title: [Aetiological classification of ischaemic strokes: comparison of the new A-S-C-O classification and the classification by the Spanish Society of Neurology's Cerebrovascular Disease Study Group].
abstract: BACKGROUND
  The A-S-C-O classification may be better than other methods for classifying ischaemic stroke by aetiology. Our aims are to describe A-S-C-O phenotype distribution (A: atherosclerosis, S: small vessel disease, C: cardiac source, O: other causes; 1: potential cause, 2: causality uncertain, 3: unlikely to be a direct cause although disease is present) and compare them to the Spanish Society of Neurology's Cerebrovascular Disease Study Group (GEECV/SEN) classification. We will also find the degree of concordance between these classification methods and determine whether using the A-S-C-O classification delivers a smaller percentage of strokes of undetermined cause.
  
  
  METHODS
  We analysed those patients with ischaemic stroke admitted to our stroke unit in 2010 with strokes that were classified according to GEECV/SEN and A-S-C-O criteria.
  
  
  RESULTS
  The study included 496 patients. The percentages of strokes caused by atherosclerosis and small vessel disease according to GEECV/SEN criteria were higher than the percentages for potential atherosclerotic stroke (A1) (14.1 vs. 11.9%; P=.16) and potential small vessel stroke (S1) (14.3 vs. 3%; P<.001). Cardioembolic stroke (C1) was more frequent (22.2 vs. 31%; P<.001). No differences between unusual cause of stroke and other potential causes (O1) were observed. Some degree of atherosclerosis was present in 53.5% of patients (A1, A2, or A3); 65.5% showed markers of small vessel disease (S1, S2, or S3), and 74.9% showed signs of cardioembolism (C1, C2, or C3). Fewer patients in the group without scores of 1 or 2 for any of the A-S-C-O phenotypes were identified as having a stroke of undetermined cause (46.6 vs. 29.2%; P<.001). The agreement between the 2 classifications ranged from κ<0.2 (small vessel and S1) to κ>0.8 (unusual causes and O1).
  
  
  CONCLUSIONS
  Our results show that GEECV/SEN and A-S-C-O classifications are neither fully comparable nor consistent. Using the A-S-C-O classification provided additional information on co-morbidities and delivered a smaller percentage of strokes classified as having an undetermined cause.
authors.affiliation: Unidad de Ictus, Servicio de Neurología, Hospital General Universitario Gregorio Marañón, Madrid, España. Electronic address: pilarsobrino@live.com.
authors.forename: P
authors.initials: P
authors.lastname: Sobrino García
authors.forename: A
authors.initials: A
authors.lastname: García Pastor
authors.forename: A
authors.initials: A
authors.lastname: García Arratibel
authors.forename: G
authors.initials: G
authors.lastname: Vicente Peracho
authors.forename: P M
authors.initials: PM
authors.lastname: Rodriguez Cruz
authors.forename: J R
authors.initials: JR
authors.lastname: Pérez Sánchez
authors.forename: F
authors.initials: F
authors.lastname: Díaz Otero
authors.forename: P
authors.initials: P
authors.lastname: Vázquez Alén
authors.forename: J A
authors.initials: JA
authors.lastname: Villanueva Osorio
authors.forename: A
authors.initials: A
authors.lastname: Gil Núñez
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000150:complications; D002545:Brain Ischemia / Q000145:classification* / Q000150:complications; D059345:Cerebral Small Vessel Diseases / Q000150:complications; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000150:complications; D002546:Ischemic Attack, Transient / Q000145:classification / Q000150:complications; D008297:Male; D008875:Middle Aged; D013030:Spain; D020521:Stroke / Q000145:classification* / Q000150:complications / Q000209:etiology