State of the art of a new functional assessment of the young nervous system. An early predictor of cerebral palsy

Adaption of Follow-Up Visits for Preterm and High-Risk Children for Video Consultations

Introduction: Structured and standardized follow-up care for preterm and high-risk infants enables an early detection of developmental deficits. The aim is to adapt the in-person follow-up to video consultation. Developmental delays can thus be identified at an early stage, independently of in-person contact. Methods: The adaptation of these follow-up to video consultation is presented descriptively, compared with the in-person consultation (similarities, differences, challenges, and limitations). Professionals's experiences with the adaption are described. Results: The experience of n = 267 video consultations for follow-up of children up to 6 years shows that an adaptation of the in-person consultation is necessary and possible. Prerequisite is a digital medium with a stable internet connection on both sides: the professional and the family, as well as a portal for video consultations with certified, encrypted data transmission. Among infants, testing is almost entirely parent guided. For older children, testing procedures have been adapted. A neurological examination is largely possible, while a general pediatric examination is omitted. A survey on professionals' (n = 7) experiences with video- and in-person consultations found that the rate of complete follow-up visits and the resources required for taking medical histories, personnel, and time remained constant for both approaches. All reported that the video consultation is generally suitable for identifying developmental delays in children up to an age of 6 years comparable with in-person consultations. One professional stated that the physical examination of children aged ≥1 year is impossible. Discussion: Video consultation is an alternative despite some limitations when an in-person consultation is impossible. Developmental delays can be identified, and therapies recommended.

Bayley trajectories predict school readiness better than single assessments in formerly very preterm preschoolers

BACKGROUND

Development of children born very preterm (VPT) is evaluated using the Bayley Scales of Infant Development. Early Bayley scores may not predict later outcomes. We studied whether VPT Bayley trajectories in the early years predicted school readiness better than single assessments.

METHODS

We prospectively evaluated 53 VPT at 4-5 years using standardized measures of school readiness, including the domains of cognition, early mathematical and literacy abilities, and motor skills. Predictors were Bayley-III scores obtained 1-5 times/child between 6 and 35 months. Linear mixed models (LMM) with random effects extracted estimated random effect for slope (change in Bayley score/1 year) and fixed+random effect sum for the intercept (initial Bayley score) for each participant, to then evaluate 4-5-year outcomes prediction.

RESULTS

Variability of individual trajectories prevailed across developmental domains. For the initial LMM, adding Bayley change to models with only initial score improved model fits for several Bayley-III domains. Models containing estimates for initial Bayley scores and Bayley change explained significantly more variability in school readiness scores (21-63%) than either variable alone.

CONCLUSION

Neurodevelopmental follow-up of VPT is more relevant to school readiness when children are assessed multiple times in the first 3 years. Neonatal intervention research could use early trajectories rather than single timepoints as outcomes.

IMPACT

This study is the first to examine individual Bayley scores and trajectories to predict school readiness of formerly preterm children at 4-5 years. Modeling demonstrated extreme variability of individual trajectories compared to the group's average trajectories. Models containing initial Bayley scores and Bayley change over time explained more variability in preschool readiness than either variable alone. Using the Bayley to predict future school readiness is enhanced by administration across multiple follow-up visits and inclusion of change across the first 3 years. Follow-up care models and clinical trial design for neonatal interventions may benefit from a trajectory-based approach to outcomes evaluation.

Deep-Learning Markerless Tracking of Infant General Movements using Standard Video Recordings

