Cerebral angiitis revealing granulomatosis with polyangiitis: a case report

Cerebral vasculitis are rare conditions whose diagnosis remains complex due to the diversity of clinical and radiological presentations. We report the case of a young patient with recurrent febrile headaches revealing a unilateral stenosis of the left middle cerebral artery, associated with an angiographic aspect of « Moyamoya-like » type. The clinical course, marked by the appearance of right hypoacusis and the secondary positivity of anti-PR3 ANCA, led to the diagnosis of granulomatosis with polyangiitis (GPA) at inaugural cerebral expression. This observation illustrates the possible double pathophysiology of neurological involvement in GPA: inflammatory vasculitis and granulomatous infiltration. The «Moyamoya-like» aspect, rarely reported, could reflect a collateral mechanism for a localized inflammatory stenosis. This case highlights the importance of a multidisciplinary evaluation, the use of serial vascular imaging and prolonged immunological monitoring. The treatment is based on high-dose corticosteroids combined with an immunosuppressant, rituximab now being an effective alternative to cyclophosphamide, especially in severe neurological forms. This work highlights the rarity and clinical interest of the inaugural cerebral presentations of GPA and contributes to enrich the literature on atypical autoimmune angiopathies.