What is the immediate management of an acute cerebellar infarction caused by vertebral artery dissection?

Management of Cerebellar Infarct with Vertebral Artery Dissection

For acute cerebellar infarction caused by vertebral artery dissection, initiate immediate anticoagulation with intravenous heparin (targeting PTT 1.5-2.0 times control) or low molecular weight heparin, followed by warfarin (target INR 2.0-3.0) for 3-6 months, then transition to antiplatelet therapy; simultaneously arrange urgent neurosurgical consultation and intensive care monitoring for signs of cerebellar edema requiring decompressive suboccipital craniectomy. 1, 2

Immediate Diagnostic Confirmation

• Obtain contrast-enhanced CTA or MRA urgently to confirm vertebral artery dissection, as these modalities have largely supplanted catheter angiography for diagnosis. 1
• Brain MRI is superior to CT for detecting acute cerebellar infarction, particularly in the first 24-48 hours when CT may appear normal. 3
• Carotid duplex ultrasonography may miss dissections beginning above the angle of the mandible; contrast-enhanced CTA and MRA are superior in these cases. 1

Critical Triage and Monitoring

Transfer immediately to intensive care or stroke unit with neurosurgical consultation, even if the patient appears stable initially, as deterioration can occur rapidly. 2, 4

Neurological Monitoring Parameters

• Monitor frequently for signs of cerebellar swelling and brainstem compression: declining level of consciousness, pupillary changes, loss of oculocephalic responses, and new brainstem signs. 2
• Obtain serial CT scans in the first 48 hours to identify patients developing symptomatic swelling before clinical deterioration becomes irreversible. 2
• Drowsiness or declining consciousness in bilateral cerebellar infarcts represents a neurosurgical emergency requiring immediate intervention. 4

Antithrombotic Therapy (Primary Treatment)

Anticoagulation is the cornerstone of treatment for symptomatic vertebral artery dissection (Class IIa recommendation). 1, 5

Anticoagulation Regimen Options

• Intravenous heparin: Dose-adjusted to prolong PTT to 1.5-2.0 times control, followed by warfarin (target INR 2.5, range 2.0-3.0) for 3-6 months. 1
• Low molecular weight heparin: Use dosing recommended for venous thromboembolism, followed by warfarin (target INR 2.5, range 2.0-3.0) for 3-6 months. 1
• Direct oral anticoagulation: May be initiated without antecedent heparin in select cases. 1

Transition to Antiplatelet Therapy

• After 3-6 months of anticoagulation, transition to aspirin (81-325 mg daily) or clopidogrel (75 mg daily) for long-term secondary prevention. 1, 5
• The prognosis is usually favorable with appropriate antithrombotic therapy. 1, 5

Critical Anticoagulation Caveat

Do not anticoagulate if there is concern for intracranial extension of dissection with subarachnoid hemorrhage risk, as anticoagulation may adversely influence outcomes in this scenario. 1, 5

Medical Management of Cerebellar Edema

Supportive Care Measures

• Elevate head of bed 0-30 degrees to help control intracranial pressure. 2
• Maintain isotonic fluid resuscitation only—avoid hypotonic fluids and dextrose-containing solutions to ensure adequate cerebral perfusion. 2, 4
• Maintain normoglycemia and treat hyperthermia aggressively. 2
• Provide supplemental oxygen for at least 24 hours. 2

Osmotic Therapy

• Administer mannitol or hypertonic saline for patients with clinical deterioration from cerebral edema (Class IIa recommendation). 2
• Monitor serum osmolality at regular intervals with target of 300-310 mOsmol/kg when using osmotic therapy. 2

Blood Pressure Management

• Maintain systolic BP <220 mmHg and diastolic <120 mmHg in the acute setting to preserve cerebral perfusion while avoiding hemorrhagic transformation. 4
• Avoid aggressive blood pressure lowering, as hypertension may be compensatory to maintain cerebral perfusion pressure in the setting of brainstem compression. 4
• Maintain cerebral perfusion pressure >60 mmHg using volume replacement and/or catecholamines if necessary. 2

