What is the management for a patient with an acute infarct involving the posterior cerebral artery (PCA)?

Management of Acute Posterior Cerebral Artery (PCA) Infarct

Patients with acute PCA infarcts should be admitted to a specialized stroke unit or neurocritical care unit for close monitoring and comprehensive treatment to optimize outcomes and minimize complications. 1

Initial Assessment and Management

• Immediate neuroimaging with non-contrast CT or MRI is essential to confirm diagnosis, assess infarct size, and guide treatment decisions 2
• Early identification of patients at risk for cerebral edema is critical, with frank hypodensity on CT within 6 hours, involvement of ≥1/3 of the MCA territory, or early midline shift being predictive factors 1
• MRI diffusion-weighted imaging (DWI) within 6 hours is useful, with volumes ≥80 mL predicting a rapid fulminant course 1
• Transfer to a higher level center should be considered if comprehensive care and timely neurosurgical intervention are not available locally 1

Acute Reperfusion Therapy

• Intravenous thrombolysis (IV rtPA) should be administered if the patient presents within 4.5 hours of symptom onset and has no contraindications 2
• For large vessel occlusions in the posterior circulation, endovascular therapy with stent retrievers has shown benefit in recent trials (ATTENTION and BAOCHE) for basilar artery occlusions 3
• Mechanical thrombectomy may be considered for P2 or P3 segment occlusions of the PCA, particularly in patients with higher NIHSS scores (≥10) or those ineligible for IV thrombolysis 4

Management of Cerebral Edema

• Cerebral edema typically peaks 3-4 days after injury but can accelerate within 24 hours with early reperfusion of necrotic tissue 1

• Medical management to minimize edema development includes:

  • Restriction of free water to avoid hypo-osmolar fluid 1
  • Avoidance of excess glucose administration 1
  • Minimization of hypoxemia and hypercarbia 1
  • Treatment of hyperthermia 1
  • Avoidance of antihypertensive agents that induce cerebral vasodilation 1
  • Elevation of the head of bed at 20° to 30° to assist venous drainage 1

• For increased intracranial pressure (ICP), standard management includes:

  • Hyperventilation (target mild hypocapnia with PCO2 30-35 mm Hg) 1
  • Hypertonic saline 1
  • Osmotic diuretics (mannitol 0.25-0.5 g/kg IV over 20 minutes every 6 hours, with maximal dose of 2 g/kg) 1
  • Intraventricular drainage of cerebrospinal fluid 1
  • Decompressive surgery 1

Surgical Interventions

• Decompressive craniectomy should be considered for space-occupying cerebellar infarcts 3
• For PCA infarcts with severe edema, surgical decompression may be necessary if medical management fails 1
• Emergent carotid endarterectomy (CEA) is generally not performed in acute ischemic stroke settings, especially with large deficits, due to high risk of adverse events 1

Post-Acute Care

• Admission to a specialized stroke unit reduces mortality and morbidity after stroke 1
• Continuation of statin therapy during the acute period is reasonable for patients already taking statins 1
• Administration of aspirin is recommended within 24-48 hours after stroke onset (delayed for 24 hours in patients who received thrombolytic therapy) 2
• Early rehabilitation assessment should be initiated to optimize functional recovery 2

Prognosis and Complications

• Approximately 25% of patients experience neurological deterioration during the first 24-48 hours after stroke 1
• Despite intensive medical management, mortality rates in patients with increased ICP remain as high as 50-70% 1
• Hemorrhagic transformation is a potential complication, occurring more frequently in cardioembolic strokes 5
• Poor outcome is associated with:
  • Consciousness disturbances at stroke onset 6
  • Mesencephalic and/or thalamic involvement 6
  • Proximal large-artery disease 6
  • Basilar artery disease 6

Special Considerations for PCA Infarcts

• Visual field defects are the most common clinical manifestation of PCA territory infarcts 6
• Memory impairment occurs frequently, especially with dominant hemisphere involvement 7
• Sensory deficits occur in approximately one-third of cases 7
• Embolism from cardiac and vascular sources is the predominant cause of PCA infarction 5

Common Pitfalls and Caveats

• Delay in treatment initiation significantly worsens outcomes - establish rapid transfer protocols to endovascular-capable centers 2
• Waiting to assess clinical response to IV rtPA before pursuing endovascular therapy is not recommended and may lead to worse outcomes 2
• Patients with PCA infarcts may have subtle or atypical presentations, including visual complaints that predominate over motor symptoms 7
• Careful monitoring for neurological deterioration is essential, as approximately 25% of patients deteriorate within the first 48 hours 1