subdural haemorrhage managed
- surgical decompression with craniotomy
- conservatively : observe, monitor and follow-up
- Correction of coagulopathy
- phenytoin or levetiracetam if Hx of seizures
When is surgery considered for a subdural haemorrhage
- > 10mm size
- expansile
- significant neurological dysfunction
What is a subarachnoid haemorrhage
Spontaneous bleeding between the arachnoid and pia mater
What is the most common cause of a subarachnoid haemorrhage
Rupture of a cerebral aneurysm - mainly communicating branches of the circle of willis
Give 5 RFs for a subarachnoid haemorrhage
- HTN
- Smoking
- FHx
- Coarctation of aorta
- Genetic conditions
Give 2 genetic conditions that increase the risk of having a spontaneous subarachnoid haemorrhage
- Polycystic kidney disease
- CT disorders - Marfans, ehlers danlos
Give 4 symptoms of a subarachnoid haemorrhage
- Severe and sudden thunderclap occipital headache, peaking in intensity within 1-5 mins
- N+V
- seizures/ coma
- meningism (photophobia, neck stiffness)
Give 4 signs of a subarachnoid haemorrhage
- 3rd nerve palsy
Meningism: - neck stiffness
- kernig’s and brudzinski +ve
What is the first line investigation for a suspected subarachnoid haemorrhage
non-contrast CT head - hyperdense blood in a star pattern
When suspecting a subarachnoid haemorrhage, if CT head is done within 6 hours of symptom onset and is normal what should be done next
- do not do a lumbar puncture
- consider alternative diagnosis
When suspecting a subarachnoid haemorrhage, if CT head is done more than 6 hours after symptom onset and is normal what should be done next
- do a lumbar puncture to confirm/ exclude diagnosis
- lumbar puncture should be done at least 12 hours after the start of the headache
What CSF findings are consistent with a subarachnoid haemorrhage
- xanthochromia
- normal or raised opening pressure
When investigating a subarachnoid haemorrhage, why is the lumbar puncture done at least 12h after the onset of the headache
to allow the development of xanthochromia (the result of red blood cell breakdown)
After spontaneous subarachnoid haemorrhage is confirmed, what investigation should be done to identify the causative pathology
CT intracranial angiogram - identify vascular lesion
How is a subarachnoid haemorrhage managed
- immediate referral to neurosurgery as soon as CT confirms SAH
- Supportive - bed rest, analgesia, VTE prophylaxis, discontinue antithrombotics
- oral Nimodipine (CCB)
- Surgery within 24h:
- endovascular coiling by interventional neuroradiologists (mc) or
- craniotomy and clipping by a neurosurgeon
Why is Nimodipine prescribed for a subarachnoid haemorrhage
Prevent vasospasms which result in brain ischaemia
Give 4 complications of a subarachnoid haemorrhage
- Re-bleeding (high mortality)
- Vasospasm (typically 1-2w after onset)
- Hydrocephalus (increased CSF)
- hyponatraemia due to SIADH
What is an intracerebral haemorrhage
Sudden bleeding into brain tissue due to rupture of blood vessels
Describe the presentation of an intracerebral haemorrhage
Presents the same as an ischaemic stroke - numbness/ weakness, speech disturbances
* more likely to lose consciousness
* more likely to have a headache
How is an intracerebral haemorrhage investigated
NCCT head:
- midline shift if large
- acute bleed within brain
How is an intracerebral haemorrhage treated
- BP control - 140mmHg aim
- Reduce ICP - IV mannitol
- Stop anticoagulants immediately
- Neurosurgical referral
What tool is used to assess stroke symptoms in an acute setting
ROSIER (‘Recognition Of Stroke In the Emergency Room’)
