P-ANCA cranial pachymeningitis: a case report.

Pachymeningitis is an inflammatory process that thickens the dura mater. This disease has various etiologies including infectious, neoplastic, or autoimmune diseases. We present the case of a patient who developed cranial pachymeningitis with a clinical and biological picture suggestive of a neurological form of vasculitis. A 51-year-old woman developed rhinitis, otitis media, headaches, and deterioration of her condition after a course of recombinant hepatitis B vaccine. After a booster dose of the vaccine, she developed unilateral visual loss and impairment of multiple cranial nerves. Blood analysis showed inflammation and presence of antimyeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA). Cranial magnetic resonance imaging (MRI) showed pachymeningitis. A complete remission was obtained with immunosuppressive therapy. The initial clinical presentation and subsequent remission under immunosuppressive therapy were suggestive of a vasculitis with nervous system involvement. Though vasculitis was not proven histologically in this patient, we believe that MPO-ANCA-related autoimmunity provoked the patient's disease as already reported in similar cases. As pachymeningitis is a fibrosing process, early recognition and treatment of an autoimmune etiology, even in the absence of previous pulmonary or renal involvement, is required to prevent definitive neurological impairment.