Infectious agents reported in association with CNS vasculitis include varicella zoster virus, human immunodeficiency virus, treponema pallidum, hepatitis virus C, parvovirus B19, cytomegalovirus, Mycoplasma pneumoniae, B burgdorferi, Mycobacterium tuberculosis, Bartonella, and Rickettsiae.
Fungal infections (aspergillosis, mucormycosis, coccidioidomycosis, and candidiasis) and subarachnoid cysticercosis have also been implicated in some cases.
CNS vasculitis has also been observed in antineutrophil cytoplasmic antibody–associated vasculitis and Behçet’s syndrome. It has also been reported, although rarely, in polyarteritis nodosa, Henoch-Schonlein purpura, Kawasaki disease, giant cell arteritis, and Takayasu arteritis.
CNS vasculitis is an uncommon manifestation of neurosystemic lupus erythematosus, rheumatoid arthritis, primary Sjögren’s syndrome, dermatomyositis, and mixed connective tissue disease.
PCNSV has been associated with lymphoma, particularly Hodgkin’s disease.
Secondary CNS vasculitis also has been described in patients with neurosarcoidosis, inflammatory bowel disease, graft-versus-host disease, and with the use of some drugs (cocaine, amphetamine, ephedrine, and phenylpropanolamine).
Treatment
There are no randomized clinical trials of the medical management in PCNSV. Therefore, treatment for PCNSV has been derived from therapeutic strategies used to treat other vasculitides, anecdotal reports, and PCNSV cohort studies. The earliest reports suggested a poor prognosis with a fatal outcome in the majority of the cases, and transient or doubtful efficacy of glucocorticoids. In 1983, Cupps et al first found CYC in combination with corticosteroids to be effective in PCNSV.22 The most recent PCNSV cohort studies have described a more favorable course of PCNSV. In a study of 101 patients, a favorable response to glucocorticoids alone or in combination with CYC was achieved in 81% of the cases.1
Glucocorticoid therapy should be initiated as soon as the diagnosis of PCNSV is established. We recommend an initial dose of prednisone of 1 mg/kg/day (or equivalent) as a single or divided dose. If the patient does not respond promptly, CYC should be started. A short course of oral CYC for three to six months can also be considered for PCNSV to induce remission, as in other vasculitis. Intravenous pulses of CYC are probably safer than daily oral therapy, although it is unclear whether the two regimes differ in terms of efficacy in PCNSV. After initial treatment with prednisone and cytoxan, one can consider a lower-risk immunosuppressant such as azathioprine, methotrexate, or mycophenolate mofetil (MMF) for maintenance of remission. A treatment course of 12 to 18 months appears adequate in the majority of cases.
Tumor necrosis factor–α (TNF-α) blockers and MMF have successfully been used to treat patients with PCNSV resistant to glucocorticoids and immunosuppressives.23,24 Anti-CD20 therapy with rituximab has been used successfully in refractory granulomatosis with polyangiitis (Wegener’s) involving the CNS, suggesting a possible role for this drug in treating PCNSV.25