Vascular Neurologic Disorders

Question 1

Stroke Overview

Answer 1

• Definition:
  
  • the sudden occlusion rupture of cerebral arteries or veins resulting in focal cerebral damage and clinical neurologic deficits that persist for >24 hours
• Risks:
  
  • women,genetics,HTN, cardiac disease, tobacco, high cholesterol/fat, prior TIA, carotid stenosis, DM,black Americans (x), Hispanic (early stroke), Hawaiians/American Indians/Asian-Americans are more likely to die
• S/sxs:
  
  • Cerebellar: ataxia, vertigo, balance problems, nystagmus, herniation
  • Brainstem: more severe cranial nerve dysfunction, ataxia, weakness, altered LOC, crossed motor & sensory deficits
• PE:
  
  • -ABCs
  • -Rapid assessment of deficits: Cincinnati Stroke Scale
  • -History: last time seen normal, pertinent medical history
  • -Rapid decision on plan of care
  • Time when last seen normal (time of onset)!!! → very important to determine in the history
• Dx:
  
  • Cincinnati Stroke Scale:
    
    • 1. facial droop,
    • 2. abnormal speech,
    • 3. arm drift;
    • ⅓+ is abnormal → probability of stroke = 72%
  • CT Scan: sensitive for blood, mass lesions, swelling → ischemic changes generally not visible for 6 hours
  • MRI Scan: more sensitive to ischemia and infarct, but time consuming and may not be available → typically not a first line study
  • STAT Labs:
    
    • -Fingerstick blood sugar
    • -CMP, CBC with platelets, coags, troponin
    • -hCG, tox screen
    • 12 leek EKG
    • CXR
• Tx:
  
  • Leading cause of adult disability & 5th leading cause of death. Strokes cause permanent damage → so early intervention is key to minimize damage
• Public Awareness:

FAST

• Face: looks uneven
• Arm: one arm hanging down
• Speech: slurred
• Time: call 911 now

Question 2

Ischemic Stroke

Answer 2

• Pathophys:
  
  • occlusion of cerebral artery by a clot. 85% of strokes
• Etiology:
  
  • -Thrombotic stroke: ⅔ of ischemic strokes
  • -Cardioembolic stroke: afib or atherosclerosis
  • -Carotid Dissection: release emboli & compress outflow to other arteries
  • -Intracranial Dissection: rare, 10-25% of strokes in young/middle-aged patients
  • -Other: hypoperfusion, hypercoagulability, inflammatory disorders
• S/sxs:
  
  • *New, sudden onset of:
    
    • -weakness: extremities & facial muscles (Very RARELY painful, way to differentiate b/w ischemic & hemorrhagic)
  • -Numbness
  • -Vision change: vision loss, diplopia
  • -Dizziness, vertigo, loss of balance
  • -Aphasia: receptive or expressive
  • -Agnosia: impaired sensory
  • -Apraxia: impaired motor planning (“touch your nose, touch my hand”)
• PE:
  
  • may appear normal at first glance → need to do a detailed exam to reveal focal findings
• Dx:
  
  • CT scan without contrast: to r/o a hemorrhagic stroke, ischemic changes not visible for ~6 hours
  • -MRI: more sensitive to ischemic & infarct, time consuming, not 1st line
  • -Finger stick blood sugar
  • -BMP, CBC, coags, troponin
  • -Consider beta-hCG & tox screen
  • -EKG
  • -CXR
  • -US/MRI/Angiogram: to check the carotid arteries
  • -Lipids, hgb A1C
• Tx:
  
  • Thrombolytic: Alteplase (aka tPA: tissue plasminogen activator: converts plasminogen to the enzyme plasmin → lyses fibrin & fibrinogen) within 3 hours of symptoms onset for FDA approved tx (within 4.5 hours in certain med centers, but not FDA approved tx), Tenecteplase (in stage 3 clinical trial now)
    
    • → indications:
      
      • -Age 18+
      • -dx of ischemic stroke with neuro deficit
      • -time of stroke sxs within 3 hours
      • -no exclusion criteria present
  • Endovascular Therapy: within 6 hours of symptom onset (after 8 hours in posterior circulation strokes); indicated for moderate-large stroke with a retrievable clot (can be used in combo with thrombolytics)

Question 3

What are exclusion criteria for using thrombolytics in the event of an ischemic stroke?

Answer 3

*Thrombolytic exclusion: intracranial hemorrhage on CT or clinical presentation of SAH (with normal CT), internal bleeding or trauma, spinal surgery/head trauma, stroke in last 3 months, multi-lobar infarct, uncontrolled HTN (185/100), witnessed seizure, hx of neoplasm, aneurysm, AVM

Question 4

How do you prevent complications associated with after a pt has a stroke?

