Stroke

Strokes happen when the brain cannot get enough blood to a part of the brain due to a vascular problem. There are 3 main types of strokes:

• Ischemic (2 subtypes) - 75% of the time
  • Embolic
    • Occlusion caused by something, not from the brain 
    • Causes 
      • Afib plaque 
      • Carotid artery plaque 
      • Vegetation from heart valves
    • Risk factors 
      • Obesity 
      • Smoking 
      • Hypertension 
      • Dyslipidemia 
      • Diabetes 
      • Age 
      • Infection 
  • Thrombotic 
    • 
    • Occlusion in the blood vessel
    • Brain parts distal to the occlusion will die off 
    • Caused by a plaque (similar to an MI) 
    • Risk factors 
      • Obesity 
      • Smoking 
      • Hypertension 
      • Dyslipidemia 
      • Diabetes 
      • Age 
• Hemorrhagic (intracerebral) - 25% of the time 
  • Poor outcome 
  • Will require a neurosurgeon 

Pathophysiology 

Strokes can affect one or multiple of the arteries within the circle of Willis. 

• Anterior cerebral artery (ACA)
  •  Lower limbs 
• Middle cerebral artery (MCA) 
  • Upper limbs 
  • Face
  • Speech
• Posterior cerebral artery (PCA)
  • Visual cortex 
  • Balancing
  • Syncope 

Patients who end up with strokes tend to have common presentations. These are the following:

• Vasculapaths
• Patients with afib
  • Often not on anticoagulation 
• Young women post-trauma
  • Neck pain with a focal neurologic concussion 
• Patients with a thunderclap headache 
  • Worst headache of life with sudden onset 
  • Sometimes seen with Cushing's syndrome 
    • Bradycardia 
    • Hypertension 
    • Herniation soon to follow 

Management

When a patient suspected to have had a stroke presents to the ED the first test that is needed is a non-contrast CT scan of the brain. This scan is quicker than contrast CT and helps to see blood. If blood is seen on CT, then this is a hemorrhagic stroke. If there is no stroke, then this is an ischemic stroke. 

Picture 1. Intracranial hemorrhage on a non-contrast CT brain

• Hemorrhagic stroke - poor outcome 
  • Lower blood pressure 
  • Call neurosurgery 
    • Endovascular hemorrhage 
    • Clip
    • Craniotomy - remove the skull to reduce the intracranial hemorrhage 
  • Administer free frozen plasma 
    • Only helps if the INR is high 
• Ischemic stroke
  • tPA 
    • Used to dissolve clots 
    • Indications 
      • Non-hemorrhagic stroke newer than 3 hours for diabetics, 4.5 hours for non-diabetics (neurologists can override these) 
      • Time starts from last time seen well (if you slept at 10 pm, by morning time no tPA)
    • Contraindications 
      • Previous hemorrhagic strokes 
      • Risk of bleeding (watch for GI bleeds) 
      • Less than 2 weeks from a surgery
    • Acute management if no tPA 
      • Antiplatelets 
        • ASA 325mg 
      • Control of diabetes 
        • Avoid hypoglycemia especially 
      • Permissive hypertension 
        • 220/120
        • Maintains tissue perfusion in the brain 
    • Chronic management
      • Low molecular weight heparin 
      • Anticoagulation if afib or aflutter present 
      • ASA 81 daily and possible add dipyridamole
      • High potency statins 
        • Atorvastatin 
        • Rosuvastatin 
      • Hemoglobin a1c should be under <8%
      • Control blood pressure 
      • Lifestyle changes 
        • Stop smoking 
  • ECG/Telemetry/Holter monitoring
    • Check for arrhythmias
    • Afib or aflutter 
      • This means a CHADs2 score of 2 or higher 
        • 
      • Anticoagulation 
      • Warfarin 
        • No need to bridge with heparin
      • NOACs
  • Transthoracic echo 
    • Thrombus can be seen 
      • Warfarin
        • Will need a heparin bridge 
      • NOACs
  • Carotid U/S
    • Carotid artery stenosis
    • If stenosis <70% with no symptoms 
      • Treat medically 
    • If stenosis >80% or greater than 70% stenosis with symptoms 
      • Carotid endarterectomy (within 2 weeks) or stenting (for sicker patients)