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Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale
Published on: August 25, 2014
Neurological examination in healthy term infants aged 3-10 weeks
Andrea Guzzetta1, Leena Haataja, Frances Cowan
1Department of Paediatrics, Imperial College School of Medicine, Hammersmith Campus, London, UK. a.guzzetta@inpe.unipi.it
Insights
Around 6 weeks, infants show significant neurological changes in muscle tone and posture, marking a key developmental milestone. This study provides normative data for assessing infant neurological development at this crucial stage.
Area of Science:
- Neuroscience
- Developmental Pediatrics
- Neonatology
Background:
- Routine neurodevelopmental assessments for term infants occur around 6 weeks postnatal.
- Systematic studies on neurological sign maturation and normative data for this age group are lacking.
Purpose of the Study:
- To document changes in posture, tone, reflexes, behavior, and movements in low-risk, full-term infants.
- To establish normative data for neurological examinations between 3 and 10 weeks postnatal.
Main Methods:
- A structured neurological examination, previously standardized for newborns, was used.
- 76 examinations were conducted on low-risk, full-term infants between 3 and 10 weeks of age.
Main Results:
- Neurological examination scores showed changes over time, with a significant shift around 6 weeks.
- Flexor tone decreased, while active neck tone increased by 6 weeks.
- Visual orientation improved by 3 weeks, with infants tracking targets in a full circle.
Conclusions:
- Six weeks postnatal is a critical milestone for neurological sign maturation, particularly muscle tone and posture.
- Findings offer guidelines for interpreting neurological examinations in infants around 6 weeks.
- The study highlights the rapid neurodevelopment occurring in early infancy.
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.