Monitoring spontaneous General Movements (GM) of infants 6-20 weeks post-term age is a reliable tool to assess the quality of neurodevelopment in early infancy. Abnormal or absent GMs are reliable prognostic indicators of whether an infant is at risk of developing neurological impairments and disorders such as cerebral palsy (CP). Therapeutic interventions are most effective at improving neuromuscular outcomes if administered in early infancy. Current clinical protocols require trained assessors to rate videos of infant movements, a time-intensive task. This work proposes a simple, inexpensive, and broadly applicable markerless pose-estimation approach for automatic infant movement tracking using conventional video recordings from handheld devices (e.g., tablets and mobile phones). We leverage the enhanced capabilities of deep-learning technology in image processing to identify 12 anatomical locations (3 per limb) in each video frame, tracking a baby's natural movement throughout the recordings. We validate the capability of resnet152 and a mobile-net-v2-1 to identify body-parts in unseen frames from a full-term male infant, using a novel automatic unsupervised approach that fuses likelihood outputs of a Kalman filter and the deep-nets. Both deep-net models were found to perform very well in the identification of anatomical locations in the unseen data with high average Percentage of Correct Keypoints (aPCK) performances of >99.65% across all locations.Clinical relevance-Results of this research confirm the feasibility of a low-cost and publicly accessible technology to automatically track infants' GMs and diagnose those at higher risk of developing neurological conditions early, when clinical interventions are most effective.

Artificial intelligence to understand fluctuation of fetal brain activity by recognizing facial expressions

OBJECTIVE

To examine whether artificial intelligence can achieve discoveries regarding fetal brain activity.

METHODS

In this observational study, the authors collected images of fetal faces using a four-dimensional ultrasound technique obtained from singleton pregnancies of outpatients in routine practice at 27 to 37 weeks of gestation between February 1 and December 31, 2021. The authors developed an artificial intelligence classifier to recognize seven facial expressions of fetuses, then applied it to video files of fetal facial images to generate the probabilities, as confidence scores, of each expression category. Discrete Fourier transform and chaotic analysis were used to investigate the scores. Mann-Whitney test, t test, variance test, and one-way analysis of variance were used for statistical analysis.

RESULTS

Facial expression changes were observed in cycles averaging 66 to 73 s. The power spectrum showed that mouthing and neutral expressions were the most prevalent. There was a difference between categories for the spectrum (p = 0.004). Two different states--dense and sparse--of confidence scores were discovered. The correlation dimension was 1.19 ± 0.22 and 1.33 ± 0.27 for dense and sparse, respectively (p = 0.047).

CONCLUSION

This method objectively and quantitatively demonstrated fetal brain activity and may provide insight into how the fetus spends its time in utero.

A markerless pipeline to analyze spontaneous movements of preterm infants

BACKGROUND AND OBJECTIVE

The analysis of spontaneous movements of preterm infants is important because anomalous motion patterns can be a sign of neurological disorders caused by lesions in the developing brain. A diagnosis in the first weeks of child's life is crucial to plan timely and appropriate rehabilitative interventions. An accurate visual assessment of infants' spontaneous movements requires highly specialized personnel, not always available, and it is operator dependent. Motion capture systems, markers and wearable sensors are commonly used for human motion analysis, but they can be cumbersome, limiting their use in the study of infants' movements.

METHODS

In this paper we propose a computer-aided pipeline to characterize and classify infants' motion from 2D video recordings. The final goal is detecting anomalous motion patterns. The implemented pipeline is based on computer vision and machine learning algorithms and includes a specific step to increase the interpretability of the results. Specifically, it can be summarized by the following steps: (i) body keypoints detection: we rely on a deep learning-based semantic features detector to localize the positions of meaningful landmark points on infants' bodies; (ii) parameters extraction: starting from the trajectories of the detected landmark points, we extract quantitative parameters describing infants motion patterns; (iii) classification: we implement different classifiers (Support Vector Machines, Random Forest, fully connected Neural Network, Long Short Term Memory) that, starting from the motion parameters, classify between normal or abnormal motion patterns.

RESULTS

We tested the proposed pipeline on a dataset, recorded at the 40th gestational week, of 142 infants, 59 with evidence of neuromotor disorders according to a medical assessment carried out a posteriori. Our procedure successfully discriminates normal and anomalous motion patterns with a maximum accuracy of 85.7%.

CONCLUSIONS

In conclusion, our pipeline has the potential to be adopted as a tool to support the early detection of abnormal motion patterns in preterm infants.

