Current and future advances in practice: a practical approach to the diagnosis and management of primary central nervous system vasculitis

Abstract

Primary CNS vasculitis (CNSV) is a rare, idiopathic autoimmune disease that, if untreated, can cause significant morbidity and mortality. It is a challenging diagnosis due to multiple mimics that can be difficult to differentiate, given that the CNS is an immunologically privileged and structurally isolated space. As such, diagnosis requires comprehensive multimodal investigations. Usually, a brain biopsy is required to confirm the diagnosis. Treatment of CNSV involves aggressive immunosuppression, but relapses and morbidity remain common. This expert review provides the reader with a deeper understanding of presentations of CNSV and the multiple parallel diagnostic pathways that are required to diagnose CNSV (and recognize its mimics), highlights the important knowledge gaps that exist in the disease and also highlights how we might be able to care for these patients better in the future.

Keywords: brain biopsy; central nervous system; collaborative care; neuroradiology; vasculitis.

Figure 1.

Radiographic findings of primary CNS vasculitis. (A, B) Pre- (A) and post-gadolinium (B) T1 SPACE high-resolution MR-VWI shows circumferential vessel wall enhancement (B, arrow) in a patient with suspected CNSV. (C) 7 T MR-VWI following gadolinium administration shows diffuse pericallosal artery branch wall enhancement in biopsy-proven CNSV (arrows). (D) FLAIR MRI showing evolving signal changes from parenchymal insults of varying ages, including subacute (arrowhead) and acute (arrow). (E) diffusion-weighted MRI in the same patient as (E) shows that the paramedian frontal insult is acute. (F) Digital subtraction angiography in the same patient showing subtle areas of distal anterior cerebral artery territory beaded luminal irregularity. CNSV: CNS vasculitis; FLAIR: fluid-attenuated inversion recovery; VW: vessel wall

Figure 2.

Mimics of CNS vasculitis seen with magnetic resonance vessel wall imaging (MR-VWI). (A, B) Before (A) and after (B) T1 SPACE high-resolution MR-VWI showing an area of eccentric M2 wall thickening and enhancement (arrow) related to non-inflammatory atherosclerotic changes. (C) Post-gadolinium coronal T1 SPACE MR-VWI showing vasa vasorum enhancement of the proximal V4 segments in atherosclerotic disease (often mistaken as inflammation). (D–G) Images representing distal M1 thrombosis with a finding of circumferential enhancement (G) secondary to thrombectemy: area of apparent filling defect in the right cavernous ICA segment (D, arrow) owing to flow-related artefact, with E showing patency on time-of-flight (TOF) magnetic resonance angiography; CTA demonstrating acute distal right M1 occlusion (F, arrow) and G showing MR-VWI following mechanical thrombectomy, with circumferential enhancement thought to be related to mechanical manipulation and disruption of the endothelium. (H, I) Images from a patient with reversible cerebral vasoconstriction syndrome with multifocal areas of luminal narrowing (H) of the proximal M2 on CTA (arrows) and absence of vessel wall enhancement (I) in the same region on MR-VWI suggesting a diagnosis of reversible cerebral vasoconstriction syndrome. CNSV: CNS vasculitis; CTA: CT angiography