Neurology: TIA & Stroke Flashcards
What is a TIA>
Is a transient (less than 24 hours, typically 30 minutes) period of neurological dysfunction without evidence of acute infarction.
A transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischaemia, without acute infarction.
Risk factors for TIA?
- Diabetes mellitus
- High cholesterol
- HTN
- Smoking
- FH of CVS disease/stroke
- AF (for cardioembolic TIAs)
Clinical features of TIA?
Similar to stroke BUT completely resolves within 24 hours of onset.
- unilateral weakness or sensory loss.
- aphasia or dysarthria
- ataxia, vertigo, or loss of balance
- visual problems e.g. sudden transient loss of vision in one eye (amaurosis fugax), diplopia, homonymous hemianopia
Management of TIA?
1) Aspirin 300mg
2) Consider concurrent PPI use (anyone with dyspepsia)
3) Specialist assessment
What are 3 exceptions to giving 300mg aspirin immediately in TIA?
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
If a patient has a a bleeding disorder or is taking an anticoagulant and present with TIA/stroke symptoms, what should you do?
needs immediate admission for imaging to exclude a haemorrhage
Referral for patients who have had a suspected TIA in the last 7 days?
arrange urgent assessment (within 24 hours) by a specialist stroke physician
Referral for patients who have had a suspected TIA which occurred more than 7 days ago?
refer for specialist assessment as soon as possible within 7 days
Driving and TIA?
Advise the person not to drive until they have been seen by a specialist.
What imaging is indicated in a TIA?
MRI –> is preferred to determine the territory of ischaemia, or to detect haemorrhage or alternative pathologies
It should be done on the same day as the specialist assessment if possible
Investigations in TIA?
1) Neuroimaging: MRI
2) Carotid imaging: urgent carotid doppler
Why is carotid imaging important in TIA?
atherosclerosis in the carotid artery may be a source of emboli in some patients
When is a carotid doppler not indicated in TIA?
If they are not a candidate for carotid endarterectomy
2ary prevention following TIA?
1) antiplatelet therapy to follow on from initial aspirin therapy: clopidogrel
2) lipid modification: atorvastatin 20–80 mg daily
What is 1st line antiplatelet in 2ary prevention of TIA?
Clopidogrel
What can be given during 2ary prevention of TIA in patients who cannot tolerate clopidogrel?
aspirin + dipyridamole
What is the aim of statin therapy in 2ary prevention of TIA?
To reduce non-HDL cholesterol by more than 40%
What is a carotid artery endarterectomy?
a surgical procedure to remove a build-up of fatty deposits (plaque), which cause narrowing of a carotid artery.
When is a carotid artery endarterectomy recommended?
Recommend if the patient has suffered stroke or TIA in the carotid territory and is not severely disabled.
Should ONLY be considered if carotid stenosis >70%.
What is a stroke?
A sudden interruption in the vascular supply of the brain
Characterised by rapidly developing signs of focal or global disturbance of cerebral functions which lasts longer than 24 hours OR leads to death.
What are the 2 main types of stroke?
1) Ischaemic stroke (85%)
2) Haemorrhagic stroke (13%)
Mechanism of an ischaemic stroke?
Reduction or complete blockage of blood flow to part of the brain, resulting in tissue hypoperfusion
What are some causes of an ischaemic stroke?
1) Embolism (from elsewhere)
2) Thrombosis e.g. due to atherosclerotic plaque rupture within cerebral vessel
3) Small vessel disease e.g. chronic HTN nges in the small vessels of the brain
4) Cardioembolic e.g. in F
5) Systemic hypoperfusion e.g. cardiac arrest
6) Cerebral venous sinus thrombosis
How can chronic HTN lead to an ischaemic stroke?
Chronic hypertension causes changes in the small vessels of the brain. Middle layer of the vessel (tunica media) becomes enlarged and causes narrowing/occlusion of the vessels.
How can cardiac arrest lead to ischaemic stroke?
