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

Initial Management of Posterior Circulation Stroke

Patients presenting with posterior circulation stroke should receive immediate clinical evaluation, urgent brain imaging (CT or MRI with vascular imaging), and consideration for reperfusion therapy within established time windows, with treatment decisions based on imaging findings and time of symptom onset. 1

Initial Assessment and Stabilization

• Rapid evaluation of airway, breathing, and circulation is essential, with particular attention to airway management in posterior circulation strokes which may affect consciousness 1
• Neurological examination focusing on:
  • Cranial nerve deficits (diplopia, dysarthria, dysphagia)
  • Coordination (ataxia, dysmetria)
  • Visual disturbances (hemianopia, cortical blindness)
  • Sensory symptoms (crossed sensory deficits)
  • Motor deficits (hemiparesis or quadriparesis)
  • Level of consciousness 2
• Vital signs monitoring with blood pressure checks every 15 minutes during initial assessment 1
• Blood glucose measurement to rule out hypoglycemia as a stroke mimic 1

Urgent Diagnostic Imaging

• Non-contrast CT brain should be performed immediately to exclude hemorrhage 1, 2
• CT angiography (CTA) from aortic arch to vertex should be performed at the time of initial brain CT to assess both extracranial and intracranial circulation 1
• MRI with diffusion-weighted imaging is particularly valuable for posterior circulation strokes, as CT may miss early ischemic changes in the posterior fossa due to beam hardening artifacts 1
• A hyperdense basilar artery on non-contrast CT is highly specific (98%) for basilar artery occlusion and predicts poor outcomes 1

Laboratory Investigations

• Complete blood count, electrolytes, coagulation studies (aPTT, INR), renal function, and capillary glucose should be obtained routinely 1
• Electrocardiogram (ECG) to assess baseline cardiac rhythm and evidence of structural heart disease 1

Reperfusion Therapy Considerations

1. Intravenous thrombolysis (alteplase):

   • Should be administered within 4.5 hours of symptom onset in eligible patients 1, 2
   • Posterior circulation strokes have similar benefits and lower hemorrhage risks compared to anterior circulation strokes 1, 3
   • Dose: 0.9 mg/kg (maximum 90 mg) with 10% given as initial bolus over 1 minute, followed by remainder over 60 minutes 2

2. Endovascular thrombectomy:

   • Consider for basilar artery occlusion based on recent evidence from ATTENTION and BAOCHE trials 3
   • Particularly important for patients with basilar artery occlusion, which has high mortality rates (45-86%) without treatment 1
   • Can be considered beyond the standard time window for thrombolysis in selected cases 1

Blood Pressure Management

• For patients eligible for reperfusion therapy with BP >185/110 mmHg, administer labetalol or nicardipine to lower blood pressure 2
• For patients not eligible for thrombolysis, only treat blood pressure if systolic >220 mmHg or diastolic >120 mmHg 1
• Avoid aggressive blood pressure reduction which may worsen ischemia 1

Special Considerations for Posterior Circulation Stroke

• Recognition challenges: Posterior circulation strokes are often misdiagnosed initially due to nonspecific symptoms like dizziness, nausea, and vomiting 4
• Door-to-needle time: Studies show longer door-to-needle times for posterior circulation strokes compared to anterior circulation strokes 4
• Basilar artery occlusion: Requires urgent treatment due to high mortality rate; consider extended time window for reperfusion therapy 1
• Space-occupying cerebellar strokes: May require decompressive craniectomy to prevent brainstem compression 3

Monitoring After Initial Management

• Frequent neurological assessments: Every 15 minutes during and after IV rtPA infusion for 2 hours, every 30 minutes for 6 hours, then hourly until 24 hours after treatment 2
• Blood pressure monitoring: Every 15 minutes during the first 2 hours, then as clinically indicated 2
• Monitor for complications: Particularly for posterior fossa edema which can lead to rapid deterioration 2

Common Pitfalls to Avoid

• Misdiagnosis due to nonspecific symptoms like dizziness, nausea, and vomiting 4
• Delayed recognition of posterior circulation strokes due to atypical presentations 4
• Overlooking basilar artery occlusion, which has high mortality without treatment 1
• Relying solely on CT which may miss early posterior fossa infarcts; consider MRI when available 1
• Failure to monitor for deterioration from brainstem compression due to cerebellar edema 3

By following this structured approach to the initial management of posterior circulation stroke, clinicians can optimize outcomes for these challenging cases that represent approximately 20% of all ischemic strokes 5.