Quantified corticospinal tract diffusion restriction predicts neonatal stroke outcome.
OBJECTIVE
Neonatal arterial ischemic stroke occurs in > or =1:4000 births. Many children experience motor deficits but acute predictors of outcome are lacking. Diffusion-weighted MRI changes in descending corticospinal tracts remote from arterial ischemic stroke may represent pre-Wallerian degeneration. We verify and quantify this signal and correlate it with motor outcome.


METHODS
Fourteen neonates with acute arterial ischemic stroke and > or =12 months follow-up with the Pediatric Stroke Outcome Measure were included. Quantitative measurements of descending corticospinal tracts diffusion-weighted MRI signal were developed using Image J software.


RESULTS
Ipsilesional descending corticospinal tract diffusion-weighted MRI signal was abnormal in 10 neonates with decreased apparent diffusion coefficients (P<0.001). Poor outcome correlated with: (1) percentage of peduncle (P=0.002); (2) length of descending corticospinal tracts P<0.001); and (3) volume of descending corticospinal tracts (P=0.002). None of: (1) any peduncle; (2) any posterior limb of the internal capsule; or (3) infarct volume correlated with outcome. All children without descending corticospinal tracts signal had normal outcome. Chronic Wallerian degeneration was seen in all children with hemiparesis. Software-assisted analysis was superior to visual inspection with excellent reliability (intra-class correlation coefficient > or =0.9).


CONCLUSIONS
Descending corticospinal tracts diffusion-weighted MRI signal is predictive of motor outcome from neonatal arterial ischemic stroke. This accurate, reliable, and simple tool will impact decision making in acute neonatal stroke.
Kirton
Adam
A
Children's Stroke Program, Division of Neurology, Hospital for Sick Children, Toronto, ON, Canada. adam.kirton@sickkids.ca
Shroff
Manohar
M
Visvanathan
Tharshini
T
deVeber
Gabrielle
G
D015331:Cohort Studies; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011237:Predictive Value of Tests; D011712:Pyramidal Tracts / Q000000981:diagnostic imaging*; D011859:Radiography; D020521:Stroke / Q000000981:diagnostic imaging* / Q000453:epidemiology; D016896:Treatment Outcome