Revision - TIA, Stroke & SAH Flashcards
What are 3 exceptions to giving 300mg aspirin immediately in TIA?
1) Pt taking anticoagulant or has a bleeding disorder –> needs immediate assessment/imaging for haemorrhage
2) Pt already taking low dose aspirin –> continue this dose until specialist assessment
3) Aspirin contraindicated
Referral for patients who have had a suspected TIA in the last 7 days?
Urgent assessment by specialist (within 24h)
Referral for patients who have had a suspected TIA which occurred more than 7 days ago?
Assessment by specialist within 1 week
What imaging is indicated in a TIA?
MRI
When is a carotid doppler not indicated in TIA?
If they are not a candidate for carotid endarterectomy
2ary prevention following TIA? (2)
1) antiplatelet therapy to follow on from initial aspirin therapy: clopidogrel
2) atorvastatin (20-80mg daily)
What is 1st line antiplatelet in 2ary prevention of TIA?
Clopidogrel 75mg OD
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?
Reduce non-HDL cholesterol by 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.
ONLY if carotid artery stenosis >70%
What is the most important risk factor of a haemorrhagic stroke?
HTN
What are the 2 types of haemorrhagic stroke?
1) Intracerebral
2) Subarachnoid
What are the 2 main subtypes of ischaemic strokes?
1) Thrombotic
2) Embolic (AF is an important cause)
What classification is used in stroke?
Oxford Stroke Classification (also known as the Bamford Classification).
This classifies stroke based on 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 criteria from the Oxford Stroke Classification are present in a partial anterior circulation infarct?
2/3 criteria
OR
higher cerebral dysfunction alone
What arteries are involved in a lacunar infarct?
Perforating arteries around the internal capsule, thalamus and basal ganglia.
How does a lacunar infarct present?
With 1 of the following:
1) Unilateral weakness (and/or sensory deficit) of face and arm, arm and leg or all 3
2) Pure sensory stroke
3) Ataxic hemiparesis
What arteries are involved in a posterior circulation infarct?
Vertebrobasilar arteries
Presentation of a posterior circulation infarct?
Presents with 1 of the following:
1) Cerebellar or brainstem syndromes
2) LOC
3) Isolated homonymous hemianopia
Initial mx of an ischaemic stroke?
1) Neuroimaging - to exclude haemorrhagic
2) Aspirin 300mg (for 2 weeks)
3) Exclude hypoglycaemia
4) Admission to a specialist stroke centre
5) Thrombolysis with alteplase (if criteria met)
When is aspirin 300mg given in stroke?
AFTER haemorrhagic stroke excluded by CT
What is the criteria for thrombolysis in ischaemic stroke?
1) Symptom onset <4.5 hours
2) Patient has not had a previous intracranial haemorrhage, uncontrolled HTN, pregnant etc
What should ALWAYS be excluded in a suspected stroke?
Hypoglycaemia
Symptoms of a posterior stroke?
- nystagmus
- vertigo or dizziness
- N&V
- head motion intolerance
- new gait unsteadiness
If patients with stroke are unable to swallow 300mg aspirin orally, what is next option?
600mg PR
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 2 investigations can be considered?
1) Carotid artery doppler
2) ECG
Mx of AF causing ischaemic stroke?
Consider anticoagulation 14 days post stroke
Are lower or upper extremeties affected more in an anterior cerebral infarct?
Lower > upper
Are lower or upper extremeties affected more in a middle cerebral infarct?
Upper > lower
Associated effects of posterior cerberal artery infarct?
- Visual agnosia
- Contralateral homonymous hemianopia with macular sparing
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?
1) Previous intracranial haemorrhage
2) Seizure at onset of stroke
3) Intracranial neoplasm
4) Suspected SAH
5) Stroke or traumatic brain injury in preceding 3 months
6) LP in preceding 7 days
7) GI haemorrhage in preceding 3 weeks
8) Pregnancy
9) Oesophageal varices
10) Uncontrolled hypertension >200/120mmHg
11) Active bleeding
Who is thrombectomy considered in?
