Neurological examination of late-preterm infants at term age

Early neurological and motor function in infants born moderate to late preterm or small for gestational age at term: a prospective cohort study

BACKGROUND

There are inconsistent findings regarding neurological and motor development in infants born moderate to late preterm and infants born small for gestational age at term. The primary aim of this study was to compare neurological and motor function between preterm, term SGA and term AGA infants aged three to seven months corrected age using several common assessment tools. The secondary aim was to investigate their motor function at two years.

METHODS

In this prospective cohort study, we included 43 infants born moderate to late preterm with gestational age 32-36 + 6 weeks, 39 infants born small for gestational age (SGA) at term with a birthweight ≤ 10th centile for gestational age, and 170 infants born at term with appropriate weight for gestational age (AGA). Neurological and motor function were assessed once in infancy between three to seven months corrected age by using four standardised assessment tools: Hammersmith Infant Neurological Examination (HINE), Test of Infant Motor Performance, General Movements Assessment and Alberta Infant Motor Scale. The Ages and Stages Questionnaire (ASQ-2) was used at two years.

RESULTS

At three to seven months corrected age, mean age-corrected HINE scores were 61.8 (95% confidence interval (CI): 60.5 to 63.1) in the preterm group compared with 63.3 (95% CI: 62.6 to 63.9) in the term AGA group. Preterm infants had 5.8 (95% CI: 2.4 to 15.4) higher odds for HINE scores < 10th percentile. The other test scores did not differ between the groups. At two years, the preterm group had 17 (95% CI: 1.9 to 160) higher odds for gross motor scores below cut-off on ASQ-2 compared with the term AGA group.

CONCLUSIONS

The present study found subtle differences in neurological function between preterm and term AGA infants in infancy. At two years, preterm children had poorer gross motor function. The findings indicate that moderate prematurity in otherwise healthy infants pose a risk for neurological deficits not only during the first year, but also at two years of age when compared with term AGA children.

"The Value of Clinical Examination in Preterm Newborns after Neonatal Sepsis: A Cross-sectional Observational Study."

BACKGROUND

Neonatal sepsis is an important risk factor for lesions in the brain of preterm newborns (PTNB) and the most effective strategies to minimize its deleterious effects are early detection and intervention.

AIM

To investigate the presence of neurological abnormalities in PTNBs after neonatal sepsis.

METHODS

This was a prospective cross-sectional study with 100 PTNBs selected at random, 50 of the study group (sepsis) and 50 of the control group (non-sepsis). The neurological evaluation protocol adopted was the Hammersmith Neonatal Neurological Examination (HNNE).

RESULTS

The PTNBs of the sepsis group had total HNNE scores lower than expected for normality in 86% of the cases, and the non-sepsis group in 26% (p < .001). Higher prevalence levels of altered scores in tone category (p < .001), tone patterns (p = .026), reflexes (p = .002), movements (p < .001), abnormal signs (p < .001) and behavior (p < .001).

CONCLUSION

The neurological dysfunctions after neonatal sepsis could be identified by clinical neonatal neurological evaluation.

Phase-Based Cortical Synchrony Is Affected by Prematurity

Inter-areal synchronization by phase–phase correlations (PPCs) of cortical oscillations mediates many higher neurocognitive functions, which are often affected by prematurity, a globally prominent neurodevelopmental risk factor. Here, we used electroencephalography to examine brain-wide cortical PPC networks at term-equivalent age, comparing human infants after early prematurity to a cohort of healthy controls. We found that prematurity affected these networks in a sleep state-specific manner, and the differences between groups were also frequency-selective, involving brain-wide connections. The strength of synchronization in these networks was predictive of clinical outcomes in the preterm infants. These findings show that prematurity affects PPC networks in a clinically significant manner, suggesting early functional biomarkers of later neurodevelopmental compromise that may be used in clinical or translational studies after early neonatal adversity.

Gestational Age-Specific Distribution of the Hammersmith Neonatal Neurological Examination Scores Among Low-Risk Neonates in Ghana

OBJECTIVE

To describe gestational age-specific distribution of scores for the Hammersmith Neonatal Neurological Examination (HNNE) up to 48 h after birth in a low-risk, term-born, single-center sample in Ghana.

STUDY DESIGN

This is a nested substudy of a larger prospective study (IMPRINT: Impact of Malaria in Pregnancy on Infant Neurodevelopment) comprising 140 low-risk, term-born neonates at Korle Bu Teaching Hospital in Accra, Ghana, between November 2018 and February 2019. The sample was stratified into three gestational age groups: early-term (37 + 0-38 + 6, weeks + days; n = 61), full-term (39 + 0-40 + 6, weeks + days; n = 52), and late/post-term (41 + 0-42 + 6, weeks + days; n = 27). Neonates were administered the 34-item HNNE by trained physicians. As per the original British scoring system, raw scores for the Ghanaian sample were plotted and scores > 10th centile were assigned a score of 1, 5th-10th centile 0.5, and < 5th centile 0.

