Background Wegener's granulomatosis (WG) is a systemic necrotising granulomatous vasculitis that primarily affects the respiratory tract and kidneys and has a strong association with Proteinase3-Antineutrophil Cytoplasmic Antibodies (ANCA). Both central nervous system involvement (about 10% of cases) and positive perinuclear-ANCA (p-ANCA, about 5% of cases), are relatively unusual in this disease.

Case report A 57-year-old farmer presented with otalgia, deafness, constitutional symptoms and persistent left-sided headache, followed some months later by unilateral facial nerve palsy. Treatment of the facial palsy with corticosteroids resulted in prompt resolution of headache but subsequent prednisolone dependence. Inflammatory markers and p-ANCA were persistently positive although Myeloperoxidase/Proteinase3 serology was negative. Extensive infection and inflammation screen tests were normal as was a temporal artery biopsy. Empirical Cyclophosphamide was given for possible vasculitis with improvement in inflammatory markers but not symptoms. Sequential cranial MRI with contrast showed diffuse meningeal enhancement. Meningeal biopsy revealed a necrotising granulomatous inflammation suggestive of WG with no evidence of infection. There was no evidence of systemic involvement. The patient responded to Methotrexate alongside a tapering dose of prednisolone.

Conclusion In patients with atypical steroid-responsive headache and cranial nerve involvement, the possibility of CNS vasculitis, in particular limited WG should be considered.