Primary CNS Vasculitis
Primary CNS vasculitis causes inflammation of mostly small- to medium-sized leptomeningeal and parenchymal arterial vessels. It is rare—a 2007 retrospective analysis by Salvarani et al of 101 cases estimated the average annual incidence to be 2.4 cases per one million person-years. Onset tends to occur in middle age, with a median age at diagnosis of 50 and a similar frequency in males and females.
Clinical presentation of PCNSV can be acute, subacute, chronic, or recurrent. Depending on the area of the brain or spinal cord that is affected, patients can present with a wide variety of neurologic complaints. Headache is the most common symptom—found in 50% to 78% of patients—followed by altered cognition and persistent neurologic deficits. Stroke and transient ischemic attack involving multiple vascular areas occur in 30% to 50% of patients.
The diagnostic gold standard for PCNSV is brain parenchymal/leptomeningeal biopsy. The most common diagnoses are granulomatous angiitis of the CNS (58%), lymphocytic PACNS (28%), and necrotizing vasculitis (14%). More than 90% of patients have abnormalities on MRI, and the most common imaging findings are cortical and subcortical infarcts, leptomeningeal enhancement, intracranial hemorrhage, and areas of increased signal on FLAIR and T2-weighted sequences. It has been increasingly recognized that differential diagnosis for PCNSV should include reversible cerebral vasoconstriction syndrome (RCVS), which is characterized by reversible multifocal narrowing of the cerebral arteries—typically preceded by sudden, severe thunderclap headaches with or without associated neurologic deficits. RCVS typically resolves in approximately 12 weeks.
Regarding treatment for PCNSV, Dr. Pawate recommended starting with high-dose steroids—eg, IV methylprednisolone, 1,000 mg daily for five days, with a prolonged oral prednisone taper starting at 1 mg/kg/day—and six to nine months of IV cyclophosphamide pulse therapy, 500–750 mg/m2 every two to four weeks for more severe cases. Case studies have shown rituximab and mycophenolate to be effective. “I had one patient initially on cyclophosphamide for six months who we [then] maintained on mycophenolate for five years and then stopped immunosuppression,” Dr. Pawate said. “She did quite well.”
—Fred Balzac
Suggested Reading
Abdel Razek AA, Alvarez H, Bagg S, et al. Imaging spectrum of CNS vasculitis. Radiographics. 2014;34(4):873-894.
Chow FC, Marra CM, Cho TA. Cerebrovascular disease in central nervous system infections. Semin Neurol. 2011;31(3):286-306.
Hajj-Ali RA, Calabrese LH. Diagnosis and classification of central nervous system vasculitis. J Autoimmun. 2014;48-49:149-152.
Jennette JC, Falk RJ, Bacon PA, et al. 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides. Arthritis Rheum. 2013;65(1):1-11.
Salvarani C, Brown RD Jr, Calamia KT, et al. Primary central nervous system vasculitis: analysis of 101 patients. Ann Neurol. 2007;62(5):442-451.
Scolding NJ. Central nervous system vasculitis. Semin Immunopathol. 2009;31(4):527-536.