Systemic hypoperfusion –> supply to entire brain is reduced 2ary to systemic hypotension e.g. cardiac arrest
Mechanism of a haemorrahge stroke?
Occur 2ary to rupture of a blood vessel (usually arterioles and small arteries) or abnormal vascular structure within the brain.
Causes of a haemorrhagic stroke?
1) HTN
2) Trauma
3) Bleeding disorders
4) Anticoagulation
5) Age
6) Vascular malformations
7) Illicit drug use
Most important risk factor of a haemorrhagic stroke?
HTN
What are the 2 types of haemorrhagic stroke?
1) Intracerebral haemorrhage
2) Subarachnoid haemorrhage
What are the 2 main subtypes of ischaemic strokes?
1) Thrombotic stroke
2) Embolic stroke (can be blood clot, fat, air, or clumps of bacteria)
What is an important cause of embolic stroke?
AF
Is smoking a risk factor for haemorrhagic or ischaemic stroke?
Ischaemic
What is an intracerebral haemorrhage?
Bleeding into brain tissue 2ary to ruptured blood vessel (intraparenchymal and/or intraventricular)
Causes of intracerebral haemorrhage?
1) Spontaneous
2) Result of bleeding into an ischaemic infarct
3) Tumour
4) Rupture of aneurysm
What is a subarachnoid haemorrhage (SAH)?
bleeding outside of brain tissue between pia mater and arachnoid mater
Causes of an SAH?
1) rupture of intracranial saccular aneurysm
2) anticoagulants
3) arterial dissections etc
What is a silent stroke?
radiological or pathological evidence of an infarction or haemorrhage not caused by trauma that doesn’t cause any noticeable symptoms
Features of a stroke?
A sudden onset of neurological symptoms suggests a vascular cause (e.g., stroke). Stroke symptoms are typically asymmetrical.
1) Limb weakness
2) Facial weakness
3) Dysphasia (speech disturbance)
4) Visual field defects (homonymous hemianopia)
5) Sensory loss
6) Ataxia and vertigo (posterior circulation infarction)
What symptoms may be seen in cerebral hemisphere infarcts?
1) contralateral hemiplegia: initially flaccid then spastic
2) contralateral sensory loss
3) homonymous hemianopia
4) dysphasia
What features may be seen in a brainstem infarction?
may result in more severe symptoms including quadriplegia and lock-in-syndrome
What are lacunar infarcts?
Lacunar infarcts are small (2 to 15 mm in diameter) noncortical infarcts caused by occlusion of a single penetrating branch of a large cerebral artery.
These are small infarcts around the basal ganglia, internal capsule, thalamus and pons.
What features may be seen in lacunar infarcts?
this may result in pure motor, pure sensory, mixed motor and sensory signs or ataxia
What is the leading cause of death and disability?
Stroke
Give some complications of a stroke
- Infection – hospital acquired and aspiration pneumonia
- Pressure sores
- Neurological problems e.g. seizures, delirium, cerebral oedema
- VTE
- Death
- Cardiac complications (due to shared aetiology)
- Depression & anxiety
- Mobility problems; hemiparesis, hemiplegia, ataxia, falls, spasticity & contractures, difficulty with activities of daily living
- Sensory problems; touch, temperature, pain
- Continence problems
- Fatigue
- Communication difficulties, difficulties with activities of daily living, mobility problems
- Sexual dysfunction
- Visual problems
The combined contraceptive pill carries a tiny increased risk of stroke.
Who is this risk higher in?
1) patients with migraines with aura
2) smokers over 34 years
3) those with a history of stroke or TIA.
Imaging investigation of choice in stroke?
Diffusion-weighted MRI scan
What classification is used in stroke?
Oxford Stroke Classification (also known as the Bamford Classification).
This classifies strokes based on the initial symptoms.
What criteria is assessed in the Oxford Stroke Classification?
1) unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
2) homonymous hemianopia
3) higher cognitive dysfunction e.g. dysphasia
What arteries are involved in a total anterior circulation infarct?
Middle and anterior cerebral arteries
What criteria from the Oxford Stroke Classification are present in a total anterior circulation infarct?
All 3 criteria
What arteries are involved in a partial anterior circulation infarct?
involves the anterior OR middle cerebral artery on the affected side.
What criteria from the Oxford Stroke Classification are present in a partial anterior circulation infarct?
2 of the criteria
OR
Higher cerebral dysfunction alone
What arteries are involved in a lacunar infarct?
involves perforating arteries around the internal capsule, thalamus and basal ganglia
How does a lacunar infarct present?
Presents with 1 of the following:
1) unilateral weakness (and/or sensory deficit) of face and arm, arm and leg or all three.
2) pure sensory stroke.
3) ataxic hemiparesis
What arteries are involved in a posterior circulation infarct?
involves vertebrobasilar arteries
Presentation of a posterior circulation infarct?
presents with 1 of the following:
- cerebellar or brainstem syndromes
- loss of consciousness
- isolated homonymous hemianopia
Is a decrease in the level of consciousness more common in haemorrhagic or ischaemic strokes?
Haemorrhagic
Is a headache more common in haemorrhagic or ischaemic strokes?
Haemorrhagic
Is N&V more common in haemorrhagic or ischaemic strokes?
Haemorrhagic
Are seizures more common in haemorrhagic or ischaemic strokes?
Haemorrhagic
What is the FAST mneumonic in stroke?
Face - ‘Has their face fallen on one side? Can they smile?’
Arms - ‘Can they raise both arms and keep them there?’
Speech - ‘Is their speech slurred?’
Time - ‘Time to call 999 if you see any single one of these signs.’
Is obesity a risk factor for haemorrhagic or ischaemic stroke?
Ischaemic
Initial maangement of stroke?
1) Neuroimaging (MRI or CT)
2) Aspirin 300mg for two weeks
3) Exclude hypoglycaemia
4) Admission to a specialist stroke centre
When is aspirin 300mg given in stroke?
started AFTER haemorrhage is excluded with a CT
Purpose of emergency neuroimaging in suspected stroke?
To see whether a patient may be suitable for thrombolytic therapy to treat early ischaemic strokes (i.e. to exclude haemorrhage)
If a stroke is deemed to be ischaemic, what is next step?
1) Give aspirin 300mg as soon as haemorrhagic stroke has been excluded.
2) Thrombolysis with alteplase (if criteria met)
What is criteria for thrombolysis in ischaemic stroke?
1) patients present with 4.5 hours of onset of stroke symptoms
2) the patient has not had a previous intracranial haemorrhage, uncontrolled hypertension, pregnant etc
Management of haemorrhagic stroke?
Majority not suitable for surgical intervention.
Management often supportive.
Stop anticoagulants (e.g. warfarin) and antithrombotics (e.g. clopidogrel).
Differentials for a stroke?
- Hypoglycaemia
- Drugs & alcohol toxicity
- Todd’s paresis (post seizures) – weakness of one side
- Subdural haematoma
- Seizure, migraine with aura, demyelination (multiple sclerosis), peripheral neuropathies (e.g. Bell’s palsy)
- Trauma
- Systemic or local infection; sepsis, encephalitis, CNS abscess
- Tumour
- Dementia
Symptoms of posterior stroke?
o Vertigo or dizziness
o Nystagmus
o N & V
o Head motion intolerance
o New gait unsteadiness
Bedside investigations in stroke?
o Blood glucose – rule out hypoglycaemia (can mimic stroke)
o 12-lead ECG – exclude arrythmias (e.g. AF)
o Hydration status
o Swallow assessment
If patients with stroke are unable to swallow 300mg aspirin orally, what is next option?
600mg PR if unable to swallow
Once a patient who has had an ischaemic stroke has been moved to stroke unit, further investigations & management plans can be carried out for risk factors.
