Ischaemic stroke is the most common cause of stroke (78%). For a patient who presents with stroke, thrombolysis +/- thrombectomy should be considered as soon as hemorrhagic stroke is ruled out.
Presentation of ischemic stroke (in order of increasing severity)
| Cause | Presentation |
|---|---|
| Thrombotic small vessel disease (lacunar) | Milder symptoms, absence of cortical deficits (aphasia, neglect or field cut), <1.5 cm diameter lesion on MRI and subcortical lesions |
| Thrombotic large vessel disease | Preceding TIA, evidence of large vessel stenosis, and vascular risk factors |
| Cardioembolic stroke | Maximal deficit at onset, severe deficits, large zone of infarct and infarction of multiple vascular territories |
| Hypercoagulability | Young patient, history of thromboembolism, late miscarriages, pro-thrombotic drugs, symptoms compatible with SLE or occult malignancy |
- Causes of ischaemic stroke
- Thrombotic large vessel disease
- Atherosclerosis (intracranial or extracranial vessels)
- Thrombotic small vessel disease (lacunar)
- Lipohyalinosis
- Microatheromas
- Microembolism
- Cardioembolic
- Atrial fibrilation
- Left atrial thrombus
- Left ventricular thrombus
- Valvular disease
- Structural heart disease (dilated cardiomyopathy)
- Paradoxical embolus through patent foramen ovale
- Aortic arche plaque
- Cardiac tumors
- Rare causes
- Arterial dissection
- Sickle cell disease
- Hypercoaguable state
- Vasculitis
- Vasospasm (SSRIs and Cocaine)
- Venous sinus thrombosis
- Genetics (CADASIL)
- Complicated migraine
- Cryptogenic or embolic strokes or undetermined source (ESUS)
- Thrombotic large vessel disease
- Treatment
- The goal is to restore blood flow
- Thombolysis with tPA (alteplase)
- Onset within 3 – 4.5 hours in patients < 80 years without a history of stroke and not on anticoagulants.
- Best results are seen within 90 minutes.
- Mechanical thrombectomy
- Onset more than 4.5 hours Benefitial for large artery occlusion in the proximal anterior circulation
- Contraindications for tPA (either currently bleeding or likely to bleed)
- Active bleeding
- Recent stroke or serious head injury in last 3 months
- BP > 185/110 despite treatment
- Recent invasive surgical procedure in the last 2 weeks
- Gastrointestinal or Genitourinary bleed in the past 21 days
- Platelet < 100,000/mm3
- INR > 1.7
- Increased PTT if heparin was given in the preceding 48 hours
- History of intracranial neoplasm
- Coma or Stupor
- Bleeding diathesis