title: Adult primary angiitis of the central nervous system: isolated small-vessel vasculitis represents distinct disease pattern.
abstract: We aimed to identify whether presentations and outcomes in adult patients with isolated small-vessel primary angiitis of the CNS (PACNS) would differ from other patients with large/medium-vessel involvement.
  
  
  
  In the French PACNS cohort, we compared the characteristics, treatments and outcomes of patients with isolated small-vessel disease (normal CT, MR and/or conventional angiograms, brain biopsy positive for vasculitis) with other patients who had large/medium-vessel involvement (vessel abnormalities on CT, MR or conventional angiograms). A good functional outcome was defined as a modified Rankin scale ⩽2 at last follow-up, regardless of the occurrence of relapse.
  
  
  
  Among the 102 patients in the cohort, 26 (25%) had isolated small-vessel PACNS, whereas the 76 others demonstrated large/medium-vessel involvement. Patients with isolated small-vessel PACNS had more seizures (P < 0.0001), cognitive (P = 0.02) or consciousness impairment (P = 0.03) and more dyskinesias (P = 0.002) but less focal deficits (P = 0.0002) than other PACNS patients. They also had more abnormal cerebrospinal fluid analysis (P = 0.008) and gadolinium enhancements on MRI (P = 0.001) but less frequent acute ischaemic lesions (P < 0.0001) than patients with large/medium-vessel involvement. Treatments and modified Rankin scale at last follow-up did not differ between groups. Thirty-two (31%) patients relapsed; 14 (54%) with isolated small-vessel PACNS vs 18 (24%) with large/medium-vessel involvement (P = 0.004). Eight patients died, with no difference between the groups (P = 0.97).
  
  
  
  In our cohort, adult patients with isolated small-vessel PACNS presented some distinct disease features and relapsed more often than other PACNS patients who had large/medium-vessel involvement. Functional outcomes and mortality did not differ.
authors.affiliation: Department of Internal Medicine, Caen University Hospital, University of Caen - Basse Normandie, Caen.
authors.forename: Hubert
authors.initials: H
authors.lastname: de Boysson
authors.affiliation: Department of Neuroradiology, Sainte-Anne Hospital Center, AP - HP, University Paris-Descartes, INSERM UMR 894.
authors.forename: Grégoire
authors.initials: G
authors.lastname: Boulouis
authors.affiliation: Department of Internal Medicine, Caen University Hospital, University of Caen - Basse Normandie, Caen.
authors.forename: Achille
authors.initials: A
authors.lastname: Aouba
authors.affiliation: Department of Internal Medicine, Caen University Hospital, University of Caen - Basse Normandie, Caen.
authors.forename: Boris
authors.initials: B
authors.lastname: Bienvenu
authors.affiliation: Department of Internal Medicine, Cochin Hospital Center, AP - HP.
authors.forename: Loïc
authors.initials: L
authors.lastname: Guillevin
authors.affiliation: Department of Neurology, Saint-Joseph Hospital Center, AP - HP, Université Paris-Descartes, INSERM UMR S 919, Paris.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Zuber
authors.affiliation: Department of Neurology, Caen University Hospital.|Inserm U919, University of Caen - Basse Normandie, Caen, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Touzé
authors.affiliation: Department of Neuroradiology, Sainte-Anne Hospital Center, AP - HP, University Paris-Descartes, INSERM UMR 894.
authors.forename: Olivier
authors.initials: O
authors.lastname: Naggara
authors.affiliation: Vasculitis Clinic, Division of Rheumatology, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Christian
authors.initials: C
authors.lastname: Pagnoux
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001921:Brain / Q000473:pathology; D016022:Case-Control Studies; D002533:Cerebral Angiography; D059345:Cerebral Small Vessel Diseases / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D060825:Cognitive Dysfunction / Q000209:etiology; D015331:Cohort Studies; D003244:Consciousness Disorders / Q000209:etiology; D020820:Dyskinesias / Q000209:etiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D012189:Retrospective Studies; D012640:Seizures / Q000209:etiology; D014057:Tomography, X-Ray Computed; D020293:Vasculitis, Central Nervous System / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D055815:Young Adult
keywords: MRI; biopsy; large/medium vessel; primary angiitis of the central nervous system; relapse; small vessel