Association between General Movements Assessment and Later Motor Delay (excluding Cerebral Palsy) in Low-Birth-Weight Infants

The general movements (GMs) assessment is useful for the prediction of cerebral palsy (CP) and other developmental disorders. Developmental coordination disorder (DCD) is highly prevalent in low-birth-weight (LBW) infants. We investigated the association between aberrant GMs during early infancy and later motor development in LBW infants. The study included infants who fulfilled the following criteria: GMs assessed at 9–20 weeks post-term age; developmental quotient (DQ) assessed at 3 years of age using the Kyoto Scale; intelligence quotient (IQ) assessed at 6 years of age. Participants with normal IQs at 6 years of age without a diagnosis of CP (14 males and 37 females, 23–36 weeks gestation with birth weights of 492–1498 g) were categorized into normal (n = 39) and aberrant (n = 12) groups based on GMs assessment; DQ was compared between the groups. We investigated the items in the DQ assessment and found that the infants in the aberrant group were more frequently unable to perform. Infants in the aberrant group showed a significantly lower DQ in the ‘postural-motor domain’, and were more frequently unable to ‘climb the stairs with alternating legs’ and ‘Jump from a 15–20 cm platform’. This study highlights that GMs aberrancy in early infancy is associated with a delayed gross motor development, even in children with a typical development. The GMs assessment may be useful for the prediction of DCD.

Anticipatory regulation of cardiovascular system on the emergence of auditory-motor interaction in young infants

Humans develop auditory-motor interaction to produce a variety of rhythmic sounds using body movements, which are often produced and amplified with tools, such as drumming. The extended production of sounds allows us to express a wide range of emotions, accompanied by physiological changes. According to previous studies, even young infants enhance movements in response to auditory feedback. However, their exhibition of physiological adaptation on the emergence of auditory-motor interaction is unclear. We investigated the movement and cardiac changes associated with auditory feedback to spontaneous limb movements in 3-month-old infants. The results showed that infants increased the frequency of limb movements inducing auditory feedback, while they exhibited a more regular rhythm of the limb movements. Furthermore, heart rate increase associated with the limb movement was first inhibited immediately after the timing of the auditory feedback, which may reflect sustained attention to the auditory stimuli. Then, through auditory-motor experience, the heart rate increase was inhibited even prior to the auditory feedback, leading to suppression of the peak intensity of the heart rate increase. These findings suggest that young infants regulate the cardiovascular system as well as limb movements in anticipation of the auditory feedback. The anticipatory regulation associated with movement and attentional changes may contribute to reduced cardiovascular stress in auditory-motor interaction, and provide a developmental basis for more sophisticated goal-directed behavior of producing rhythmic sounds.

Deep learning-based quantitative analyses of spontaneous movements and their association with early neurological development in preterm infants

This study aimed to develop quantitative assessments of spontaneous movements in high-risk preterm infants based on a deep learning algorithm. Video images of spontaneous movements were recorded in very preterm infants at the term-equivalent age. The Hammersmith Infant Neurological Examination (HINE) was performed in infants at 4 months of corrected age. Joint positional data were extracted using a pretrained pose-estimation model. Complexity and similarity indices of joint angle and angular velocity in terms of sample entropy and Pearson correlation coefficient were compared between the infants with HINE < 60 and ≥ 60. Video images of spontaneous movements were recorded in 65 preterm infants at term-equivalent age. Complexity indices of joint angles and angular velocities differed between the infants with HINE < 60 and ≥ 60 and correlated positively with HINE scores in most of the joints at the upper and lower extremities (p < 0.05). Similarity indices between each joint angle or joint angular velocity did not differ between the two groups in most of the joints at the upper and lower extremities. Quantitative assessments of spontaneous movements in preterm infants are feasible using a deep learning algorithm and sample entropy. The results indicated that complexity indices of joint movements at both the upper and lower extremities can be potential candidates for detecting developmental outcomes in preterm infants.

Early detection relationship of cerebral palsy markers using brain structure and general movements in infants born <32 weeks gestational age

AIM

To detect early brain structural and clinical functional markers of brain injury and development based on a magnetic resonance imaging (MRI) scoring system and a general movement assessment (GMA) for preterm infants later diagnosed with cerebral palsy (CP).

