What is the management of subacute posterior circulation stroke?

Management of Subacute Posterior Circulation Stroke

Mechanical thrombectomy is recommended for patients with basilar artery occlusion in the subacute phase, with evidence showing improved functional outcomes and reduced mortality compared to medical therapy alone. 1

Initial Assessment and Diagnosis

• Clinical Presentation: Posterior circulation strokes present with distinctive symptoms:

  • Loss of consciousness, headache, nausea, vomiting, dizziness
  • Double vision, hearing loss, slurred speech, vertigo
  • Ataxia, nystagmus, visual field defects
  • "Locked-in syndrome" with proximal basilar occlusions 1

• Diagnostic Imaging:

  • Non-contrast CT scan to rule out hemorrhage
  • CT or MR angiography to identify vertebral or basilar artery occlusion
  • MRI is preferred for posterior fossa lesions due to better visualization 2, 3
  • Posterior circulation ASPECTS (pc-ASPECTS) score ≥8 is associated with better outcomes 1

Acute Management (First 24-48 Hours)

1. Revascularization Strategies:

   • Mechanical thrombectomy for basilar artery occlusion, with newer devices (Solitaire stent retriever, ACE reperfusion catheters) showing higher recanalization rates (92%) 1
   • Consider extended time windows for basilar artery thrombosis compared to anterior circulation strokes 2

2. Antithrombotic Therapy:

   • For acute ischemic syndromes with angiographic evidence of thrombus in the extracranial vertebral artery, anticoagulation is recommended for at least 3 months 1
   • Initiate aspirin (325 mg) within 24-48 hours after symptom onset, but not within 24 hours if thrombolytic therapy was administered 2
   • For high-risk patients, dual antiplatelet therapy with aspirin and clopidogrel may be considered 2, 4

3. Blood Pressure Management:

   • Maintain systolic blood pressure between 121-200 mmHg and diastolic pressure between 81-110 mmHg 1
   • Do not lower blood pressure within first 24 hours unless it exceeds 220/120 mmHg or there are other medical indications 1

4. Management of Cerebral Edema:

   • Monitor for signs of increased intracranial pressure, particularly in large cerebellar infarctions
   • Consider decompressive suboccipital craniectomy for cerebellar infarction with mass effect 2
   • External ventricular drainage may be necessary for obstructive hydrocephalus 2

Subacute Management

1. Nutritional Support:

   • Assess swallowing function before initiating oral feeding to prevent aspiration 1
   • Patients with brain stem infarctions, multiple strokes, large hemispheric lesions, or depressed consciousness are at highest risk for aspiration 1
   • Consider nasogastric or nasoduodenal tube feeding if dysphagia is present 1

2. Prevention of Complications:

   • Early mobilization to prevent deep vein thrombosis, pressure sores, and orthopedic complications 1
   • Use subcutaneous anticoagulants or intermittent external compression stockings for immobilized patients 1
   • Monitor for and promptly treat infections, particularly pneumonia and urinary tract infections 1
   • Monitor blood glucose levels and maintain between 140-180 mg/dL 1

3. Medical Management:

   • For patients with atherosclerosis of the extracranial vertebral arteries in whom aspirin is contraindicated, clopidogrel (75 mg daily) or ticlopidine (250 mg twice daily) are reasonable alternatives 1
   • Medical treatment has been shown to be superior to stenting for basilar artery stenosis 2, 5

Secondary Prevention

1. Antiplatelet Therapy:

   • Long-term antiplatelet therapy is indicated for secondary prevention 2
   • In ESPS-2 trial, combination of aspirin plus dipyridamole reduced vertebrobasilar territory stroke or TIA to 5.7% compared with 10.8% with placebo 1

2. Management of Vertebral Artery Disease:

   • Medical management should follow guidelines for carotid artery disease 1
   • Surgical options for vertebral artery stenosis include endarterectomy and vessel reconstruction, with early complication rates of 2.5-25% and perioperative mortality rates of 0-4% 1
   • Endovascular treatment may be considered for symptomatic vertebral artery stenosis, particularly for recurrent symptoms despite medical therapy 5

3. Risk Factor Management:

   • Aggressive control of vascular risk factors (hypertension, diabetes, hyperlipidemia, smoking cessation) 2
   • High-intensity statin therapy is recommended 4

Special Considerations

• Monitoring: Close monitoring of neurological signs and vital signs is essential, with assessments every 15-30 minutes during the initial hours 2

• Pitfalls to Avoid:

  • Relying solely on NIHSS for posterior circulation stroke assessment, as it emphasizes limb and speech impairments over cranial nerve lesions 1
  • Delaying diagnosis due to non-specific symptoms that can mimic other conditions 1
  • Overlooking basilar artery occlusion, which can have an extended prodrome lasting days to months 1

• Follow-up Imaging: For patients who have undergone vertebral artery revascularization, serial noninvasive imaging of the extracranial vertebral arteries is reasonable at intervals similar to those for carotid revascularization 1

The management of posterior circulation stroke requires specialized attention due to its unique presentation and high mortality rate. Early recognition, appropriate imaging, and prompt intervention are crucial for improving outcomes in these patients.