Considered in patients with a confirmed blockage of the proximal ANTERIOR circulation or proximal POSTERIOR circulation.
What is thrombectomy done alongside?
IV thrombolysis
What is thromboylsis done with in stroke?
Alteplase
What is alteplase?
a tissue plasminogen activator
Plasminogen is activated to plasmin –> degrades fibrin clots
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?
A type of midbrain stroke
Infarct is in branches of the posterior cerebral artery that supply the midbrain.
Associated effects of Weber’s syndrome?
1) Ipsilateral CN III palsy –> down and out eye
2) Contralateral weakness of upper and lower extremity
What arteries are affected in lateral medullary syndrome?
Posterior inferior cerebellar artery (PICA)
What is lateral medullary syndrome also known as?
Wallenburg syndrome
Site of lesion: posterior infererior cerebellar artery
What are the associated effects?
1) Ipsilateral: facial pain & temp loss
2) Contralateral: limb/torso pain and temperature loss
3) Ataxia, nystagmus
What artery is affected in lateral pontine syndrome?
Anterior inferior cerebellar artery
Site of lesion: anterior infererior cerebellar artery
What are the associated effects?
1) Ipsilateral: facial pain & temp loss
2) Ipsilateral: facial paralysis and deafness
3) Contralateral: limb/torso pain and temperature loss
3) Ataxia, nystagmus
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 - midbrain stroke (branches of posterior cerebral artery)
Give some causes of a spontaneous SAH
1) Intracranial aneurysm e.g. saccular ‘berry’ aneurysm –> most common
2) AV malformation
3) Pituitary apoplexy
4) Mycotic (infective) aneurysms
What are some conditions associated with berry aneurysms?
1) HTN
2) APKD
3) Ehlers-Danlos
4) Coarctation of the aorta
1st line investigation in SAH?
Non-contrast head CT
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) rule out SAH
b) wait until 12h after symptom onset and do LP
When should lumbar puncture be done in SAH?
12h after symptom onset
When must a non-contrast head CT be done in suspected SAH for it to be diagnostic?
Within 6 hours
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
Give some complications of SAH
1) re-bleeding
2) hydrocephalus
3) hyponatraemia
4) vasospasm
5) seizures
Cause of hyponatraemia post-SAH?
SIADH
What scoring system is used to assess functional independence and was developed for use in patients AFTER a stroke?
Barthel index
What is an epidural haemorrhage often the result of?
Head trauma - particularly trauma to the pterion, leading to tearing of the middle meningeal artery.
Clinical features of epidural haemorrhage?
1) Acute severe headache
2) Contralateral hemiplegia
3) Rapid deterioration in GCS following lucid period
Risk factors for subdural haemorrhage?
Age, alcohol misuse, anticoagulation, history of head trauma
Cause of a subdural haemorrhage?
Tearing of bridging veins between cortex and dura mater.
This can occur due to minor trauma in those with risk factors.
What are 4 posterior stroke syndromes?
1) Basilar artery occlusion
2) Anterior inferior cerebellar artery infarct
3) Posterior inferior cerebellar artery infarct i.e. Wallenburg’s syndrome, lateral medullary syndrome
4) Weber’s syndrome/medial midbrain syndrome
Presentation of Wallenberg syndrome (lateral medullary syndrome)?
Dysphagia, ipsilateral Ataxia, ipsilateral Nystagmus, Vertigo, Anaesthesia (Ipsilateral facial numbness and contralateral pain loss on the body) and ipsilateral Horner’s syndrome
After thrombolysis in stroke management, when should aspirin be taken?
Aspirin 300mg after 24h from alteplase
What can rapid correction of severe hyponatraemia cause?
Osmotic demyelination syndrome i.e. central pontine myelinolysis
What can untreated, severe hyponatraemia cause?