Medications to Avoid

Do not use corticosteroids, barbiturates, or hypothermia for cerebellar edema—there is insufficient evidence and they are not recommended (Class III recommendation). 2

Surgical Intervention

Indications for Suboccipital Craniectomy

Perform suboccipital craniectomy with dural expansion in patients with cerebellar infarctions who deteriorate neurologically despite maximal medical therapy (Class I recommendation, Level of Evidence B). 2

Specific Surgical Triggers

• Declining level of consciousness (drowsiness progressing to stupor). 2, 4
• Radiographic signs of mass effect: fourth ventricular compression, hydrocephalus, or brainstem compression. 2, 6
• Clinical signs of brainstem compression: pupillary changes, loss of brainstem reflexes, respiratory irregularities. 2

Critical Surgical Pitfall

Do not perform ventriculostomy alone without decompressive craniectomy, as this can cause fatal upward herniation through the tentorial notch. 2, 4

• While some patients with hydrocephalus and preserved consciousness may initially respond to external ventricular drainage alone, those with declining consciousness require definitive decompression. 6
• Reserve external ventricular drainage for patients with worsening consciousness and radiologically evident ventricular enlargement who have not yet developed signs of direct brainstem compression. 6

Endovascular Intervention for Dissection

Carotid angioplasty and stenting might be considered when ischemic neurological symptoms persist or recur despite antithrombotic therapy (Class IIb recommendation). 1

• Surgical revascularization techniques include direct repair and resection with vein graft replacement, but are rarely needed. 1
• Endovascular stent angioplasty has been successful in small case series but carries complication risks. 1
• One case report describes successful embolization of the affected vertebral artery to prevent further distal embolism when anticoagulation failed. 7

Long-Term Medical Management

Statin Therapy

Initiate high-intensity statin therapy to reduce LDL cholesterol to <70 mg/dL (Class I recommendation for extracranial vertebral artery disease; Class IIa for post-stroke patients). 5

• Statins provide benefits beyond cholesterol reduction: endothelial stabilization, increased nitric oxide bioavailability, reduced oxidative stress, and decreased vascular inflammation. 5
• For patients intolerant to statins, use bile acid sequestrants and/or niacin (Class IIa recommendation). 5

Blood Pressure Control

• The safety and effectiveness of specific antihypertensive agents (β-blockers, ACE inhibitors, non-dihydropyridine calcium channel blockers) to reduce arterial wall stress are not well established (Class IIb recommendation). 1
• However, long-term blood pressure control to normal range is reasonable to prevent recurrence. 1

Lifestyle Modifications

• Smoking cessation (Class I recommendation). 5
• Diet and exercise modifications, particularly for patients with diabetes mellitus. 5

Follow-Up Imaging

Serial non-invasive imaging of the extracranial vertebral arteries is reasonable to assess disease progression and exclude development of new lesions (Class IIa recommendation). 5

Common Pitfalls to Avoid

• Delaying neurosurgical consultation is the most critical error—involve neurosurgery early even if the patient appears stable, as deterioration can be rapid and irreversible. 2, 4
• Relying on initial CT scan alone—normal CT does not exclude cerebellar infarction; obtain MRI if clinical suspicion is high. 3
• Using hypoosmolar fluids—maintain isotonic or mildly hypertonic solutions only. 2, 4
• Minimizing sedation excessively—avoid medications that impair consciousness assessment to allow accurate neurological monitoring. 2
• Performing ventriculostomy without craniectomy in patients with declining consciousness—this risks upward herniation. 2, 4
• Ignoring cardiac monitoring—arrhythmias are common after cerebellar infarcts compressing the brainstem. 2

DVT Prophylaxis

Initiate DVT prophylaxis with subcutaneous low-dose heparin or low molecular weight heparin once it is safe to do so, typically after consulting neurosurgery if surgical intervention has occurred. 2