Management of Posterior Circulation Stroke

Clinical Presentation and Recognition

Posterior circulation strokes account for approximately 20% of all ischemic strokes but can be challenging to diagnose due to non-specific symptoms 1, 2
Common symptoms include loss of consciousness, headache, nausea, vomiting, dizziness, double vision, hearing loss, slurred speech, vertigo, imbalance, and unilateral extremity weakness 2, 3
Physical examination may reveal ataxia, nystagmus, and visual field defects 3, 4
The National Institutes of Health Stroke Scale (NIHSS) may underestimate severity in posterior circulation strokes as it focuses more on limb and speech impairments rather than cranial nerve lesions 3

Non-contrast CT is used to exclude hemorrhage, but has limitations in the posterior fossa due to beam hardening artifacts 3
MRI is preferred for diagnosing posterior fossa lesions, with diffusion-weighted imaging being particularly sensitive 3
CT angiography or MR angiography should be performed to identify large vessel occlusions 1, 5
Posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) ≥8 is associated with better outcomes 3, 6

Intravenous alteplase (0.9 mg/kg, maximum 90 mg, with 10% given as bolus and remainder over 60 minutes) is recommended within 4.5 hours of symptom onset 7, 8
Intravenous thrombolysis appears appropriate as first-line therapy for posterior circulation stroke 7
In patients with basilar artery occlusion, expert consensus suggests using IVT up to 24 hours unless contraindicated 5
For basilar artery occlusion, EVT plus best medical treatment is suggested over best medical treatment alone, particularly in patients with NIHSS ≥10 5
Mechanical thrombectomy using stent retrievers or large bore distal aspiration catheters has shown high recanalization rates (up to 92%) 6
Successful recanalization is a strong predictor of survival in basilar artery occlusion 6
Failure of recanalization is associated with high mortality 6

Maintain systolic blood pressure between 121-200 mmHg and diastolic pressure between 81-110 mmHg in the first 24 hours unless it exceeds 220/120 mmHg 6
Maintain blood glucose between 140-180 mg/dL 6
Consider decompressive hemicraniectomy for malignant middle cerebral artery stroke, particularly in patients under 60 years 8
In dysphagic patients, ASA (80 mg daily) and clopidogrel (75 mg daily) may be given by enteral tube or ASA by rectal suppository (325 mg daily) 8

For high-risk TIA or minor stroke, dual antiplatelet therapy with aspirin and clopidogrel is recommended for 21-90 days, followed by single antiplatelet therapy 8
For patients with very high risk of recurrent stroke (symptom onset within 48 hours), aggressive antithrombotic therapy should be initiated 8
GI protection may be considered in patients on dual antiplatelet therapy who are at higher risk of GI bleeding 8

Medical management for vertebral artery disease should follow guidelines for carotid artery disease 9
For patients with acute ischemic syndromes involving vertebral artery territory with angiographic evidence of thrombus, anticoagulation is generally recommended for at least 3 months 9

Predictors of poor outcome include older age, higher NIHSS score, lack of recanalization, atrial fibrillation, intracranial hemorrhage, and pc-ASPECTS ≤8 3

Regular follow-up imaging may be necessary to monitor for restenosis, particularly in patients who have undergone interventional procedures 9
Restenosis generally does not require revascularization unless it leads to recurrent ischemic symptoms or progresses to preocclusive severity 9