Cerebral oedema (and then brain herniation)
Features of osmotic demyelination syndrome?
- dysarthria, dysphagia, paraparesis or quadriparesis, seizures, confusion, and coma
- locked in syndrome
What is thrombectomy?
An exciting new treatment option for patients with an acute ischaemic stroke.
When is thrombectomy indicated in an ischaemic stroke?
Within 6h of symptom onset
in people with confirmed occlusion of the PROXIMAL ANTERIOR circulation
When can an extended target time of 6-24 hours be considered for thrombectomy?
Who have acute ischaemic stroke and confirmed occlusion of the proximal posterior circulation (that is, basilar or posterior cerebral artery)
IF
if there is the potential to salvage brain tissue
What is a headache, fever & focal neurology suggestive of?
Brain abscess
What arrhythmia can SAH cause?
Torsades de pointes (can deteriorate into ventricular fibrillation).
How can SAH cause torsades de pointes?
Due to a sudden catecholamine release in response to the acute hemorrhage
What is BNP?
A hormone produced mainly by the left ventricular myocardium in response to strain.
Give some causes of a raised BNP
1) HF
2) Any cause of LV dysfunction e.g. myocardial ischaemia or valvular disease
3) Reduced excretion e.g. CKD
What does a NNT of 20 mean in a prevention study?
20 patients would need to be treated to prevent 1 event.
E.g. for 1000 patients treated, there would be 50 fewer events.
Mx of TIA due to AF
Following a TIA, anticoagulation for AF should start IMMEDIATELY once imaging has excluded haemorrhage
i.e. lifelong apixaban
Mx of ischaemic stroke due to AF?
Aspirin for 2 weeks
Anticoagulation after this
What artery is affected in amaurosis fugax?
Retinal/opthalmic artery
What is the central retinal artery a branch of?
Ophthalmic artery (this is a branch of the internal carotid)
What is a broad complex following an MI almost always due to?
VT
What is the first line radiological investigation for suspected stroke?
Non-contrast head CT
What BP is an absolute contraindication to thrombolysis in an acute ischaemic stroke?
≥185/110
Lower BP first
What can be seen on an ECG in acute pericarditis?
Widespread ST elevation
What artery is affected:
- Contralateral hemiparesis and sensory loss with the upper extremity being more affected than the lower
- Contralateral homonymous hemianopia
- & aphasia
Middle cerebral artery
How does pontine haemorrhage commonly present?
- reduced GCS
- paralysis
- bilateral pinpoint pupils
What is the preferred antiplatelet for secondary prevention following stroke?
Clopidogrel
What 2 classes of drugs are at most risk of causing medication overuse headache?
Triptans & opioids
What is Chagas’ disease?
caused by the protozoan Trypanosoma cruzi.
What is the most frequent and most severe manifestation of chronic Chagas’ disease?
Cardiomyopathy
A seizure causing post-ictal dysphasia is associated with what lobe?
Temporal
What type of seizure is a ‘complex’ febrile convulsion?
Focal seizure
Give 2 contraindications for bupropion (smoking cessation medication)
1) Epilepsy - lowers seizure threshold
2) Pregnancy & breastfeeding
What score categorises patients into levels of frailty according to their function?
Rockwood frailty scale
What is the preferred imaging modality in patients with suspected TIA?
MRI brain with diffusion-weighted imaging
What is autonomic dysreflexia?
Clinical syndrome that occurs in patients who have had a spinal cord injury at, or above T6
- extreme HTN (can lead to haemorrhagic stroke) W
- flushing
- sweating above level of cord lesion
- agitation
What is the best assessment tool for differentiating between stroke and stroke mimics?
The Recognition of Stroke in the Emergency Room (ROSIER) scale
What type of dopamine receptor agonists are most associated with pulmonary, retroperitoneal & cardiac fibrosis?
ergot-derived dopamine receptor agonists (bromocriptine, cabergoline)
What type of dementia is MND most associated with?
