[Evaluation of relationship between early brain response and neurodevelopment in newborns by using near infrared spectroscopy].

OBJECTIVE

To study the relationship between early brain response to extrinsic stimulation and neurodevelopment in preterm infants, assess the brain function of preterm infants in the early stage, and thereby to provide objective evidence for the degree of neurodevelopment in preterm infants and to evaluate prognosis.

METHODS

Using near infrared spectroscopy (NIRS), the brain response to sound stimulation of 90 preterm infants at different gestational age was observed and compared with the result obtained from 20 full term infants. The neonatal behavioral neurological assessment (NBNA) was performed at corrected age of 40 weeks, and the infants were followed up for 2 years. The effect of gestational age and brain damage on preterm infants, the relation between early brain response in preterm infants and their neurodevelopment was evaluated.

RESULTS

All the preterm infants responded to different degrees to auditory stimulation after birth. The time to beginning to react and the time to appearance of the peak reaction were attained after auditory stimulation and the time to beginning to resume when the auditory stimulation was stopped was (278 +/- 94) s, (446 +/- 67) s and (199 +/- 52) s, respectively, which were significantly longer than those observed in the full term infants (107 +/- 30) s, (264 +/- 51) s and (131 +/- 46) s, respectively. The maximum reactions of hemoglobin, oxyhemoglobin and regional oxygen saturation in the infants after gestational age 32 weeks was (0.3 +/- 0.3)%, (0.7 +/- 0.5)% and (0.3 +/- 0.3)%, respectively, which were significantly lower than those in the full term infants (1.7 +/- 0.7)%, (1.7 +/- 0.8)% and (1.6 +/- 0.7)%, respectively. When the brain response of preterm infants was compared with that in infants without brain damage, the speed of the reaction was slow, the maximum reaction was low. The brain response in preterm infant was correlated with NBNA at corrected age of 40 weeks. It was found during the following-up that abnormal neurodevelopment was associated with poor brain reaction.

CONCLUSIONS

NIRS can be used to evaluate brain response of infants. Preterm infants display brain response to auditory stimulation. Early brain response is correlated with neurodevelopment.