Stroke + TIA Flashcards
What are generalised causes of interrupted O2 supply
Low O2 in blood
Inability to use O2
Inadequate supply of blood
What causes low O2 in blood
CO poisoning
Drowning
Respiratory arrest
What causes Inability to use O2
Cyanide poisoning
What causes inadequate blood supply
MI
Hypotension
What causes a zonal / watershed patter of infarction
Hypotension
Central arteries will be perfused
Other areas poorly perfused
What causes cortical necrosis
MI
What causes localised / focal interruption to 02 supply
Atheroma
Thromboembolism
Ruptured aneursym
Arterial dissection / venous sinus thrombosis = rare
What is a stroke
Focal neuro deficit of sudden onset due to disruption of blood supply to the brain
>24 hours
Causes infarction as brain = aerobic metabolism
What are two types of stroke
Ischaemic (85%)
Haemorrhagic
- ICH = most common
- SAH can cause 5%
ANATOMY OF CIRCULATION
ICA Gives of Retinal Then ACA then MCA MCA most affected atherosclerosis Retinal if embolic 2 vertebral arteries (posterior brain) Give of basilar and cerebellar
What causes ischaemic stroke
Large atherothromboembolism or small vessel
Cardioembolic - AF / IE / MI
Rare Carotid dissection / trauma Venous sinus thrombosis Hypercoagulable state Sickle cell
What causes haemorrhage stroke
HYPERRTENSION Ruptured aneurysm Vessel spasm AV malformation Tumour Anti-coagulation / thrombolysis
What are causes of stroke in the young
Carotid artery dissection = always consider Vasculitis SAH Venous sinus thrombosis Anti-phospholipid syndrome
DDX of stroke
Head injury Severe migraine Hypo or hyperglycaemia - always exclude Metabolic - hyponatraemia Facial nerve palsy Subdural Tumour Weirnecke's encephalopathy Hepatic encephalopathy Encephalitis Abscess Drug overdose Vestibular disorder Transient global amnesia Demyelination Neuropathy Functional Sx
What are RF for ischaemic stroke
Age Male Hypertension = most important modifiable RF Previous stroke or TIA Smoking High cholesterol DM Hypercoagulable Vasculitis OCP FH Alcohol Obesity Poor cardiac / established CVD disease AF for cardioembolic
What are RF for haemorrhagic stroke
Age Hypertension AV malformation Anti-coagulant Thrombolysis
Atheroma RF
High BP
High cholesterol
Smoking
DM
What causes thrombosis
Change in vessel wall
Change in blood constituents
Stasis of blood flow
RF for AF
P - pulmonary disease / pheochromocytoma I - IHD R - rheumatic fever / MS / MR A - anaemia / age T - thyrotoxicosis E - elevated BP / ethanol S - sepsis / sleep apnoea
When are signs of stroke worse
At onset
Then begin to improve
What investigations do you do in all patients presenting with stroke to ED
Vitals inc BP (often high)
Neuro exam
Bloods
ECG
CXR
Non-contrast CT = 1st line imaging to exclude haemorrhage ASAP
MRI = better at showing infant (but not in 1st stages)
What bloods
FBC, U+E, LFT, lipids, glucose, ESR, coagulation
Preg test, LFT and toxicology in selected patient
Why do you do ECG
Look for AF / ischaemic changes
If AF - may want to do ECHO
Why do you do imaging and when
EXLUDE BLEED To see if suitable for thrombolysis CT if - Thrombolysis indicated - On anti-coagulant - Bleeding tendency - GCS <13 - Unexplained progressive / fluctuating symptoms - Papilloedema / stiff neck / fever - Severe headache at onset
What is FAST
Face Arms / legs - loss of power./ sensation Speech - lost / disturbed Loss of vision Loss of coordination / balance
What are common visual problems in stroke
Hemianopia or diplopia
If whole eye affected tends to be retinal problem
Vertical nystagmus if cerebellar
What score is used for assessment
ROSIER
What must you do before ROSIER
Exclude hypoglycaemia
What does ROSIER Include
- ve 1
- LOC
- Seizure at onset