Frontotemporal dementia
What 2 types of dementia is parkinsonism associated with?
1) parkinson’s dementia
2) LBD
Cause of bilateral vs unilateral foot drop?
Bilateral –> peripheral neuroapthy
Unilateral –> common peroneal nerve lesion
Does domperidone exacerbate Parkinson’s symptoms?
No - doesn’t cross BBB
What is the preferred antiemetic in parkinson’s disease?
Domperidone
What drug has the strongest evidence base for reducing relapse in multiple sclerosis?
Monoclonal antibodies such as natalizumab
What branches does the basilar artery give off?
Pontine arteries
When should statins be started after stroke?
48h after stroke onest in those not already taking a statin
Does the absence of oligoclonal bands in the CSF exclude a diagnosis of MS?
No
What type of nerve fibres transmit signals slowly and produce dull and diffuse pain sensations?
C fibres
What surgical procedure may be used to treat myasthenia gravis?
Thymectomy
What medication may be used to slow the progression of the disease and extend survival by several months in amyotrophic lateral sclerosis (ALS)?
Riluzole
What is the usual first-line prophylactic treatment for chronic or frequent tension headaches?
Amitriptyline
What cholinesterase inhibitor prolongs the action of acetylcholine and improves symptoms in myasthenia gravis?
Pyridostigmine
What type of receptor do triptans stimulate?
5-HT receptors (serotonin receptors)
What type of nerve fibres transmit signals fast and produce sharp and localised sensations?
A delta fibres
What medication may be used to prevent vasospasm in subarachnoid haemorrhage?
What is the mechanism of action of this drug?
Nimodipine
CCB
What threshold is used for defining chronic versus acute pain?
> 3m duration
What dose of oxycodone is approximately equivalent to 10mg of oral morphine?
6.6mg
What term refers to when pain is experienced with sensory inputs that do not normally cause pain (e.g., light touch)?
Allodynia
What dose of tramadol is approximately equivalent to 10mg of oral morphine?
100mg
What type of medication is taken alongside levodopa and slows the breakdown of the levodopa in the brain, extending the effective duration of the levodopa?
COMT inhibitors (e.g. entacapone)
What medication is used first-line to treat relapses of multiple sclerosis?
Methylprednisolone
What are the most common antibodies found in patients with myasthenia gravis?
Acetylcholine receptor (AChR) antibodies
What type of benign tumour is associated with neurofibromatosis type 2?
Schwannoma
Which TB med can cause peripheral neuropathy?
Isoniazid
What gait disturbance may be seen in Charcot-Marie-Tooth disease? (1)
High stepping gait (due to foot drop)
Which medication is used to treat the symptoms of Lambert-Eaton myasthenic syndrome?
Amifampridine
What vitamin may be beneficial in treating migraines?
Who should avoid supplementing with this?
Vitamin B2 (riboflavin)
Patients who are pregnant or planning pregnancy
What type of benign tissue growth is associated with tuberous sclerosis? (1)
Hamartomas
What is the mechanism of action of amantadine used to treat Parkinson’s disease? (1)
Glutamate antagonist
What special test is used to support a diagnosis of myasthenia gravis?
Edrophonium test
What is the first-line medical treatment for Guillain-Barré syndrome?
IV immunoglobulins
What is the main side effect of long-term use of levodopa?
Dyskinesia
What is the first-line imaging investigation in patients with a suspected brain tumour?
MRI
What condition can cause features of Parkinsonism associated with autonomic dysfunction and cerebellar ataxia?
Multiple system atrophy
What are the mechanisms of action of tramadol? (2)
Serotonin and norepinephrine reuptake inhibitor (SNRI)
Opioid receptor antagonist
What investigation is done at the same time as a LP in meningitis?
Why?
Blood glucose for comparison to the CSF glucose
