What is the management of a patient presenting with a posterior circulation stroke?

Management of Posterior Circulation Stroke

For patients with acute basilar artery occlusion (BAO) who meet criteria from the BAOCHE or ATTENTION trials (NIHSS score ≥6, PC-ASPECTS ≥6, CTA with BAO, age 18-89 years), mechanical thrombectomy is strongly indicated within 12 hours of last known well and should be the primary treatment approach. 1

Initial Diagnostic Evaluation

• Imaging:

  • Non-contrast CT: Initial assessment to rule out hemorrhage and evaluate for posterior fossa edema/mass effect 2
  • CT/MR Angiography: Essential for identifying vertebral or basilar artery occlusion 2
  • DWI MRI: Most sensitive for early ischemic changes; pc-ASPECTS ≥8 associated with better outcomes 2
  • Note: Hyperdense basilar artery on non-contrast CT has 71% sensitivity and 98% specificity for basilar occlusion 1

• Clinical Assessment:

  • NIHSS has limitations for posterior circulation strokes - patients may present with low scores despite severe pathology 2
  • Key symptoms to recognize: Loss of consciousness, headache, nausea, vomiting, dizziness, double vision, vertigo, ataxia, nystagmus, visual field defects, and "locked-in syndrome" with proximal basilar occlusions 2

Acute Management Algorithm

1. Thrombolysis:

   • Administer alteplase (0.9 mg/kg, maximum 90 mg) within 4.5 hours of symptom onset 2
   • Recent evidence suggests alteplase may be beneficial 4.5-24 hours after onset in selected patients with posterior circulation stroke (89.6% vs. 72.6% functional independence at 90 days) 3

2. Mechanical Thrombectomy:

   • For basilar artery occlusion:
     • Within 12 hours of last known well: Class I recommendation 1
     • Between 12-24 hours from last known well: Class IIa recommendation 1
     • Beyond 24 hours: May be reasonable on case-by-case basis (Class IIb) 1
   • Technique options:
     • Suction Thrombectomy (ADAPT): Higher rates of complete reperfusion with shorter procedure duration 2
     • Stent Retriever Thrombectomy: Effective but with higher complication rates than ADAPT 2

3. Blood Pressure Management:

   • Maintain systolic BP 121-200 mmHg and diastolic 81-110 mmHg 2
   • Do not lower BP within first 24 hours unless exceeding 220/120 mmHg or other medical indications 2

4. Management of Complications:

   • Monitor for mass effect (25% of patients) and hydrocephalus (20% of patients) 2
   • Consider early decompressive suboccipital craniectomy for patients with mass effect 2
   • External ventricular drainage for obstructive hydrocephalus 2

Secondary Prevention

1. Antiplatelet Therapy:

   • Initiate aspirin (325 mg) within 24-48 hours after symptom onset (not within 24 hours if thrombolytic therapy administered) 2
   • Consider dual antiplatelet therapy with aspirin and clopidogrel for high-risk TIA or minor stroke 2
   • Long-term antiplatelet therapy for secondary prevention 2

2. Anticoagulation:

   • Recommended for at least 3 months for acute ischemic syndromes with angiographic evidence of thrombus in the extracranial vertebral artery 2

3. Management of Vascular Risk Factors:

   • Aggressive treatment of cerebrovascular risk factors with both drugs and lifestyle interventions 4

4. Vascular Intervention:

   • For basilar artery stenosis: Medical therapy preferred over stenting (high peri-procedural risk) 4
   • For vertebral stenosis: Intracranial stenosis best treated with medical therapy alone; extracranial stenosis may be considered for stenting in recurrent symptoms 4

Monitoring and Supportive Care

• Close monitoring of neurological signs and vital signs every 15-30 minutes during initial hours 2
• Assess swallowing function before oral feeding to prevent aspiration 2
• Consider nasogastric/nasoduodenal tube feeding if dysphagia is present 2
• Early mobilization to prevent complications 2
• Use subcutaneous anticoagulants or intermittent external compression stockings for immobilized patients 2
• Maintain blood glucose between 140-180 mg/dL 2

Special Considerations

• Posterior circulation strokes have historically higher mortality (40-86%) without treatment 2
• Successful reperfusion is a strong predictor of favorable outcome (odds ratio 4.57) 2
• Poor outcome predictors: Older age, higher NIHSS, lack of recanalization, atrial fibrillation, intracranial hemorrhage, and pc-ASPECTS ≤8 2
• Thrombectomy for posterior circulation distal or medium vessel occlusions (P1, P2, or more distal segments) remains unproven but may be reasonable in some circumstances 1