STUDY DESIGN

Retrospective cohort study. General movements (GMs) were scored according to a semiquantitative scoring system: the GMs optimality score (GMOS) at preterm and term ages and the Motor Optimality Score (MOS) at the corrected age of 3 months after birth. Brain magnetic resonance imaging (MRI) at term-equivalent age was scored using an MRI scoring system. We analyzed the relationship between the early degree of cerebral white matter (WM) abnormality and the GMOS and the MOS for infants born <32 weeks gestational age later diagnosed with CP in a comparison group of neurotypical controls.

SUBJECTS

Sixteen preterm infants were included in this study who underwent MRI and GMs assessment. 8 out of the 16 preterm infants were later diagnosed with CP, while the other 8 infants with normal motor development (N) were placed into the control group. Their median gestational age was 30w6d and 27w6d for each group respectively.

RESULTS

The cerebral WM MRI scores were significantly higher in the CP group than in the control group (p < 0.01). The GMOS and MOS were significantly higher in the control group than in the CP group (p < 0.05). The MOS showed a strong correlation to the cerebral WM MRI score (r = -0.88) and the subscale of cerebral WM items (the cystic degeneration and the focal signal abnormalities) of the MRI score (r = -0.94) in the CP group. The MOS also showed a correlation with corrected biparietal diameter (cBPD) in the preterm infant group with CP (r = 0.75). Results of linear regression analyses between term MRI and GMs measures in preterm infants with CP are presented. Cerebral WM scores were associated with the MOS (β = -0.63; 95%CI = -0.97, -0.29; p < 0.01). Cerebral WM injury, including the subscale of cystic degeneration and focal signal abnormalities was closely associated with the MOS (β = -0.83; 95%CI = -1.13, -0.54; p < 0.001).

CONCLUSION

Cerebral WM scores show a strong association with a decreased motor performance on the MOS in preterm infants later diagnosed with CP. Severe white matter injury and significantly decreased MOS scores may provide useful early markers and strong evidence to early predict the risk of later development of cerebral palsy in preterm infants.

Infant's Behaviour Checklist for low birth weight infants and later neurodevelopmental outcome

Assessment of the characteristics of spontaneous movements and behaviour in early infancy helps in estimating developmental outcomes. We introduced the Infant Behaviour Checklist (IBC) and examined the relationship between the behavioural characteristics of low-birth-weight infants and neurodevelopmental outcomes at 6 years of age. The behavioural characteristics during the neonatal (36-43 weeks, adjusted) and early infancy periods (49-60 weeks, adjusted) were assessed in very-low-birth-weight infants. The IBC includes 44 common behaviours. We assessed the appearance of individual behavioural characteristics at each period according to the neurodevelopmental outcome. Of the 143 infants assessed during the neonatal period, 89 had typical development (TD), 30 had intellectual disability (ID), and 24 had autism spectrum disorder (ASD). In 78 infants assessed during early infancy, 40, 21, and 17 had TD, ID, and ASD, respectively. The frequency of appearance of three behaviour-related items was significantly lower in the ID group than in the TD group. The frequency of appearance of three posture- and behaviour-related items was significantly lower, while that of two posture-related items was significantly higher, in the ASD group than in the TD group. Behavioural assessment using the IBC may provide promising clues when considering early intervention for low-birth-weight infants.

Very Preterm Early Motor Repertoire and Neurodevelopmental Outcomes at 8 Years

BACKGROUND AND OBJECTIVES

Children born very preterm (<32 weeks' gestation) have more neurodevelopmental problems compared with term-born peers. Aberrant fidgety movements (FMs) are associated with adverse motor outcomes in children born very preterm. However, associations of aberrant FMs combined with additional movements and postures to give a motor optimality score-revised (MOS-R) with school-aged cognitive and motor outcomes are unclear. Our aim with this study was to determine those associations.

METHODS

Of 118 infants born <30 weeks' gestation recruited into a randomized controlled trial of early intervention, 97 had a general movements assessment at 3 months' corrected age and were eligible for this study. Early motor repertoire including FMs and MOS-R were scored from videos of infant's spontaneous movement at 3 months' corrected age. At 8 years' corrected age, cognitive and motor performances were evaluated. Associations of early FMs and MOS-R with outcomes at 8 years were determined using linear regression.

