title: The different maturation of the corticospinal tract and corticoreticular pathway in normal brain development: diffusion tensor imaging study.
abstract: OBJECTIVE
  The corticospinal tract (CST) and corticoreticular pathway (CRP) are known to be important neural tracts for motor development. However, little is known about the difference in maturation of the CST and CRP. In this study, using diffusion tensor imaging (DTI), we investigated maturation of the CST and CRP in typically developed children and normal healthy adults.
  
  
  METHODS
  We recruited 75 normal healthy subjects for this study. DTI was performed using 1.5-T, and the CST and CRP were reconstructed using DTI-Studio software. Values of fractional anisotropy (FA) and fiber volume (FV) of the CST and CRP were measured.
  
  
  RESULTS
  In the current study, the threshold points for CST and CRP maturation were different in normal brain development. Change in FA value of the CST showed a steep increase until 7 years of age and then a gradual increase until adulthood, however, the CRP showed a steep increase only until 2 years of age and then a very gradual increase or plateau until adulthood. In terms of FV, the CST showed a steep increase until 12 years and then a gradual increase until adulthood, in contrast, the CRP showed gradual increase of FV across whole age range (0-25 years).
  
  
  CONCLUSIONS
  The difference in maturation process between CST and CRP appears to be related to different periods of fine and gross motor development. This radiologic information can provide a scientific basis for understanding development in motor function.
authors.affiliation: Department of Physical Therapy, College of Health Sciences, Dankook University Cheonan, South Korea.
authors.forename: Sang Seok
authors.initials: SS
authors.lastname: Yeo
authors.affiliation: Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University Taegu, South Korea.
authors.forename: Sung Ho
authors.initials: SH
authors.lastname: Jang
authors.affiliation: Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University Taegu, South Korea.
authors.forename: Su Min
authors.initials: SM
authors.lastname: Son
keywords: brain; corticoreticular pathway; corticospinal tract; maturation; motor