Primary angiitis of the central nervous system: neurologic deterioration despite treatment.

Primary angiitis of the central nervous system (PACNS) is an idiopathic vasculitis confined to the central nervous system. In children with PACNS, small-vessel (SV) involvement is characterized clinically by progressive neurologic symptoms, multifocal lesions on brain imaging, occasional pseudo-tumor presentation, and normal angiogram results in most patients. Small case series of patients with SV PACNS with short follow-up usually reveal favorable outcomes in children treated with immunosuppressive therapy. We report here the cases of 3 children with biopsy-confirmed SV PACNS and long-term follow-up who developed different patterns of neurologic deterioration despite immunosuppressive therapy. One patient had transient ischemic attacks shortly after initiation of corticosteroid treatment. Early ischemic events probably result from residual thrombogenicity or residual inflammation of recently affected vessels, which supports the use of antiplatelet agents and suggests potential benefits of stronger immunosuppressive therapy. In contrast, the other 2 patients had later neurologic deterioration after corticosteroid withdrawal, which suggests failure of initial immunosuppressant treatment and the need for stronger agents, longer treatment duration, or both. All patients responded to long-term treatment with corticosteroids combined with cytotoxic agents. This particular combination is probably indicated in many cases of SV PACNS, including those with neurologic deterioration that occurs during maintenance corticotherapy or after corticosteroid withdrawal. In 1 case, SV PACNS recurred several years after discontinuation of combination therapy. Long-term relapses may reflect intrinsic predispositions to SV PACNS rather than treatment failure. These cases highlight different chronological patterns of neurologic deterioration despite immunosuppressive therapy, which supports the relevance of monitoring clinical, laboratory, and radiologic responses to treatment and of long-term follow-up of patients with SV PACNS.