RESULTS

The range of raw scores for 16/34 HNNE items varied with gestational age. Specifically, 100% (7/7), 50% (5/10), 33% (1/3), 33% (1/3), 20% (1/5), and 14% (1/7) of items within the orientation and behavior, tone, abnormal signs/patterns, movements, tone patterns, and reflexes subdomain, respectively showed a different distribution of scores above the 10th centile across the three gestational age groups.

CONCLUSION

Differences in gestational age-specific results within our sample in comparison to the original British sample could be, albeit unlikely, due to misclassification of gestational age, unmeasured maternal or fetal morbidity, or perhaps more likely, variation in testing or test conditions, or some combination of these. Genetic variation in neurological development is also a possibility. Further research is warranted to determine the reasons for differences. Our findings highlight the need to determine the accuracy and reliability of standardized neurologic assessments in predicting neurodevelopmental risk for infants in low- and middle-income countries.

Early Neurological Assessment and Long-Term Neuromotor Outcomes in Late Preterm Infants: A Critical Review

Background and Objectives: Late preterm (LP) infants (born between 34 and 36 weeks of gestational age) are considered at higher risk of neonatal morbidities, mortality, and neurological impairments than full-term born infants (FT). The aim of this study was to provide a critical review of the literature outlining the different aspects of neurological function reported both in the neonatal period and in the follow up of late preterm infants. Materials and Methods: A comprehensive search of the MEDLINE, Embase, PsycINFO, and CINAHL electronic databases was made, using the following search terms: ‘Late preterm infants’, ‘Near term infants’, ‘neurological assessment’, ‘neurological outcome’, ‘neuromotor outcome’, cerebral palsy’, ‘CP’, ‘motor impairment’, including all the studies reporting clinical neurological assessment of LP (including both neonatal period and subsequent ages). Results: A total of 35 articles, comprising 301,495 children, were included as fulfilling the inclusion criteria: ten reported neonatal neurological findings, seven reported data about the first two years after birth, eighteen reported data about incidence of CP and motor disorder during the infancy. Results showed a more immature neurological profile, explored with structured neurological assessments, in LP infants compared with FT infants. The LP population also had a higher risk of developing cerebral palsy, motor delay, and coordination disorder. Conclusion: LP had a higher risk of neurological impairments than FT infants, due to a brain immaturity and an increased vulnerability to injury, as the last weeks of gestational age are crucial for the development of the brain.

Combined predictors of neurodevelopment in very low birth weight preterm infants

OBJECTIVE

To evaluate the combined prognostic value of neurological examination, head circumference and cranial ultrasound for neurodevelopmental delay (NDD) in very low birth weight (VLBW, <1500 g) preterm infants.

METHODS

Prospective follow-up study. Preterm infants with VLWB were assessed for NDD using the Mullen Scales of Early Learning test at 24 months of corrected age. Abnormal neurological examination (≥2 deviant items of Hammersmith neurological examination), microcephaly and major ultrasound abnormalities, each performed at term age, were evaluated as predictors of NDD in a multivariable Poisson model.

RESULTS

35/132 infants (26.5%) had NDD. In the multivariable analysis, microcephaly (RR, 3.2; 95% CI, 1.6-6.7) and major ultrasound abnormalities (RR, 2.7; 95% CI, 1.3-5.7) were associated to NDD. The combination of the two tests showed the highest positive predictive value (100%; 95% CI, 51%-100%), while the combination of normal neurological examination, no major US findings and normal head size at term showed the highest negative predictive value (89%; 95% CI, 78%-95%). The maximum under receiver operating characteristic curve area was for microcephaly or major ultrasound abnormalities (AUC 0.74 (0.65-0.83)).

CONCLUSION

The combination of head circumference, cranial ultrasound and neurological examination at term age is useful to predict NDD in VLBW preterm infants.

Late preterm births: New insights from neonatal neuroimaging and neurobehaviour

With increasing evidence of neurodevelopmental problems faced by late preterm children, there is a need to explore possible underlying brain structural changes. The use of brain magnetic resonance imaging has provided insights of smaller and less mature brains in infants born late preterm, associated with developmental delay at 2 years. Another useful tool in the newborn period is neurobehavioural assessment, which has also been shown to be suboptimal in late preterm infants compared with tern infants. Suboptimal neurobehaviour is also associated with poorer 2-year neurodevelopment in late preterm infants. More research into these tools will provide a better understanding of the underlying processes of developmental deficits of late preterm children. The value of their role in clinical care remains to be determined.