What investigations can be considered?
1) Carotid stenosis
Investigation: Carotid dopplers for carotid stenosis (caused by atherosclerosis).
Management: Carotid endarterectomy
2) AF
Investigation: ECG
Management: Consider anticoagulation around 14 days post stroke
How long should patients be on 300mg aspirin following ischaemic stroke?
2 weeks
Features of a total anterior circulation infarct (TACI)?
1) Contralateral hemiparesis or hemiplegia
AND
2) Contralateral homonymous hemianopia
AND
3) Higher cerebral dysfunction (e.g. aphasia, neglect)
Are lower or upper extremeties affected more in an anterior cerebral infarct?
Lower
Associated effects of middle cerberal artery infarct?
Contralateral hemiparesis and sensory loss, upper extremity > lower
Contralateral homonymous hemianopia
Aphasia
Associated effects of posterior cerberal artery infarct?
Contralateral homonymous hemianopia with macular sparing
Visual agnosia
Associated effects of a basilar artery infarct?
Locked in syndrome
What do lacunar strokes have a strong association with?
HTN
Give some absolute contraindications to thrombolysis?
- Previous intracranial haemorrhage
- Seizure at onset of stroke
- Intracranial neoplasm
- Suspected subarachnoid haemorrhage
- Stroke or traumatic brain injury in preceding 3 months
- Lumbar puncture in preceding 7 days
- Gastrointestinal haemorrhage in preceding 3 weeks
- Active bleeding
- Pregnancy
- Oesophageal varices
- Uncontrolled hypertension >200/120mmHg
What is thrombectomy?
Thrombectomy involves using a specially-designed clot removal device inserted through a catheter to pull or suck out the clot, to restore blood flow.
Who is thrombectomy considered in?
Considered in patients with a confirmed blockage of the proximal anterior circulation or proximal posterior circulation.
When is thrombectomy considered?
It may be considered within 24 hours of the symptom onset
What is thrombectomy done alongside?
IV thrombolysis
What is thromboylsis done with in stroke?
Alteplase
What is alteplase?
a tissue plasminogen activator that rapidly breaks down clots.
Monitoring of patients post thrombolysis?
Patients need close monitoring for complications, particularly intracranial or systemic haemorrhage, with access to immediate imaging if bleeding is suspected.
Blood pressure is aggressively treated in what type of stroke?
Haemorrhagic
Surgical interventions are considered where there is significant carotid artery stenosis in stroke.
What are the 2 options?
1) Carotid endarterectomy (recommended in the NICE guidelines)
2) Angioplasty and stenting
2ary prevention of stroke?
1) Clopidogrel 75mg once daily (alternatively aspirin plus dipyridamole)
2) Atorvastatin 20-80mg (not started immediately – usually delayed at least 48 hours)
3) Blood pressure and diabetes control
4) Addressing modifiable risk factors (e.g., smoking, obesity and exercise)
Site of lesion: anterior cerebral artery
What are the associated effects?
Contralateral hemiparesis & sensory loss.
Lower extremity > upper.
Site of lesion: middle cerebral artery
What are the associated effects?
1) Contralateral hemiparesis and sensory loss: Upper extremity > lower.
2) Contralateral homonymous hemianopia
3) Aphasia
Site of lesion: posterior cerebral artery
What are the associated effects?
1) Contralateral homonymous hemianopia with macular sparing
2) Visual agnosia: impairment in recognising visually presented objects
What is Weber’s syndrome? What arteries are affected?
A form of midbrain stroke, infarct in branches of the posterior cerebral artery that supply the midbrain.
Associated effects of Weber’s syndrome?
1) Ipsilateral CN III palsy: eye being ‘down and out’ (i.e. depressed and abducted)
2) Contralateral weakness of upper and lower extremity
Site of lesion: posterior infererior cerebellar artery
What are the associated effects?
