原発性中枢神経血管炎

Primary Central Nervous System Vasculitis

原発性中枢神経血管炎は，脳や脊髄に限局する原因不明の血管炎である。原発性中枢神経血管炎の診断には，脳組織所見や脳血管造影所見に加えて，感染症や全身性疾患による二次性血管炎の除外を目的とした全身検索が必要とされる。かつては治療抵抗性で予後不良と考えられていたが，ステロイドやシクロホスファミドによる急性期治療や寛解維持療法を適切に選択することで，良好な転帰が得られることがわかってきた。

Abstract

Primary central nervous system (CNS) vasculitis is an uncommon disorder of unknown etiology that is restricted to the brain and spinal cord. Patients do not present with specific clinical features or a classical clinical course, and no blood or imaging investigations are available for diagnostic confirmation. Cerebral biopsy and angiography are the gold standards for diagnosis. No randomized clinical trials have described a therapeutic regimen effective for primary CNS vasculitis; therefore, treatment of primary CNS vasculitis is based on therapeutic strategies used for other types of vasculitis. Early diagnosis is important because corticosteroid-based treatment with or without concomitant cyclophosphamide administration can often prevent serious outcomes and may be followed by a favorable response. Several immunosuppressants such as mycophenolate mofetil, tumor necrosis factor-α blockers, and rituximab may be useful options for patients refractory to the aforementioned regimen. We describe some diagnostic and therapeutic approaches for the management of this condition, with a focus on the importance of obtaining tissue and angiographic evaluation (formal contrast-enhanced or magnetic resonance/computed tomography angiography).