Neonatal neurological examination during the first 6h after birth

BACKGROUND

Few neurological assessments are easily performed during the first 6h after birth.

AIMS

To assess a cohort of low risk term born newborns within the first 6h and at 48h after birth using the Hammersmith Neonatal Neurological Examination.

STUDY DESIGN AND SUBJECTS

A population of low risk term born newborns was examined within 3h from birth or between 3 and 6h. Each infant was re-assessed at 48h, establishing the range and frequency distribution of neonatal neurological scores at each time point.

RESULTS

Of the 124 full-term born newborns, 62 were assessed at 0-3h and 62 at 3-6h. All infants were re-assessed at 48h. For 23/34 of the neurological items, the range and median scores were similar across the 3 time points. In the remaining 11 items the three groups had a similar range of scores but the median scores were different with different rates of changes. In 6 of the 11 the median scores at 3-6h were similar to those observed at 48h but they appeared to be 'less mature' at 0-3h. Only in one item the median scores were consistently different at the 3 time points.

CONCLUSIONS

Our results suggest that a neurological examination can already be reliably performed soon after birth. These findings will help in the interpretation of the few items that show changes with increasing postnatal age.

Neurobehaviour at term-equivalent age and neurodevelopmental outcomes at 2 years in infants born moderate-to-late preterm

AIM

To examine the association between newborn neurobehavioural assessments and neurodevelopmental outcomes at 2 years in infants born moderate-to-late preterm (MLPT).

METHOD

Two-hundred and one infants born MLPT (born 32-36⁺⁶ wks' gestation) were assessed with the Hammersmith Neonatal Neurological Examination (HNNE) and NICU Network Neurobehavioral Scale (NNNS), with suboptimal performance defined as scores lower than the 10th centile. Development was assessed at 2 years corrected age with the Bayley Scales of Infant and Toddler Development 3rd Edition, with delay defined as scores less than 1 standard deviation (SD) below the mean. The relationships between neurobehaviour at term and Bayley-III cognitive, language, and motor scales at 2 years were examined using linear regression.

RESULTS

Increased odds for cognitive delay were associated with suboptimal HNNE total scores (odds ratio [OR] 2.66; 95% confidence interval [CI] 1.14-6.23, p=0.020) and suboptimal NNNS excitability (OR 3.01; 95% CI 1.33-6.82, p=0.008) and lethargy (OR 4.05; 95% CI 1.75-9.31, p=0.001) scores. Suboptimal lethargy scores on the NNNS were associated with increased odds of language (OR 5.64; 95% CI 1.33-23.85, p=0.019) and motor delay (OR: 6.86; 95% CI 1.64-28.71, p=0.08).

INTERPRETATION

Suboptimal performance on specific aspects of newborn neurobehavioural assessments is associated with neurodevelopmental delay at 2 years in children born MLPT.

Correlation of brain ultrasonography scans to the neuromotor outcome of very-low-birth-weight infants during the first year of life

To evaluate the consistency of the Hammersmith Infant Neurological Examination scores of very-low-birth-weight infants at 6 and 12 months of age and its correlation to cranial ultrasonography findings, we designed a prospective study between January 2005 and January 2008, in the tertiary Neonatal Unit of Aristotle University of Thessaloniki, Greece. All infants enrolled had a cranial ultrasonography performed at term. Preterm infants born at <32 weeks gestation with a birth weight <1500 g were eligible for the study. One hundred seventy-four infants were finally enrolled; out of those, 46 (26%) had an optimal score at 6 and 76 (44%) at 12 months of age. Mean global scores were 61 and 69 at 6 and 12 months, respectively. The Hammersmith Infant Neurological Examination score significantly increased between 6 and 12 months, equally in all ultrasonography groups. The presence of cystic periventricular leukomalacia was associated to lower scores and neurologic impairment.

Prognostic value of the qualitative assessments of general movements in late-preterm infants

BACKGROUND

The quality of general movements (GMs) and its predictive value have never been evaluated in late-preterm (LP) infants.

AIMS

To determine the characteristics of GMs and their predictive value for neurodevelopmental outcome in a cohort of infants born between 34 and 36 weeks' gestation.

STUDY DESIGN AND SUBJECTS

574 LP infants were examined using the standard methodological principles of Prechtl's method for assessing GMs both during writhing and fidgety periods.

OUTCOME MEASURES

Infants were assessed at 2 years of age with neuromotor and developmental scales.