This is also known as lateral medullary syndrome and Wallenberg syndrome.
1) Ipsilateral: facial pain and temperature loss
2) Contralateral: limb/torso pain and temperature loss
3) Ataxia, nystagmus
Site of lesion: anterior infererior cerebellar artery
What are the associated effects?
This is also called lateral pontine syndrome.
1) Ipsilateral: facial paralysis and deafness
2) Ipsilateral: facial pain and temperature loss
3) Contralateral: limb/torso pain and temperature loss
4) Ataxia, nystagmus
What is amaurosis fugax?
Lack of blood supply to the retina (e.g. plaque or blood clot) in carotid artery causes PAINLESS and TRANSIENT sudden loss of vision (one or both eyes).
A stroke affecting which artery presents with contralateral homonymous hemianopia with macular sparing and visual agnosia?
Posterior cerebral artery lesion
A stroke affecting which artery presents with oculomotor nerve palsy (‘down and out’)?
Weber’s syndrome (branches of the posterior cerebral artery that supply the midbrain)
What is the most common cause of SAH?
Head injury
In the absence of trauma, SAH is termed what?
Spontaneous SAH
Give some causes of spontaneous SAH:
1) intracranial aneurysm (saccular ‘berry’ aneurysms)
2) arteriovenous malformation
3) pituitary apoplexy
4) mycotic (infective) aneurysms
What is the most common cause of a spontaneous SAH?
intracranial aneurysm (saccular ‘berry’ aneurysms) - accounts for 85% cases
What are some conditions associated with berry aneurysms?
- HTN
- Adult polycystic kidney disease
- Ehlers-Danlos syndrome
- Coarctation of the aorta
Classical presenting features of SAH?
1) Headache
2) N&V
3) Meningism: photophobia, neck stiffness
4) Altered consciousness
5) Focal neurological signs
6) Seizures
Describe the headache in SAH
1) usually of sudden-onset (‘thunderclap’ or ‘hit with a baseball bat’)
2) severe (‘worst of my life’)
3) occipital
4) typically peaking in intensity within 1 to 5 minutes
There may be a history of a less severe ‘sentinel’ headache in the weeks prior to the presentation
What 2 examinations can be done to help diagnose meningitis?
1) Kernig’s sign
2) Brudzinski’s sign
How do you perform Kernig’s sign?
The inability to extend the knee due to pain when the patient is supine and the hip and knee are flexed to 90 degrees
A positive Kernig’s sign is caused by irritation of motor nerve roots passing through inflamed meninges as they are under tension.
What is is brudzinski’s sign?
Severe neck stiffness causes a patient’s hips and knees to flex when the neck is flexed
How is BP affected in SAH?
HTN typically seen
1st line investigation in SAH?
Non-contrast CT head –> acute blood (hyperdense/bright on CT) is typically distributed
Next investigation in SAH if:
a) if CT head is done within 6 hours of symptom onset and is normal
b) if CT head is done more than 6 hours after symptom onset and is normal
a) consider alternative diagnosis, do NOT do lumbar puncture
b) do lumbar puncture (but perform at least 12 hours following the onset of symptoms)
If head CT in SAH is done within 6 hours, why is a LP then not indicated?
Diagnostic accuracy of CT head scans is highest within 6 hours of onset –> a negative CT does rule out SAH.
If head CT in SAH is not done within 6 hours, why is a LP then indicated?
As a lumbar pincture can then assist in diagnosis of SAH.
If not done with 6 hours, a negative CT scan does not rule out SAH so a lumbar puncture should be done 12 hours after symptom onset.
When should lumbar puncture be done in SAH?
12 hours after symptom onset - this would show the presence of xanthochromia in the CSF, making the CSF appear yellow rather than clear.
Lumbar puncture results in SAH?
1) Presence of xanthochromia in the CSF, making the CSF appear yellow rather than clear.
2) Normal or raised opening pressure
What is xanthochromia?
