Introduction: Primary angiitis of central nervous system (PACNS) typically manifests with accumulating small-sized ischemic strokes and white-matter changes. Large-artery infarcts (LA-PACNS) have been observed, however it is unclear whether LA-PACNS is a unique subtype.
Methods: We compared the clinical/imaging phenotype, predictors, treatment response and prognosis of LA-PACNS and small-vessel PACNS (SV-PACNS) from a cohort of 51 cases meeting published criteria for PACNS (Ann Neurol. 2016;79:882-94) who were managed at our hospital from 1993-2015.
Results: Overall mean age 51±15 years; 72% men. Six patients (12%, 95% CI: 3%-21%; mean age 55±13 years; 67% men) had LA-PACNS; 4 (67%) presented with discrete stroke syndromes versus 49% in SV-PACNS. The frequency of headache, encephalopathy, seizure and focal deficits were not significantly different however LA-PACNS had more hypertension. CSF, performed in all patients, showed inflammatory changes in 63% SV-PACNS versus 33% LA-PACNS (p=0.4). Brain biopsy was performed in 5 LA-PACNS and 32 SV-PACNS. In LA-PACNS, one had granulomatous angiitis (GACNS), one had amyloid-beta related angiitis (ABRA), and 3 had negative results. In SV-PACNS, 18 (56%) showed abnormal results including lymphocytic/chronic (12), GACNS (5), ABRA (1). There were no significant differences in the frequency of angiographic abnormalities (67% vs 53%), arteriopathy severity score (10±10 vs 8±13), or arterial segment involved. There were no significant differences in the degree of white matter change, microbleeds, or contrast enhancement on MRI however LA-PACNS had more FLAIR dot sign indicating slow flow and collateralization in leptomeningeal arteries (40% vs 5%, p=0.05). Except for two patients with SV-PACNS, all were treated with steroids; 23 SV-PACNS and all LA-PACNS also received cyclophosphamide. The interval from onset to diagnosis was shorter in LA-PACNS (42 vs 110 days) and follow-up duration was similar (5.4±7.5 years vs. 5.9±6.3 years). Mortality (33% LA-PACNS vs 16% SV-PACNS) and full remission (50% vs 62%) were not significantly different.
Conclusions: In our relatively large cohort of PACNS, LA-PACNS and SV-PACNS showed similar clinical, imaging, angiographic features and outcome.