- Syncope
+1
- Asymmetric arm weakness
- Asymmetric leg weakness
- Speech disturbance
- Visual field defect
When is a stroke likely
If >0
What do you do if patient presents 6 weeks after event
Carotid doppler of both carotids Put on secondary prevention Endarectomy if >70% stenosis If 100% then no chance of emboli Can do CTA or MRA to look for aneurysm
What are the guidelines for TIA / non-disabling stroke
BMT
Carotid imaging within 1 week
If not significant stenosis
Continue BMT
If significant >70% + symptomatic (TIA / stroke / amuorosis fujax)
Refer for endarectomy
If no operation 1 in 5 = stroke
1 in 100 chance if operation
What other tests can be done after stroke to look for cause
Carotid dopper = 1st line CXR 24 hour ECG to look for AF ECHO Hyper-coagulable blood screen Cerebral angiogram
What is the immediate Rx of stroke
ABCDE management
- Dehydration common and should be treated with bolus
- Avoid overload as will exacerbate cerebral oedema
Immediate CT to exclude haemorrhage
Aspirin 300mg once haemorrhagic excluded with CT (withhold if getting thrombosis)
Continue anti-platelet
Maintain BP, fluid, O2 and temp
Only treat BP if hypertensive emergency as may impair perfusion e.g. encephalopathy, MI or dissection, PET or thrombolysis - want <185 as may impair perfusion or haemorrhage with BP >200
Protect airway as risk of hypoxia + aspiration
Avoid hyperglycaemia as poor prognosis
Screen swallow - NBM till assessed
Involve stroke team = very important
What is 1st line in ischaemic stroke
Thromboylsis + Thrombectomy If within 4.5 hours
When do you do thrombosis
If admitted within 4.5 hours of ischaemic stroke
Must do CT first to exclude haemorrhage
If >4.5 = stroke team as tissue dead
What is 1st line thrombosis agent
Alteplase (tisse plasminogen activator which breaks down plasminogen to plasmin which breaks down clot)
What do you do post thromboylsis
CT to look for bleed
When can you offer thrombectomy
If within 6 hours
Confirmed anterior circulation stroke by CTA or MRA
Possibly if posterior
Can extend 6-24 hours if imaging shows can salvage tissue
What are absolute CI to thrombolysis
Symptoms improving Symptoms >4.5 hours Haemorrhage on brain imaging Previous ICH Seizure at onset Intracranial neoplasm Minor neuro deficit or rapid improvement e.g TIA Prior stroke or traumatic brain injury within 3 months Symptoms suggesting SAH even if CT normal LP within 7 days Active bleeding Varices GI haemorrhage within 3 week Pregnancy Uncontrolled BP >185 Platelet <100 INR > Blood glucose <50 or >400
What are relative CI
Patient on anti-coagulant - Warfarin / heparin Bleeding disorder Low platelet Low or high BG <16 or >80
What is given as secondary prevention after stroke
Aspirin 300mg for 2 weeks Then start anti-platlet Carotid endarectomy >70% stenosis Anti-hypertensive Statin if cholesterol
What is 1st line anti-platelet
Clopidogrel (ADP antagonist)
What is given if clopidogrel CI
Aspirin (thoromboxane A2 inhibitor) high dose +
Dipyramidole inhibitor
What do you do if AF post stroke
DO NOT restart anti-coagulation until CT excluded haemorrhagic and 14+ days since ischaemic
Warfarin or DOAC
Do you go on anti-platelet if on anti-coagulant
No
Only if needed for other co-morbid
What do you do for haemorrhagic stroke
Neurosurgeon
Craniotomy to give space
Stop and reverse anti-coagulant
Lower BP
What is the Oxford classification of stroke
Assess for initial signs of Unilateral hemiparesis Unilateral sensory loss Of face / arm or leg Homonymous hemianopia Higher cognitive dysfunction e.g. dysphasia
What are the types of stroke
TACS - total anterior
PACS - partial anterior
LACS - lacunar
POCS - posterior
What artery affected in TACS