RESULTS

A significant correlation was found between GMs and outcome both at writhing (rs 0.68; p < 0.001) and at fidgety age (rs 0.78; p < 0.001). The assessment at 1 month showed 100% sensitivity and 86% specificity of predicting the development of cerebral palsy (CP), that at 3 months was 100% sensitivity and 97% specificity.

CONCLUSIONS

During the fidgety age GMs predict CP with very high sensitivity and specificity. The qualitative assessment of GMs should be employed to help identify LP infants who require early intervention for neurological abnormalities.

Neonatal neurological examination of late preterm babies

BACKGROUNDS

Healthy late-preterm (LP) infants examined at term equivalent age showed wider median and range of neurological scores than full-term infants; differences between infants born at 34 and those born at 35-36 weeks were also observed.

AIMS

The aim of this study is to establish the range and frequency distribution of neonatal neurological scores in a cohort of low risk LP infants assessed during the first 3 days from birth.

STUDY DESIGN AND SUBJECTS

118 low-risk infants born between 34 and 36 weeks of gestational age (GA) were assessed between 48 and 72 h from birth.

OUTCOME MEASURES

The full version of the Hammersmith Neonatal Neurologic Assessment and the screening proforma were used to assess all the infants. The raw scores obtained were compared to those of full-term infants using the same examination.

RESULTS

The distribution of neurological scores was similar among the 3 GAs for 26 items, with different median scores among LP infants born at 36 weeks and those born at 34 and 35 in only 2 items. LP infants showed a wider range of findings for each item than that of full term infants assessed soon after birth. Using the screening proforma, in our cohort, for each item the findings falling outside the 90% level were identical to those found in term-born and very preterm infants assessed at term age.

CONCLUSIONS

The neurological scores obtained in our cohort could help as reference data when examining LP infants at birth compared to age matched low risk infants.

Neurologic assessment tool for screening preterm infants at term age

The screening assessment tool of the Dubowitz neonatal neurologic assessment was adapted for preterm infants. The findings identified as "warning signs" in preterm infants were identical to those found in full-term infants, suggesting that this screening tool can also be used in preterm infants at term age.

Late preterm birth: a review of medical and neuropsychological childhood outcomes

Late preterm (LP) birth (34 0/7 - 36 6/7 weeks' gestation) accounts for nearly three-fourths of all preterm births, making this population a sizeable public health concern. The immature fetal development associated with LP delivery increases the risk of mortality and short-term medical complications. Which combination of maternal, fetal, or neonatal risk factors may be most critical has only recently begun to be addressed, and whether LP birth's disruptive impact on brain development will exert adverse effects on neuropsychological functioning in childhood and adolescence has been understudied. Early data have shown a graded response, with LP children often functioning better than very preterm children but worse than term children, and with subtle intellectual and neuropsychological deficits in LP children compared with healthy children born at term gestational age. Further characterization of the neuropsychological profile is required and would be best accomplished through prospective longitudinal studies. Moreover, since moderate and LP births result in disparate medical and psychological outcomes, the common methodology of combining these participants into a single research cohort to assess risk and outcome should be reconsidered. The rapidly growing LP outcomes literature reinforces a critical principle: fetal development occurs along a dynamic maturational continuum from conception to birth, with each successive gestational day likely to improve overall outcome.

Visual function assessment in late-preterm newborns

AIM

To describe the development of visual functions in a population of low-risk late preterm infants.

SUBJECTS AND METHODS

Eighty low-risk late preterm with a gestational age between 34.0 and 36.9 weeks were assessed at birth and at term equivalent age (TEA) using a structured visual assessment battery. The results were compared to those previously obtained in term born infants using the same battery.

RESULTS

For 5 items (spontaneous ocular motility, ocular motility with target, fixation, horizontal tracking and color tracking) the results were similar both at birth and TEA; for the other 4 (vertical and arc tracking, ability to discriminate striped black/white targets and attention at distance) visual findings at TEA were more mature than at birth. Comparing the responses in late preterm at TEA and term-born infants at 48 h of life, only 2 items (attention at distance, ability to discriminate black/white stripes) were different, with more mature findings in late preterm infants.

CONCLUSIONS

Our results show that in late preterm some aspects of visual functions have a progressive maturation infants between birth and TEA, confirming that the time between birth and term age appears to be crucial for the development of these abilities.

Neurological and visual assessments in very and late low-risk preterm infants

In this review, we report our experience on early neurological and visual developments in preterm infants assessed during the neonatal period using the Dubowitz neonatal neurological assessment and a new battery for visual assessment. The assessments were performed in both very and late low-risk preterm infants and in healthy term-born infants. We report the findings in the three cohorts, evaluating the influence of gestational age and extrauterine exposure on both neurological and visual developments.