Stroke Flashcards
A 50 year old man presents to the ED arriving in an ambulance with a 2 hour history of sudden onset left hemiparesis (left arm, leg, and facial droop). It was witnessed by his daughter. The patient has a history of HTN and Dyslipidemia.
State your differentials (Give 4)
What is your initial investigation?
Stroke
Hypoglycemia
Seizure
Hemiplegic migraine
Functional disorder
Initial investigation = Non-contrast CT brain
Define Stroke
What is the etiology of stroke along with the relevant causes/RFs?
Stroke is the rapid loss of brain function due to disturbance of blood supply. It may be:
1) Hemorrhagic: Aneurysms, HTN, AV malformation (dural AV fistula/ venous sinus thrombosis = causes of SAH (without trauma ofcourse)
2) Ischemic: Can be thrombotic (atherosclerosis) or Embolic (A.FIB, prosthetic valve, recent MI, atherosclerosis)
What is the most common artery of insult causing stroke?
Disturbance of blood supply in this artery causes what symptoms?
Middle cerebral artery
Hemiparesis, hemianesthesia +/- aphasia (if dominant hemisphere)
Give the clinical presentation of Stroke
Sudden onset focal neurological defect variable depending on artery:
ACA: Upper limb weakness bilaterally
MCA: Hemiparesis, hemianesthesia +/- aphasia (if dominant hemisphere)
PCA: Homonymous Hemianopia +/- Vertigo
PICA: Lateral Medullary syndrome
=>If posterior circulation it is both Homonymous hemianopia + lateral medullary syndrome
What causes Horner’s syndrome? (Give 4/5 for 5/5)
How does it present?
Horner’s syndrome is caused by a disruption in the SNS
1) Brachial Plexus Injury
2) Carotid Artery Ischemia (PICA) => Lateral Medullary Syndrome
3) Apical Lung Tumour (similar to brachial plexus)
4) Migraine
5) Multiple sclerosis
Presents with Triad of Ptosis, Miosis, and facial Anhidrosis
What is ptosis?
eyeline drooping
What is Miosis?
Constricted pupil
What is anhidrosis?
not sweating, dry
Obstruction to which artery may lead to Horner’s Syndrome?
Which artery does it come from?
Obstruction of the same artery may cause another syndrome. What is it and give its symptoms.
PICA: Posterior inferior cerebral artery
Vertebral artery
Lateral Medullary Syndrome: Horner’s (Ptosis, miosis, facial anhidrosis), Diplopia, slurred speech, dizziness (vertigo)
A patient with a suspected stroke presents to the ED. What investigations (imaging) will you perform to confirm the cause of the stroke and why for each.
Non-contrast CT brain initially to exclude hemorrhage as a contraindication for CT angio and thrombolysis
This is followed by CT angio which will locate the aneurysm and assess need for thrombectomy.
What is the definitive treatment for stroke?
IV thrombolysis +/- Thrombectomy
What is the cutoff for administration of thrombolysis in a stroke patient?
Cutoff = 4.5 hours from onset of symptoms!!! because the risk of hemorrhage outweighs the benefit of thrombolysis
What drug is given during thrombolysis?
What class of drugs is it?
How is it given in a case of stroke (given no contraindications)
Alteplase
tPA: tissue plasminogen activator
IV Alteplase 0.9mg/kg up to a maximum of 90mg => if >100kg just give 90
Given 10% as bolus and 90% as infusion over 1 hour
What are the 2 most common cranial arteries to have large vessel occlusionn in stroke?
MCA
Internal carotid (bifurcation)
What is the procedure for thrombectomy?
What is the cutoff for conducting a thrombectomy for a stroke patient?
What is the indication for a thrombectomy?
What are the complications of thrombectomy?
Similar to Aneurysm coiling: Patient under GA, sheath placed in femoral artery -> Guide catheter moves up to common carotid/VERTEBRAL arteries -> microcatheter and microwire to access occluded vessel -> Deploy clot retrieval device
12 hours
Indication = Large vessel occlusion
Complications: puncture/failure => bleeding, groin bleeding/vessel damage from femoral sheath, death