MCA and ACA
What part of criteria fulfilled
ALL 4 Motor loss in 2 / 3 Sensory loss Must have hemianopia \+ cognition - dysphagia / neglect NO BRAIN STEM
What artery affects in PACS
Smaller arteries of anterior circulation / MCA
What part of criteria filled
At least 2+ Motor loss Sensory loss One of hemianopia or cognition - dysphasia / neglect No brain stem
What artery affected in lacunar
Arteries around basal ganglia / thalamus
What criteria fulfilled
1+ of
Motor / sensory loss
Can be pure sensory
Ataxia hemiparesis
NO hemianopia / dysphasia / neglect or brains stem
What arteries in posterior stroke
Vertebrobasillar
What part of criteria filled
1+ of cerebellar or brain stem Sx
Motor loss
Sensory loss
Hemianopia +- dysphasia + -neglect
What is a TIA
Ischaemic stroke <24 hours
New definition = tissue based
Due to reversible ischaemia so not permanent
NO INFARCTION
What causes TIA
Main causes
Atherothrombembolism
Cardiombolism post MI / AF
Other Dissection Hyperviscosity e.g. polycytheaemia / myeloma Sickle cell Vasculitis
What is the DDx
Hypoglycaemia
Migraine + aura
Focal epilepsy
Retinal bleed
What does crescendo TIA suggest
Critical stenosis of artery
What do you do if suspected TIA
Neuro exam Vital signs FBC, ESR, U+E, glucose, lipids Imaging to exclude haemorrhage - MRI better for TIA - images posterior better and acute ischaemia
What do you do for cause
CXR
ECG
ECHO
Hyper-coagulbale screen
What are the guidelines TIA / non-disabling stroke
Same
What do you do if suspected TIA
Aspirin 300mg unless CI
- Anti-coagulant
- Bleeding disorder
- Already on aspirin 75mg - continue until review
Risk of stroke = highest first 48 Horus
Admit for CT and to exclude haemorrhage if on anti-coagulant
Stroke specialist within 24 hours
If TIA suspected within last 7 days
Urgent assessment within 24 hours
Give aspirin 300mg if symptoms fully resolved
If >7
Still refer within 7 days
If 1+ or severe stenosis
Discuss need for admission with specialist as crescendo
What do you post
Control CVS RF - BP / cholesterol / DM / smoking
Same as stroke
Aspirin 300mg 2 weeks - If already on non benefit
Clopidogrel 75mg
Control BP
Anti-coagulant if suspect AF
Perform ABCD2 score
What does TIA suggest
Increased risk of stroke
What is important to remember for stroke
Rapid onset Depends on part of brain affected Abnormal movement unusual \+ve visual Sx more likely to be migraine Severe headache is unusual
If a stroke in <55 what investigations for cause
Thrombophilia and autoimmune screen
MRI outpatient
Holter for AF
What score is used in TIA to estimate risk of stroke
ABCD2 Age >60 BP >140/90 Clinical features Duration DM
If score >4 = aspirin 300mg + specialist within 24 Horus
What do you give with Aspirin
PPI if indicated
How may carotid stenosis present
Carotid bruit
1st line = doppler USS in all patients with TIA
If >70% stenosis = endarectomy within 7 days unilateral unless both >70%
What is a penumbra
Area around infarcted tissue which is hypo-perfused
May be saved if reperfused
Common cause of stroke in the young
Carotid artery dissection
What is known precipitating factor
Head or neck trauma
Aneurysm / HTN and atherosclerosis also indicated but consider dissection if no known CVS RF
How does it present
Ipsilateral headache
Face or neck pain
Horner’s
25% can have neck pain alone - sudden severe and persistent
How do you Dx
CTA OR MRA
How do you Rx
Usually resolves
If posterior bleed noticed on CT what is needed
Neurosurgery
Why can posterior strokes be difficult to Dx
Similar to benign
BPPV
Labrynthitis
What are important symptoms to distinguish
Vertical nystagmus
Vomiting
Diplopia
Who always gets a CT gif TIA
If on anti-coagulant to exclude haemorrhage