RESULTS

Seventy-eight (80%) infants with early motor repertoire data had neurodevelopmental assessments at 8 years. A higher MOS-R, and favorable components of the individual subscales of the MOS-R, including the presence of normal FMs, were associated with better performance for general cognition, attention, working memory, executive function and motor function at 8 years; eg, presence of normal FMs was associated with a 21.6 points higher general conceptual ability score (95% confidence interval: 12.8-30.5; P < .001) compared with absent FMs.

CONCLUSIONS

Favorable early motor repertoire of infants born <30 weeks is strongly associated with improved cognitive and motor performance at 8 years.

Recognition of facial expression of fetuses by artificial intelligence (AI)

OBJECTIVES

The development of the artificial intelligence (AI) classifier to recognize fetal facial expressions that are considered as being related to the brain development of fetuses as a retrospective, non-interventional pilot study.

METHODS

Images of fetal faces with sonography obtained from outpatient pregnant women with a singleton fetus were enrolled in routine conventional practice from 19 to 38 weeks of gestation from January 1, 2020, to September 30, 2020, with completely de-identified data. The images were classified into seven categories, such as eye blinking, mouthing, face without any expression, scowling, smiling, tongue expulsion, and yawning. The category in which the number of fetuses was less than 10 was eliminated before preparation. Next, we created a deep learning AI classifier with the data. Statistical values such as accuracy for the test dataset and the AI confidence score profiles for each category per image for all data were obtained.

RESULTS

The number of fetuses/images in the rated categories were 14/147, 23/302, 33/320, 8/55, and 10/72 for eye blinking, mouthing, face without any expression, scowling, and yawning, respectively. The accuracy of the AI fetal facial expression for the entire test data set was 0.985. The accuracy/sensitivity/specificity values were 0.996/0.993/1.000, 0.992/0.986/1.000, 0.985/1.000/0.979, 0.996/0.888/1.000, and 1.000/1.000/1.000 for the eye blinking, mouthing, face without any expression, scowling categories, and yawning, respectively.

CONCLUSIONS

The AI classifier has the potential to objectively classify fetal facial expressions. AI can advance fetal brain development research using ultrasound.

Transient structural MRI patterns correlate with the motor functions in preterm infants

AIM

To explore the relationships between transient structural brain patterns on MRI at preterm and at term-equivalent age (TEA) as a predictor of general movements (GMs) and motor development at 1-year corrected age (CA) in very preterm infants.

METHODS

In this prospective study, 30 very preterm infants (median = 28wks; 16 males) had structural magnetic resonance imaging (MRI) at preterm (median = 31wks + 6d) and at TEA (median = 40wks) and neuromotor assessments. The quality of GMs was assessed by Prechtl's general movements assessment and a detailed analysis of the motor repertoire was performed by calculating a motor optimality score (MOS), both at term age and at 3 months post-term. Motor development at 1-year CA was evaluated with the Infant Motor Profile (IMP). Associations between qualitative MRI findings and neuromotor scores were investigated.

RESULTS

Abnormal GMs and low motor performance at 1-year CA were associated with the poor visibility of transient structural pattern, that is with sagittal strata.

INTERPRETATION

Transient structural MRI pattern, sagittal strata, at preterm age is related to the quality of GMs and later motor development in preterm infants. This transient fetal brain compartment may be considered as a component of neurobiological basis for early neuromotor behavior, as expressed by GMs.

Spatial, But Not Temporal, Kinematics of Spontaneous Upper Extremity Movements Are Related to Gross and Fine Motor Skill Attainment in Infancy

Background: Spontaneous upper extremity movements in infancy provide insight on neuromotor development. Spatiotemporal kinematics have been used to evaluate typical development of reaching, a foundational motor skill in infancy. This study evaluates the relationship between spontaneous upper extremity movements, not elicited by a toy, and motor skill attainment. Methods: N = 12 healthy infants (2–8 months) participated in this longitudinal study (one to four sessions). Motor skills were assessed with the Bayley Scales of Infant and Toddler Development, 3rd Edition: gross motor subtest (GM) and fine motor subtest. Spontaneous upper extremity movements were collected using 3D motion capture technology. Infants were placed in supine for three to twelve 30-s trials, and their movements were recorded. Repeated measure correlation coefficients (Rmcorr) were used to evaluate relationships between variables. Results: There were significant, moderate, positive relationships between the straight distance from start to end of a movement and (a) fine motor score (Rmcorr = .55, p = .03), (b) GM score (Rmcorr = .63, p = .01), and (c) age (Rmcorr = .56, p = .02). There was a significant, moderate, negative relationship between straightness ratio and GM score (Rmcorr = −.52, p = .047). Discussion: Fine and GM skills are related to the straight distance from start to end of a movement and the straightness ratio of underlying spontaneous upper extremity movements.

