What is the recommended treatment for central nervous system vasculitis?

Treatment of Central Nervous System Vasculitis

For CNS vasculitis, immediate induction therapy with high-dose glucocorticoids combined with cyclophosphamide is the standard of care, followed by maintenance immunosuppression for at least 24 months to prevent relapse and optimize functional outcomes.

Immediate Induction Therapy

Glucocorticoid Regimen

• Start with intravenous methylprednisolone 500-1000 mg daily for 3-5 days, then transition to oral prednisolone 1 mg/kg/day (maximum 60-80 mg/day) 1, 2
• Maintain high-dose glucocorticoids for at least 1 month before any tapering 3
• Do not reduce below 15 mg/day during the first 3 months 3
• Taper gradually to a maintenance dose of 5-7.5 mg/day by 6 months 3

Immunosuppressive Agent Selection

Cyclophosphamide is the preferred first-line agent for CNS vasculitis based on Level 1A evidence for life-threatening vasculitic disease 1, 4, 5:

• Oral dosing: 2 mg/kg/day (maximum 200 mg/day) for 3-6 months 1, 2
• Intravenous pulses: 0.6 g/m² monthly or 15 mg/kg at weeks 0,2,4,7,10,13 3, 1
• Reduce dose by 25% in patients over 60 years and by 50% in those over 70 years 3

Rituximab is an evidence-based alternative (Level 1B) 1:

• Dose: 375 mg/m² intravenously weekly for 4 weeks 3, 1
• Particularly appropriate for younger patients with fertility concerns 3
• Consider as first-line if cyclophosphamide is contraindicated 1

Critical Supportive Measures

Mandatory Prophylaxis

• Pneumocystis jirovecii prophylaxis: Trimethoprim-sulfamethoxazole 800/160 mg on alternate days (or 400/80 mg daily) for all patients receiving cyclophosphamide or high-dose steroids 3, 1
• MESNA administration: Co-administer with cyclophosphamide to prevent hemorrhagic cystitis, with aggressive hydration on infusion days 3, 1
• Bone protection: Calcium, vitamin D, and bisphosphonate therapy for glucocorticoid-induced osteoporosis 3

Monitoring Requirements

• Do not use ANCA titers to guide treatment changes; base decisions on structured clinical neurological assessment and MRI findings 1
• Monitor complete blood counts weekly during initial cyclophosphamide therapy, then every 2 weeks 3
• Perform structured neurological examination at every visit 3
• Investigate any persistent unexplained hematuria due to bladder cancer risk with cyclophosphamide 6, 3

Maintenance Therapy: Essential for Long-Term Success

Maintenance immunosuppression is critical and strongly associated with better outcomes. A French cohort study demonstrated that maintenance therapy was independently associated with prolonged remission (OR 4.32, P=0.002) and better functional status (OR 8.09, P<0.0001) compared to induction therapy alone 7.

Maintenance Options (in order of evidence strength)

After achieving remission (typically 3-6 months), transition to maintenance therapy:

1. Azathioprine (first-line with strongest evidence) 3, 8:

   • Dose: 1.5-2 mg/kg/day for 18-24 months 3
   • Continue for at least 24 months after sustained remission 1

2. Mycophenolate mofetil (alternative) 3, 1, 8:

   • Dose: 2000 mg/day in divided doses 3
   • Has achieved complete neurological recovery in documented CNS vasculitis cases 1

3. Methotrexate (alternative) 3, 8:

   • Dose: 20-25 mg weekly 3
   • Contraindicated if GFR <60 mL/min/1.73 m² 3

4. Rituximab (for relapsing disease) 3:

   • Dose: 500 mg IV every 6 months or 1000 mg IV every 4 months 3

Glucocorticoid Maintenance

• Continue prednisolone 5-7.5 mg/day for at least 18-24 months 3, 1
• After 2 years, taper by 1 mg every 2 months 3

Duration of Treatment

Minimum maintenance therapy duration is 24 months 1, 7:

• Extending therapy to 4 years after diagnosis further reduces relapse risk 3
• The French cohort showed 66% achieved prolonged remission with appropriate maintenance therapy 7
• Overall mortality was 8%, with 56% achieving good functional status (modified Rankin Scale ≤2) at long-term follow-up 7

Management of Refractory Disease

If no clinical response after 4 weeks of cyclophosphamide:

• Switch to rituximab (or vice versa if rituximab was used initially) 1, 5
• Refer to an expert vasculitis center for further evaluation and potential enrollment in clinical trials 6, 1
• Consider alternative agents such as mycophenolate mofetil or biological agents, though evidence is limited 6, 8

Critical Pitfalls to Avoid

• Never delay treatment while waiting for biopsy results in rapidly deteriorating patients with compatible clinical features and positive serology 3
• Never use alternate-day glucocorticoid regimens, which increase relapse risk 3
• Never omit Pneumocystis prophylaxis in patients receiving cyclophosphamide or high-dose steroids 3, 1
• Never prescribe methotrexate when GFR <60 mL/min/1.73 m² 3
• Never stop maintenance therapy prematurely; inadequate duration is associated with worse functional outcomes 7
• Never use induction therapy alone without maintenance; this approach results in significantly higher relapse rates and poorer functional status 7

Multidisciplinary Management

• Manage patients at centers experienced in CNS vasculitis care with access to neurology, rheumatology, and neuroradiology expertise 3, 1
• Ensure availability of rapid MRI, cerebral angiography, and neurosurgical biopsy capabilities 4
• Coordinate care with specialists for management of treatment-related complications 3