title: Morphological classification of penetrating artery pontine infarcts and association with risk factors and prognosis: The SPS3 trial.
abstract: Pontine infarcts are common and often attributed to small vessel disease ("small deep infarcts") or basilar branch atherosclerosis ("wedge shaped"). A well-described morphological differentiation using magnetic resonance images has not been reported. Furthermore, whether risk factors and outcomes differ by morphology, or whether infarct morphology should guide secondary prevention strategy, is not well characterized.
  
  
  
  All participants in the Secondary Prevention of Small Subcortical Strokes Study with magnetic resonance imaging -proven pontine infarcts were included. Infarcts were classified as well-circumscribed small deep (small deep infarct, i.e. lacunar), paramedian, atypical paramedian, or other based on diffusion-weighted imaging, T2/fluid-attenuated inversion recovery, and T1-magnetic resonance images. Inter-rater reliability was high (90% agreement, Cohen's kappa = 0.84). Clinical and radiologic features independently associated with small deep infarct versus paramedian infarcts were identified (multivariable logistic regression). Differences in stroke risk and death were assessed using Cox proportional hazards.
  
  
  
  Of the 3020 patients enrolled, 644 had pontine infarcts; 619 images were available: 302(49%) small deep infarct, 245 (40%) paramedian wedge, 35 (6%) atypical paramedian, and 37 (6%) other. Among vascular risk factors, only smoking (OR 2.1, 95% CI 1.3-3.3) was independently associated with small deep infarct versus paramedian infarcts; on neuroimaging, old lacunes on T1/fluid-attenuated inversion recovery (OR 1.8, 1.3-2.6) and intracranial stenosis (any location) ≥50% (OR 0.62, 0.41-0.96). Small deep infarct versus paramedian was not predictive of either recurrent stroke or death, and there was no interaction with assigned treatment.
  
  
  
  Pontine infarcts can be reliably classified based on morphology using clinical magnetic resonance images. Few risk factors differed between small deep infarct and paramedian infarcts with no differences in recurrent stroke or mortality. There was no difference in response to different antiplatelet or blood pressure treatment strategies between these two groups.
  
  
  
  http://www.clinicaltrials.gov/NCT00059306.
authors.affiliation: Center for Brain Health, and Division of Neurology, University of British Columbia, Vancouver BC Canada.
authors.forename: Laura K
authors.initials: LK
authors.lastname: Wilson
authors.affiliation: Biostatistics Consultant, Minot, ND, USA.
authors.forename: Lesly A
authors.initials: LA
authors.lastname: Pearce
authors.affiliation: Neurology and Neurosurgery National Institute, Mexico City, Mexico.
authors.forename: Antonio
authors.initials: A
authors.lastname: Arauz
authors.affiliation: Hennepin County Medical Center, Minneapolis, MN, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Anderson
authors.affiliation: Department of Neurology, Catholic University, Santiago, Chile.
authors.forename: Jorge
authors.initials: J
authors.lastname: Tapia
authors.affiliation: Department of Radiology, University of Texas Health Sciences Center at San Antonio, San Antonio, TX, USA.
authors.forename: Carlos
authors.initials: C
authors.lastname: Bazan
authors.affiliation: Center for Brain Health, and Division of Neurology, University of British Columbia, Vancouver BC Canada.
authors.forename: Oscar R
authors.initials: OR
authors.lastname: Benavente
authors.affiliation: Center for Brain Health, and Division of Neurology, University of British Columbia, Vancouver BC Canada thalia.field@ubc.ca.
authors.forename: Thalia S
authors.initials: TS
authors.lastname: Field
mesh_terms: D000959:Antihypertensive Agents / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use; D002544:Cerebral Infarction / Q000145:classification* / Q000000981:diagnostic imaging* / Q000188:drug therapy; D000077144:Clopidogrel; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D011149:Pons / Q000098:blood supply* / Q000000981:diagnostic imaging*; D011379:Prognosis; D012008:Recurrence; D015203:Reproducibility of Results; D012307:Risk Factors; D059409:Stroke, Lacunar / Q000145:classification / Q000000981:diagnostic imaging / Q000188:drug therapy; D013988:Ticlopidine / Q000031:analogs & derivatives / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D000959:Antihypertensive Agents; D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin
keywords: Lacunar stroke; basilar branch; cerebral small vessel disease; lacunar infarct; paramedian; penetrating artery; pons; pontine; small deep infarct