Answer 4

NPO until swallow screen passed, prevent dehydration/malnutrition, rehab consult, DVT/PE prophylaxis, antiplatelet medication by day 2 (aspirin, clopidogrel, P2Y12 receptor inhibitors), anticoag if stroke d/t afib

Question 5

Hemorrhagic Stroke

Answer 5

• Definition:
  
  • atraumatic bleeding from a weakened spot on a blood vessel. 15% of strokes
• Location:
  
  • Subarachnoid: bleeding into subarachnoid space &/or ventricles
  • -Intracerebral: bleeding into brain tissue, Risk factors include HTN & anticoag use
• Etiology:
  
  • Aneurysm, arteriovenous malformation (AVM)
• S/sxs:
  
  • Subarachnoid Hemorrhage:
    
    • -Sudden onset of worst headache of patient’s life “thunderclap HA”
    • -Neck stiffness & rigidity
    • -altered LOC
    • -CN III palsy
• Dx:
  
  • Fisher SAH Scale (CT):
    
    • 1)No subarachnoid hemorrhage (SAH) or intraventricular hemorrhage (IVH) detected
    • 2)Diffuse, thin SAH, no clots
    • 3)Localized clots &/or layers of blood, no IVH
    • 4)SAH of any thickness with IVH or Intracranial Hemorrhage (ICH) present
  • Intracranial hemorrhage:
    
    • CT/MRI to look for AVMs or other vascular abnormalities
• Tx:
  
  • Subarachnoid hemorrhage has up to 45% mortality at 30days. Intracerebral hemorrhage has the highest mortality rate (difficult to tx)
  • Subarachnoid Hemorrhage:
    
    • -Control BP, consider nimodipine or nicardipine (Calcium channel blockers) to control vasospasm, elevated head of the bed, control pain & nausea (these increase intracranial pressure)
    • -Endovascular treatment: definitive, coil embolization, flow diversion
  • Surgery: clipping of aneurysms or AVMs, evac of clot
• Intracerebral Hemorrhage:
  
  • Supportive: reverse the anticoagulants if the pt is taking any, control BP

Question 6

Syncope

Answer 6

• Definition:
  
  • transient loss of consciousness/postural tone secondary to an acute decrease in cerebral blood flow. Characterized by a rapid recovery of consciousness without resuscitation
• Types:

Cardiac Syncope: arrhythmias (e.g. AV block, sick sinus syndrome), obstruction of blood flow (e.g. aortic stenosis, hypertrophic cardiomyopathy), massive MI

Vasovagal syncope: neurocardiogenic → most common cause of syncope

Orthostatic Hypotension: defect in vasomotor reflexes, common in elderly, diabetics, patients taking certain medications (e.g. diuretics, vasodilators)

Cerebral Vascular Disease: rare cause of syncope

Other noncardiogenic causes: metabolic causes (e.g. hypoglycemia, hyperventilation), hypovolemia (e.g. hemorrhage), hypersensitivity (syncope precipitated by wearing a tight collar or turning the head), mechanical reduction of venous return (e.g. Valsalva maneuver, post micturition), and various meds (e.g. Beta-blockers, nitrates, antiarrhythmics)

Question 7

Transient Ischemic Attack

Answer 7

• Definition:
  
  • transient episode of neurologic deficits caused by focal brain, spinal cord, or retinal ischemia without acute infarction
• Pathophys:
  
  • same mechanism as ischemic strokes
• S/sxs:
  
  • *New sudden onset of:
  • -Neurologic deficits lasting < 24 hours (resembles stroke pattern)
  • -Amaurosis Fugax: transient monocular vision loss
  • Pt can wrinkle the forehead
• Types of TIA:
  
  • 1.large artery low flow TIA (stenosis) likely carotid stenosis causing short-lived (minutes) decrease in flow to the brain. If the stenosis is > 70% tx surgically
  • 2.Embolic TIA: emboli often form in the heart (Afib)
  • Internal Carotid Artery: Amaurosis Fugax and weakness in the contralateral hand
  • ICA/MCA/ACA: cerebral hemisphere dysfunction. Sudden HA, speech changes, confusion
  • PCA: somatosensory defect
  • Vertebrobasilar: brainstem/cerebral symptoms (gait and proprioception)
• Scoring of TIAs:
  
  • ABCD2 Score: Predicts likelihood of stroke in next 2 days, 7 days, and 90 days.
  • -Age: > 60 = 1 point
  • -Blood pressure: >140/80: 1 point
  • -Clinical (neurologic deficits): 2 points if hemiparesis, 1 point if speech problems without weakness
  • -Duration: 2 points if 60+ min, 1 point if 10-59 minutes
  • -Diabetes: 1 point
  • **Admit all with a score of 5+; 2+ = Oral anticoags, 1 = OAC or aspiring, 0 = aspirin no antithrombotic therapy
• Dx:
  
  • -CT scan: to r/o hemorrhagic stroke
  • -MRI: more sensitive
  • Carotid doppler to look for stenosis
  • Cardiac Monitoring for Afib
  • Transthoracic Echocardiogram (TTE) is preferred initial test for most patients with a suspected cardiac or aortic source of emboli
  • Blood tests: CBC, CMP, Lipids, PT/PTT, ESR/CRP
• Tx:
  
  • Dual antiplatelet therapy (DAPT) using Aspirin (162 -325 loading dose, followed by 81 mg daily) plus clopidogrel (300 mg loading dose, followed by 75mg daily) for the first 21 days for patients with high-risk TIA ⇒ ABCD2 score 4+, and for patients with a minor ischemic stroke (NIHSS score = 5), then followed by long-term single agent antiplatelet therapy
  • -Aspirin monotherapy 162-325mg daily for low risk TIA, defined by an ABCD2 score < 4 → should continue on long term single agent platelet therapy
  • Afib anticoag with warfarin or direct oral anticoag (DOAC; if CHADS2 Score 2+ dabigatran (inhibit thrombin through reversible binding), apixaban, rivaroxaban, betrixaban(inhibit factor Xa)); once anticoag is started, antiplatelet should be stopped.