Introduction: The gold standard for diagnosis of CNS vasculitis (CNSV) is cerebral biopsy. Cerebral angiography, however, has become a common diagnostic tool for workup of this disease. Few analyses have been performed which examine the value of angiography as a stand-alone diagnostic entity or the value of cerebral biopsy in the setting of positive angiography.

Methods: A retrospective review was performed for all patients who underwent both cerebral angiography and cerebral biopsy for the workup of a presumptive diagnosis of CNSV at a single center from 2005 to 2016. The results were then subjected to statistical analyses.

Results: A total of 57 patients over the period of 2005-2016 underwent angiography for workup of presumed CNSV. Twenty patients exhibited angiograms suggestive of vasculitis and 28 patients underwent cerebral biopsy. Only one was positive. The negative predictive value (NPV) for angiography was 94.11% (CI: 71.31-99.85). Specificity was 59.26%. Positive predictive value (PPV) was unable to be calculated based on these data, given that angiography did not accurately predict biopsy diagnosis. Of note, the patient with biopsy-proven vasculitis exhibited negative angiography. Only 3.7% of biopsies were positive for vasculitis.

Conclusions: Cerebral angiography shows high NPV for CNSV. Angiography did not accurately predict diagnosis in a single case in this series. The prevalence of disease is too low to accurately ascertain PPV. Biopsy results are positive in a minority of cases, however a large percentage of patients receive steroid treatment in the face of negative results.. Cerebral biopsy may not be warranted in cases of positive angiography given the low likelihood of the disease. It may also not be indicated in cases of negative angiography given the high NPV. Surgical risks of cerebral biopsy can likely be avoided without significantly altering the course of treatment for many of these patients.

Patient Care: Ultimately it may not be necessary to subject patients to risk of cerebral biopsies; particular patients who are high risk surgical candidates due to their vasculitis.

Learning Objectives: The goal is to provoke stimulating discussion about the optimal diagnostic workup and yield for CNS vasculitis.

References: Bai HX1, Zou Y, Lee AM, Lancaster E, Yang L. Diagnostic Value and Safety of Brain Biopsy in Patients With Cryptogenic Neurological Disease: A Systematic Review and Meta-analysis of 831 Cases. Neurosurgery. 2015 Aug;77(2):283-95. Salvarani C1, Brown RD Jr, Christianson T, Miller DV, Giannini C, Huston J 3rd, Hunder GG. An update of the Mayo Clinic cohort of patients with adult primary central nervous system vasculitis: description of 163 patients. Medicine (Baltimore). 2015 May;94(21):e738.