General Movement Assessment Predicts Neuro-Developmental Outcome in Very Low Birth Weight Infants at Two Years - A Five-Year Observational Study

OBJECTIVE

To assess the value of general movements (GMs) in predicting the neurodevelopmental outcome using Bayley Scale of Infant Development III (BSID-III) at two years of age in very low birth weight (VLBW) infants.

METHODS

This is a five-year observational study (January 2012-June 2017). Two hundred twenty-seven VLBW infants were assessed in the neurodevelopmental clinic between Jan 2012 and June 2017. Of these 137 infants had GMs assessments at 3 mo post term (first visit to the clinic).

RESULTS

Absence of fidgety movements (FMs) at 3 mo post term had high specificity and negative predictive value for moderate to severe neurodevelopmental outcome in motor, cognition and language domains (composite score less than 70 in the Bayley III scales of Infant development scores). At 3 mo post term, absent FMs had high sensitivity, specificity and negative predictive value (NPV) for cerebral palsy (CP).

CONCLUSIONS

GMs assessment at 3 mo post term could be considered as an important screening tool for early identification of VLBW infants who are at risk of neurodevelopmental impairment/cerebral palsy.

Longitudinal assessment of U-shaped and inverted U-shaped developmental changes in the spontaneous movements of infants via markerless video analysis

Various attempts have been made to elucidate the development patterns in the spontaneous movements of infants through longitudinal evaluations. Movement complexity has been found to demonstrate u-shaped changes in the measurements focusing on limb movements. However, researchers have not yet clarified how other characteristics, besides movement complexity, change over time. This paper presents a longitudinal evaluation of spontaneous movements in infants using evaluation indices calculated through markerless video analysis. Nine infants with corrected ages from \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$-1$$\end{document}-1 to 15 weeks participated in the experiments. We confirmed the change in indices over time using statistical methods. Index changes can be classified as positively correlated, u-shaped, inverted u-shaped, and uncorrelated. We also confirmed that the u-shaped and inverted u-shaped indices are negatively correlated. Furthermore, the principal component analysis revealed that the first principal component had the inverted u-shaped changes with the corrected age. These results suggest that it is important to synchronize the inverted u-shaped variations in the movement and velocity with the u-shaped changes in the movement complexity for infant development.

Using network analysis to capture developmental change: An illustration from infants' postural transitions

Network analysis is a tool typically used to assess interrelationships between social entities in a system. In this methodological report, we introduce how concepts from network analysis can be utilized to capture, condense, and extract complex developmental changes in individual behaviors over time. Using infant postural-locomotor development as an example, we demonstrate how network analysis principles can be applied to rich empirical data. We used existing free-play data from 13 infants followed longitudinally as they progressed from sitting to walking. We documented the range of postures adopted during play, how often infants transitioned between postures in their postural networks, and derived parameters of density and centrality. Analysis revealed that posture network density increased after infants learned to crawl and gained crawling experience as one might expect, but density did not further expand with gains in upright locomotion. Certain postures held different roles in the overall posture network displayed by an infant, and these centrality patterns depended on the time period involved. More central postures in the network were not always postures in which infants spent the most time. We discuss how network analysis might be utilized to better understand infant behaviors in other contexts (e.g., problem-solving, interventions, humanoid robotics).

