Corticospinal tract pre-wallerian degeneration: a novel outcome predictor for pediatric stroke on acute MRI.
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.
Domi
Trish
T
Children's Stroke Program, The Hospital for Sick Children and Institute for Medical Science, University of Toronto, Toronto, ON, Canada.
deVeber
Gabrielle
G
Shroff
Manohar
M
Kouzmitcheva
Elizabeth
E
MacGregor
Daune L
DL
Kirton
Adam
A
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*