Neurological examination in healthy term infants aged 3-10 weeks.

OBJECTIVES

The neurodevelopmental progress of newborn term infants is checked routinely at around 6 weeks of postnatal age. The maturation of neurological signs in this age range however has not been systematically studied and normative data are not available. The aim of this study was to document any changes in posture, tone, reflexes, behaviour and movements in low-risk full-term infants between 3 and 10 weeks of postnatal age.

STUDY

DESIGN

We performed a structured neurological examination previously standardised in full-term newborns in the first 48 h after birth. In the current study, a total of 76 examinations were performed between 3 and 10 weeks of age in low-risk full-term infants.

RESULTS

The results of the examinations were divided according to postnatal age. In most items, the scores changed with time, with a definite shift in their distribution occurring around 6 weeks. At this age, a reduction in flexor tone of the limbs was observed, together with an increase in active neck tone. Visual orientation in contrast had already improved by 3 weeks when all infants were able to follow a target in a full circle compared to newborns that are often only able to follow a target in an arc.

CONCLUSIONS

Our results suggest that 6 weeks post-term birth is an important milestone for changes in neurological signs, particularly those related to muscle tone and posture, probably reflecting maturation of the nervous system. These findings provide important guidelines for the interpretation of the neurological examination performed at this age.