title: Corticospinal tract pre-wallerian degeneration: a novel outcome predictor for pediatric stroke on acute MRI.
abstract: OBJECTIVE
  In neonatal arterial ischemic stroke, pre-Wallerian degeneration in descending corticospinal tracts (DCST) on diffusion MRI (DWI) predicts poor outcome. This signal has not been studied in older children.
  
  
  METHODS
  A consecutive arterial ischemic stroke cohort (1 month to 18 years) with acute DWI and >12 months of follow-up were enrolled (SickKids Children's Stroke Program). DCST-DWI variables were quantified with a validated software technique and correlations to the Pediatric Stroke Outcome Measure were sought.
  
  
  RESULTS
  Abnormal DCST-DWI signal was detected in 20 of 29 children (69%), with 85% having motor deficits on Pediatric Stroke Outcome Measure. DCST variables correlated with hemiparesis included: (1) any abnormal signal within the course of the DCST; (2) midbrain location; (3) percentage of peduncle; (4) vertical length; and (5) relative volume affected (all P<0.003). Unexpectedly, abnormal DWI signal was detected in the contralesional DCST in 7 children, all with severe hemiparesis. DCST signal abnormality increased over time, outlasted infarct DWI changes, and was difficult to appreciate on visual inspection.
  
  
  CONCLUSIONS
  DCST-DWI signal is an acute predictor of motor outcome in childhood stroke and can help guide management. Previously unrecognized contralesional DCST signal predicts severe hemiparesis.
authors.affiliation: Children's Stroke Program, The Hospital for Sick Children and Institute for Medical Science, University of Toronto, Toronto, ON, Canada.
authors.forename: Trish
authors.initials: T
authors.lastname: Domi
authors.forename: Gabrielle
authors.initials: G
authors.lastname: deVeber
authors.forename: Manohar
authors.initials: M
authors.lastname: Shroff
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Kouzmitcheva
authors.forename: Daune L
authors.initials: DL
authors.lastname: MacGregor
authors.forename: Adam
authors.initials: A
authors.lastname: Kirton
mesh_terms: D000293:Adolescent; D002545:Brain Ischemia / Q000150:complications; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010291:Paresis / Q000209:etiology / Q000503:physiopathology; D011379:Prognosis; D011712:Pyramidal Tracts / Q000473:pathology*; D020521:Stroke / Q000473:pathology* / Q000628:therapy*; D016896:Treatment Outcome; D014855:Wallerian Degeneration / Q000473:pathology*