[Relationship between the growth rate of corpus callosum and neuromotor delay in premature infants].

OBJECTIVE: To study the relationship between the growth rate of the corpus callosum and neurological motor development in premature infants. METHODS: Fifty infants whose gestational ages were less than 34 weeks and who were admitted to the neonatal intensive care unit from March 2007 to August 2007 were enrolled. From 0 to 6 weeks of postnatal age, the sagittal midline cranial sonography via anterior fontanel was performed, once weekly. The length and the morphology of the corpus callosum were measured. The 52-neuromotor examinations were performed at 3 months of corrected gestational age. RESULTS: The mean length of the corpus callosum was 39.16 mm at birth. The mean growth rate of the corpus callosum during the first 6 weeks of life was 1.05 mm/week. Fourteen infants showed abnormal neuromotor development and 36 had normal-neuromotor function at 3 months of corrected gestational age. A decreased growth rate of the corpus callosum was observed in the abnormal nervimotion group between 2 and 3 weeks (0.68 mm/week vs 1.17 mm/week) and between 4 and 5 weeks (0.86 mm/week vs 1.12 mm/week) after birth compared with that in normal nervimotion group (p<0.05). The total growth rate of the corpus callosum from 2 to 6 weeks after birth in the abnormal nervimotion group was also lower than that in the normal nervimotion group (0.91 mm/week vs 1.15 mm/week; p<0.01). CONCLUSIONS: A neuromotor delay at 3 months of corrected gestational age may be associated with the decreased growth rate of the corpus callosum between 2 and 6 weeks of life in premature infants.

Ultrasound measurement of the corpus callosum and neural development of premature infants.

Length and thickness of 152 corpus callosa were measured in neonates within 24 hours of birth. Using ultrasonic diagnostic equipment with a neonatal brain-specific probe, corpus callosum length and thickness of the genu, body, and splenium were measured on the standard mid-sagittal plane, and the anteroposterior diameter of the genu was measured in the coronal plane. Results showed that corpus callosum length as well as thickness of the genu and splenium increased with tional age and birth weight, while other measures did not. These three factors on the standard mid-sagittal plane are therefore likely to be suitable for real-time evaluation of corpus callosum velopment in premature infants using cranial ultrasound. Further analysis revealed that thickness of the body and splenium and the anteroposterior diameter of the genu were greater in male infants than in female infants, suggesting that there are sex differences in corpus callosum size during the neonatal period. A second set of measurements were taken from 40 premature infants whose gestational age was 34 weeks or less. Corpus callosum measurements were corrected to a gestational age of 40 weeks, and infants were grouped for analysis depending on the outcome of a neonatal behavioral neurological assessment. Compared with infants with a normal neurological assessment, corpus callosum length and genu and splenium thicknesses were less in those with abnormalities, indicating that corpus callosum growth in premature infants is associated with neurobehavioral development during the early extrauterine stage.