Toward Predicting Infant Developmental Outcomes From Day-Long Inertial Motion Recordings

As improvements in medicine lower infant mortality rates, more infants with neuromotor challenges survive past birth. The motor, social, and cognitive development of these infants are closely interrelated, and challenges in any of these areas can lead to developmental differences. Thus, analyzing one of these domains - the motion of young infants - can yield insights on developmental progress to help identify individuals who would benefit most from early interventions. In the presented data collection, we gathered day-long inertial motion recordings from N = 12 typically developing (TD) infants and N = 24 infants who were classified as at risk for developmental delays (AR) due to complications at or before birth. As a first research step, we used simple machine learning methods (decision trees, k-nearest neighbors, and support vector machines) to classify infants as TD or AR based on their movement recordings and demographic data. Our next aim was to predict future outcomes for the AR infants using the same simple classifiers trained from the same movement recordings and demographic data. We achieved a 94.4% overall accuracy in classifying infants as TD or AR, and an 89.5% overall accuracy predicting future outcomes for the AR infants. The addition of inertial data was much more important to producing accurate future predictions than identification of current status. This work is an important step toward helping stakeholders to monitor the developmental progress of AR infants and identify infants who may be at the greatest risk for ongoing developmental challenges.

Video-based evaluation of infant crawling toward quantitative assessment of motor development

This study proposes a quantitative evaluation support system for infant motor development and uses the system to analyze hands-and-knees creeping and belly crawling. This system measures movements using two video cameras and extracts movement features via background and inter-frame subtractions of original images. Eight evaluation indices for each crawling cycle are calculated, enabling markerless movement analysis of infants. Cross-sectional analysis of 16 10-month-olds confirmed significant differences between hands-and-knees creeping and belly crawling in five of the eight indices, demonstrating the system capability to quantitatively differentiate between creeping and crawling. Longitudinal analysis of one infant (aged 7–10 months) also suggested that the proposed quantitative indices can follow changes in crawling characteristics and evaluate infants’ motor development process. The results from the experiments suggest that the proposed system may enable diagnosis support in clinical practice.

Infants Show Physiological Responses Specific to Parental Hugs

Caregivers hug their infants to express affection and joy. However, it remains unknown how infants react to being hugged. Here we examined heart rate responses in first-year infants during a hug, hold, and tight hug from parents. Infants older than four months showed an increased R-R interval (RRI) during a hug, indicating reduced heart rates and pronounced parasympathetic activity. Few head movements predicted a higher RRI increase in infants during a parental hug compared with that during a hold and tight hug. Infants did not show an increased RRI during a hug from a female stranger. Infants younger than four months did not show RRI increase during parental hug but exhibited a decreased RRI correlated with contact pressure. Parents showed an increased RRI during hugging their infants. These results suggest the parent-infant hug underlies the parent-infant bonding and psychophysiological development of infants.

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We examined heart rate responses in first-year infants during hugs from parents

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Infants showed an RRI increase when hugged by parents but not by strangers

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Few head movements predicted higher RRI increase during a parental hug

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Parents also showed an increased RRI when hugging their infants

Markerless Measurement and Evaluation of General Movements in Infants

General movements (GMs), a type of spontaneous movement, have been used for the early diagnosis of infant disorders. In clinical practice, GMs are visually assessed by qualified licensees; however, this presents a difficulty in terms of quantitative evaluation. Various measurement systems for the quantitative evaluation of GMs track target markers attached to infants; however, these markers may disturb infants’ spontaneous movements. This paper proposes a markerless movement measurement and evaluation system for GMs in infants. The proposed system calculates 25 indices related to GMs, including the magnitude and rhythm of movements, by video analysis, that is, by calculating background subtractions and frame differences. Movement classification is performed based on the clinical definition of GMs by using an artificial neural network with a stochastic structure. This supports the assessment of GMs and early diagnoses of disabilities in infants. In a series of experiments, the proposed system is applied to movement evaluation and classification in full-term infants and low-birth-weight infants. The experimental results confirm that the average agreement between four GMs classified by the proposed system and those identified by a licensee reaches up to 83.1 ± 1.84%. In addition, the classification accuracy of normal and abnormal movements reaches 90.2 ± 0.94%.

Validity of General Movement Assessment Based on Clinical and Home Videos

INTRODUCTION

The purposes of this study were to develop an instructional leaflet on home video recording for the General Movement Assessment (GMA) and to examine the concurrent and predictive validity of the GMA completed by physical therapists (PTs) and completed by parents.

