What are the implications of a large volume acute left posterior cerebral artery (PCA) territory infarction?

From the Guidelines

A large volume acute left posterior cerebral artery (PCA) territory infarct requires immediate transfer to an intensive care or stroke unit for close monitoring and comprehensive treatment. This is based on the recommendations from the American Heart Association/American Stroke Association, which suggest that patients with large territorial strokes should be transferred to a higher level center if comprehensive care and timely neurosurgical intervention are not available locally 1.

Key Considerations

• The patient should undergo rapid assessment and stabilization, including airway management, blood pressure control, and neurological monitoring.
• Intravenous tissue plasminogen activator (tPA) should be considered if the patient presents within 4.5 hours of symptom onset and has no contraindications, as per the guidelines for early management of patients with acute ischemic stroke 1.
• For eligible patients presenting within 24 hours with large vessel occlusion, mechanical thrombectomy may be indicated.
• Antiplatelet therapy should be initiated, typically with aspirin 325 mg initially, followed by 81 mg daily.
• Blood pressure should be maintained below 180/105 mmHg for patients receiving thrombolysis, or below 220/120 mmHg for those not receiving thrombolysis.

Management of Cerebral Edema

• Patients with large territorial supratentorial infarctions are at high risk for complicating brain edema and increased intracranial pressure, and discussion of care options and possible outcomes should take place quickly with patients and caregivers 1.
• Measures to lessen the risk of edema and close monitoring of the patient for signs of neurological worsening during the first days after stroke are recommended.
• Early transfer of patients at risk for malignant brain edema to an institution with neurosurgical expertise should be considered.

Rehabilitation and Secondary Prevention

• Early rehabilitation including physical, occupational, and speech therapy should be initiated as soon as the patient is medically stable.
• Secondary prevention includes risk factor management with statins (e.g., atorvastatin 40-80 mg daily), blood pressure control, diabetes management, and lifestyle modifications.
• PCA territory infarcts often cause visual field defects (homonymous hemianopia), sensory deficits, and sometimes memory impairments due to involvement of the occipital lobe and potentially the thalamus or medial temporal structures, and these deficits should be addressed in the rehabilitation plan.

From the Research

Implications of a Large Volume Acute Left Posterior Cerebral Artery (PCA) Territory Infarction

• A large volume acute left posterior cerebral artery (PCA) territory infarction can have significant implications, including visual field deficits, sensory, motor, and neuropsychological deficits 2.
• The PCA syndrome includes more clinical signs than the well-known visual field deficits, and concomitant findings are frequently sensory, slight motor, and neuropsychological deficits 2.
• Unilateral headaches are a common presenting symptom, making complicated migraine an important differential diagnosis 2.
• Combined deep and superficial PCA territory infarcts involving the lateral thalamus are more frequent than commonly assumed and are mostly associated with sensory and reversible slight motor deficits 2.
• Occlusion of the precommunal PCA segment with associated paramedian midbrain infarction can cause severe motor deficits, oculomotor signs, and decreased consciousness, and has a poorer outcome than other PCA territory infarcts 2.

Clinical Presentations

• A large volume acute left PCA territory infarction can present with a range of clinical symptoms, including emotional lability, disorientation, complex visual hallucinations, and persecutory delusions 3.
• In some cases, the only acute manifestation of a stroke in the left hemisphere may be neuropsychiatric symptoms, such as acute psychosis 4.
• Visual abnormalities are present in the majority of patients with PCA territory infarcts, while motor weakness, cognitive and behavioral abnormalities, and ataxia are less common 5.

Outcome and Prognosis

• The outcome of a large volume acute left PCA territory infarction can vary depending on the underlying cause and the extent of the infarct 6.
• Features of the stroke that are associated with a significant increased risk of poor outcome include consciousness disturbances at stroke onset, mesencephalic and/or thalamic involvement, proximal large-artery disease, and basilar artery disease 6.
• The death rate and stroke recurrence rate can be significant, with a death rate of 7% and a stroke recurrence rate of 16% during the 6-month follow-up period 6.