Diffusion tensor imaging of the pyramidal tracts in infants with motor dysfunction.
OBJECTIVE
To determine if diffusion tensor imaging (DTI) metrics of the pyramidal tracts correlate with motor outcome in infants presenting with motor dysfunction.


METHODS
DTI tractography of the pyramidal tracts was performed in 21 patients with clinical motor dysfunction who were less than 30 months of age and in 22 age-matched controls. We plotted tract-specific DTI metrics (fractional anisotropy, parallel diffusivity, transverse diffusivity, and mean diffusivity) against age for the controls and generated normative curves. For each patient, we calculated the deviation from the normative curves. Patients returned for a neurodevelopmental evaluation when they were over 36 months of age, and motor outcome measures were performed. We analyzed the association between normative deviation in DTI metrics and motor outcome measures using linear and logistic regression models.


RESULTS
Normative deviation in fractional anisotropy and transverse diffusivity were significantly correlated with all measures of motor outcome. Lower fractional anisotropy and higher transverse diffusivity compared to controls were associated with worse motor outcome. Furthermore, children who were eventually diagnosed with permanent motor dysfunction had lower fractional anisotropy and higher transverse diffusivity compared with those whose motor dysfunction normalized.


CONCLUSIONS
Diffusion tensor imaging metrics correlate with motor outcome in infants presenting with motor dysfunction. The identification of a quantitative imaging marker that can be applied to infants at the time of clinical presentation has implications for the evaluation of early motor dysfunction.
Ludeman
N A
NA
Department of Radiology, University of California San Francisco, San Francisco, CA 94143-0628, USA.
Berman
J I
JI
Wu
Y W
YW
Jeremy
R J
RJ
Kornak
J
J
Bartha
A I
AI
Barkovich
A J
AJ
Ferriero
D M
DM
Henry
R G
RG
Glenn
O A
OA
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D009069:Movement Disorders / Q000175:diagnosis*; D011712:Pyramidal Tracts / Q000473:pathology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D055815:Young Adult