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

Initial Management of Posterior Circulation Stroke

The initial management of a patient with posterior circulation stroke requires immediate brain imaging (CT or MRI) within 24 hours of symptom onset, along with non-invasive vascular imaging from aortic arch to vertex, and prompt evaluation for thrombolytic therapy if within the treatment window. 1, 2

Immediate Assessment and Stabilization

• Airway, Breathing, Circulation: Posterior circulation strokes may require more aggressive airway management than anterior circulation strokes, especially if the patient has altered consciousness 1
• Vital Signs: Monitor every 30 minutes while in ED; more frequently (every 15 minutes) during thrombolytic infusion 1
• Blood Glucose: Perform immediate fingerstick glucose test to rule out hypoglycemia (a common stroke mimic) 1
• Neurological Assessment: Complete standardized stroke scale assessment (NIHSS) 2

Diagnostic Imaging

1. Brain Imaging:

   • Immediate non-contrast CT or MRI brain scan 1
   • MRI with diffusion-weighted imaging is particularly valuable for posterior circulation strokes as CT may miss early ischemic changes in the posterior fossa 1, 3
   • Target door-to-CT completion time: 25 minutes 1

2. Vascular Imaging:

   • CT angiography (CTA) or MR angiography (MRA) from aortic arch to vertex 1
   • CTA is recommended at the time of brain CT to visualize intracranial circulation, posterior circulation, and aortic arch 1

Laboratory Investigations

• Complete blood count
• Electrolytes
• Coagulation studies (aPTT, INR)
• Renal function (creatinine, eGFR)
• Electrocardiogram (ECG) 1, 2

Time-Sensitive Interventions

Thrombolytic Therapy

• Intravenous alteplase (0.9 mg/kg, maximum 90 mg) with 10% as bolus and 90% as infusion over 60 minutes 2
• Target door-to-needle time: <60 minutes 1, 2
• Evidence suggests thrombolysis for posterior circulation strokes has similar benefits with potentially lower hemorrhage risks compared to anterior circulation strokes 1, 4
• Note: Posterior circulation strokes are often misdiagnosed or recognized later than anterior circulation strokes, leading to longer door-to-needle times 5

Special Considerations for Posterior Circulation

• Basilar artery occlusion may have a longer time window for revascularization therapy compared to other stroke types 1, 6
• Patients with posterior circulation symptoms (dizziness, nausea, vomiting, ataxia) without motor weakness or speech disturbance should still be considered for urgent evaluation 1, 5
• Recent evidence from the ATTENTION and BAOCHE trials demonstrates benefit of thrombectomy for basilar artery occlusion 6

Management of Complications

• Cerebellar Edema: Monitor closely for signs of brainstem compression; surgical decompression may be necessary for space-occupying cerebellar strokes 2, 6
• Blood Pressure Management: Maintain permissive hypertension initially to support cerebral perfusion 2
• DVT Prophylaxis: Use subcutaneous anticoagulants, intermittent compression devices, or aspirin for immobilized patients 2

Common Pitfalls to Avoid

1. Delayed Recognition: Posterior circulation symptoms (dizziness, nausea, vomiting) may be mistaken for benign conditions, delaying diagnosis 5
2. Inadequate Imaging: CT alone may miss posterior fossa infarcts; consider MRI when posterior circulation stroke is suspected 1, 3
3. Failure to Monitor for Brainstem Compression: Cerebellar infarcts can lead to life-threatening edema requiring urgent surgical intervention 2, 6
4. Overlooking Basilar Artery Occlusion: This condition has high mortality without prompt treatment 6, 3

Early Secondary Prevention

• Initiate aspirin (325 mg initially, then 81-325 mg daily) within 24-48 hours if no contraindications and thrombolysis not administered 2
• Begin early rehabilitation within 24-48 hours if patient is stable 2

Posterior circulation strokes account for approximately 20% of all ischemic strokes 7 but present unique diagnostic and management challenges due to their variable presentation and the critical structures involved. Prompt recognition, imaging, and treatment are essential to improve outcomes in these patients.