Management of Posterior Cerebral Artery (PCA) Stroke
Acute Reperfusion Therapy
For PCA stroke patients presenting within 4.5 hours, administer intravenous alteplase (0.9 mg/kg, maximum 90 mg) if no contraindications exist, as this improves functional outcomes even in isolated PCA occlusions. 1, 2, 3
Mechanical Thrombectomy Considerations
Mechanical thrombectomy for isolated PCA occlusions (P1 or P2 segments) remains controversial and is not routinely recommended based on current guidelines, which focus primarily on anterior circulation and basilar artery occlusions. 4
The 2024 guidelines for endovascular therapy specifically address basilar artery occlusion but do not provide Class I recommendations for isolated PCA territory strokes 4
For patients with P1 segment occlusions presenting within 6-24 hours with favorable perfusion imaging (large penumbra, small core), consider mechanical thrombectomy on a case-by-case basis, though this represents off-guideline use 5, 1
Combined aspiration and stent-retriever techniques achieve the highest first-pass reperfusion rates when thrombectomy is performed 5
Blood Pressure Management
Do not aggressively lower blood pressure in PCA stroke patients unless systolic BP exceeds 220 mmHg or diastolic exceeds 120 mmHg, as maintaining adequate perfusion pressure is critical to preserve the ischemic penumbra. 5, 1, 2
Before administering rtPA, blood pressure must be reduced to <185/110 mmHg 1, 2
Emergency antihypertensive treatment is indicated only if there is concomitant acute myocardial infarction, aortic dissection, acute renal failure, acute pulmonary edema, or preeclampsia/eclampsia 1, 2
Avoid rapid or excessive blood pressure reduction, which may exacerbate ischemia in the setting of arterial occlusion 5
Initial Evaluation and Stabilization
Perform immediate brain imaging (CT or MRI) to rule out hemorrhage and assess infarct extent, using NIHSS to quantify neurological deficit severity. 1, 2
Maintain airway, breathing, and circulation; intubate if airway is compromised or ventilation inadequate 1, 2
Provide supplemental oxygen to maintain saturation ≥94% 1, 2
Monitor and treat blood glucose to maintain levels <300 mg/dL (<16.63 mmol/L) 1
Correct hypotension and hypovolemia to maintain adequate systemic perfusion 2
Secondary Prevention and Medical Management
Initiate antiplatelet therapy immediately after excluding hemorrhage, using aspirin 81-325 mg daily as first-line therapy. 4
For patients with vertebrobasilar territory involvement and angiographic evidence of thrombus in the extracranial vertebral artery, anticoagulation for at least 3 months is recommended, whether or not thrombolytic therapy was used 4
The combination of aspirin plus extended-release dipyridamole (25 mg/200 mg twice daily) reduces recurrent vertebrobasilar stroke more effectively than aspirin alone (5.7% vs 10.8% recurrence) 4
Clopidogrel 75 mg daily is a reasonable alternative if aspirin is contraindicated 4
Ticlopidine 250 mg twice daily was superior to aspirin for secondary prevention in posterior circulation disease, though it is less commonly used due to side effects 4
Complication Management
Monitor closely for cerebral edema and increased intracranial pressure; do not use corticosteroids, but employ osmotic therapy and hyperventilation for patients who deteriorate. 1, 2
For large cerebellar infarcts causing brainstem compression and hydrocephalus, surgical decompression is recommended 1, 2
Treat new-onset seizures with short-acting medications (e.g., lorazepam IV) if not self-limiting 1
Treat sources of fever and use antipyretics for elevated temperatures 1
Rehabilitation
Begin initial assessment by rehabilitation professionals within 48 hours of admission, with therapy starting as soon as the patient is medically stable. 1, 2
Initiate frequent, brief out-of-bed activity involving active sitting, standing, and walking within 24 hours if no contraindications exist 1
Address cognitive impairments through interdisciplinary collaboration involving occupational therapists, speech therapists, and neuropsychologists 4
Prognostic Factors and Clinical Pearls
Age, baseline NIHSS score, infarct volume, and lack of IVT use independently predict poor functional outcome (mRS ≥2) in PCA stroke patients. 3
Complete recanalization at 24 hours is associated with better outcomes (aOR 0.37), while parenchymal hematoma occurrence worsens prognosis (aOR 2.37) 3
Poor outcome occurs in approximately 56% of medically treated PCA stroke patients, even with optimal management 3
Embolism from cardiac or undetermined sources accounts for up to half of PCA strokes, while local atherothrombotic disease is uncommon 6
Combined deep and superficial PCA territory infarcts involving the lateral thalamus are more frequent than commonly assumed and typically present with sensory deficits, slight motor deficits, and neuropsychological impairments 6, 7
Unilateral headache is a common presenting symptom, making complicated migraine an important differential diagnosis 6
Visual symptoms are typically described as negative phenomena (87%), and most patients (66%) can lateralize symptoms to a hemifield in both eyes 7
Concurrent numbness and tingling strongly suggest thalamic involvement 7
Critical Pitfalls to Avoid
Do not delay imaging in patients with isolated visual field defects and headache—20% of PCA strokes occur within 72 hours of a medical/surgical procedure or newly identified medical condition 7
Do not assume all visual field defects are ophthalmologic—consider urgent neuroimaging for unexplained visual phenomena, especially with concurrent neurological symptoms 8, 9
Every 30-minute delay in recanalization decreases the probability of good functional outcome by 8-14%—minimize door-to-treatment time 5, 1
Do not withhold IVT based solely on "mild" symptoms—NIHSS score independently predicts outcome, and IVT use improves functional outcomes in PCA stroke 3