RBC breakdown
Next step in management of SAH if CT scan shows evidence of SAH?
Referral to neurosurgery ASAP
Management of confirmed aneurysmal subarachnoid haemorrhage?
Supportive:
1) bed rest
2) analgesia
3) VTE prophylaxis
4) discontinuation of antithrombotics (reversal of anticoagulation if present)
Complications of aneurysmal SAH?
1) re-bleeding
2) hydrocephalus
3) vasospasm
4) hyponatraemia
5) seizures
Cause of hyponatraemia post aneurysmal SAH?
SIADH
What scoring system is used to assess functional independence and was developed for use in patients after a stroke?
Barthel index
Intracranial haemorrhages, excluding stroke, mainly fall into what 3 categories?
1) Extradural
2) Subdural
3) Subarachnoid
Where does an extradural haemorrhage occur?
Occurs between the dura mater of the meninges and the skull.
What is an epidural haemorrhage often the result of?
Head trauma - particularly trauma to the pterion, leading to tearing of the middle meningeal artery.
What artery is damaged in epidural haemorrhage?
Middle meningeal artery
Clinical features of epidural haemorrhage?
1) Acute severe headache
2) Contralateral hemiplegia
3) Rapid deterioration in GCS after a lucid period
CT scan features of epidural haemorrhage?
A biconvex haematoma is diagnostic, which is limited to the skull sutures where the dura adheres to the skull.
What is a subdural haemorrhage?
Subdural haemorrhage is a bleed that occurs between the dura mater and the arachnoid mater of the meninges.
Presentation of a subdural haemorrhage?
Its presentation is typically more gradual compared to extradural haemorrhages.
- Gradually increasing headache and confusion.
- N&V
- Diminished eye, verbal, or motor response
- Focal neurological signs indicating the haematoma site.
Risk factors for subdural haemorrhage?
Age, history of head trauma, alcoholism, and anticoagulation use.
CT scan features of subdural haemorrhage?
Crescent shaped haematoma is diagnostic.
It follows the contour of the skull as it is not restricted by skull sutures.
Cause of a subdural haemorrhage?
The haematoma results from shearing forces that tear the bridging veins between the cortex and dura mater.
These forces commonly arise from minor head traumas, but can also occur spontaneously in patients with bleeding disorders, anticoagulant therapy, chronic alcohol use, and recent trauma.
What are the 4 posterior stroke syndromes?
1) Basilar artery occlusion
2) Anterior inferior cerebellar artery
3) Wallenberg’s syndrome (lateral medullary syndrome/posterior infererior cerebellar artery infarct)
4) Weber’s syndrome/medial midbrain syndrome (paramedian branches of the upper basilar and proximal posterior cerebral arteries)
Presentation of wallenberg’s syndrome (lateral medullary syndrome)?
What artery is affected?
Infarct: posterior inferior cerebellar artery
Features:
- Ipsilateral Horner’s syndrome
- Ipsilateral loss of pain & temp sensation on face
- Contralateral loss of pain & temp over contralateral body
Presentation of Weber’s syndrome/medial midbrain syndrome (paramedian branches of the upper basilar and proximal posterior cerebral arteries)?
- Ipsilateral oculomotor nerve palsy
- Contralateral hemiparesis
What type of haemorrhage can alcoholism predispose to?
Subdural
Presentation of CSF post SAH?
Pink or yellow coloured (due to xanthochromia)
Presentation of Wallenberg syndrome (lateral medullary syndrome)?
Mneumonic: DANVAH
Dysphagia, ipsilateral Ataxia, ipsilateral Nystagmus, Vertigo, Anaesthesia (Ipsilateral facial numbness and contralateral pain loss on the body) and ipsilateral Horner’s syndrome
What drugs can cause haemorrhagic stroke?
sympathomimetic drugs (such as cocaine and amphetamines)
After thrombolysis in strokem management, when should aspirin be taken?
Aspirin 300mg after 24 hours from alteplase