METHODS

The GMA and the Alberta Infant Motor Scale (AIMS) were completed by PTs in the clinic. Parents completed the GMA following the instructional leaflet.

RESULTS

The content validity of the leaflet was 0.83. The consistency of the GMA results between sources was κ = 0.869. The concurrent validity of the GMA at a corrected age of 3 months was κ = 0.266 (PT) versus 0.525 (parent) using the 10th-percentile cutoffs of the AIMS. The positive likelihood ratio was 26 (PT) versus 25 (parents) at a corrected age of 12 months based on 5th-percentile cutoffs of the AIMS.

CONCLUSIONS

Home GMA videos are valid for clinical assessment following the instructional leaflet.

Twin fetal facial expressions at 30-33+6 weeks of gestation

Objective To assess the characteristics of twin fetal facial expressions at 30-33 + 6 weeks of gestation using four-dimensional (4D) ultrasound to clarify twin fetal brain development and maturation. Methods Frequencies of seven fetal facial expressions were studied using 4D ultrasound for 15 minutes in 30 singleton pregnancies and 18 twin pregnancies [four monochorionic diamniotic (MD) and 14 dichorionic diamniotic (DD) twins] at 30-33 + 6 weeks of gestation. Comparison of the frequency in each facial expression was performed between singleton and twin fetuses. Results Mouthing was the most frequent facial expression at 30-33 + 6 weeks of gestation, followed by blinking in twin and singleton fetuses. Both facial expressions were significantly more frequent than other expressions (P < 0.05). The frequencies of mouthing and scowling in twin fetuses were significantly lower than those in singleton fetuses, but there were no significant differences in the frequencies of the five other facial expressions between the fetal groups. Conclusion Our results suggest that restricted twin fetal behavior before 20 weeks of gestation may still affect the frequencies of twin facial expressions early in the third trimester of pregnancy. Moreover, the frequencies of facial expressions in twins are different from those of singleton fetuses.

The shape of disposable diaper affects spontaneous movements of lower limbs in young infants

This study examined the characteristics of young infants' lower limb spontaneous movements based on differences in shape of diapers. Twenty-seven healthy infants (103 ± 16.3 days old) were enrolled in this study. We measured the spontaneous movements of their lower limbs in four conditions (Naked, wearing Normal type diapers, wearing Type A diapers, and wearing Type B diapers). The Normal diaper has a wider waist belt than the Type A diaper, and the Type B diaper has a narrower crotch area than the Type A diaper. We observed them in seven indices (the velocity of lower limb movements, the trajectory area of knee movement in the sagittal plane and the frontal plane, the distance between both knees and between side of abdomen and knee, and correlation of velocities between side of abdomen and knee and between left and right ankles). The results showed that the velocity of the lower limb movements in the Naked condition was higher than when wearing Normal diapers. The value for the trajectory area of knee movement in sagittal plane, which reflects the range of lower leg lifting movements and closeness of such movements to the trunk, for the Type B diaper condition was higher than that for the Normal diaper condition. This result indicates that the shape of the diaper affects the spontaneous movements of the lower limbs of young infants.

A novel two-body sensor system to study spontaneous movements in infants during caregiver physical contact

Spontaneous movements, which refer to repetitive limb movements in the absence of any external stimulus, have been found to be reflective of neurodevelopmental status during infancy. These movements are modulated by both individual and environmental factors, including physical contact (holding) with the caregiver. However, it is a challenge to measure spontaneous movements during physical contact because infant-generated movements become coupled with caregiver-generated movements in such contexts. Here, we propose the use of a novel two-body sensor system to distinguish infant-generated movements in the presence of physical contact with the caregiver. Data from seven typically developing infants and their caregivers were recorded during different simulated home activities, which involved different combinations of physical interaction, caregiver's movement and infant positions. The two-body sensor system consisted of two wearable accelerometers - one placed on the infant's arm and one on the caregiver's arm, and we developed a Kalman-filter based algorithm to isolate the infant-generated movements. In addition, video was recorded for qualitative analysis. Results indicated that spontaneous movement activity was higher when there was no physical contact with caregiver. When there was physical contact, spontaneous movements were increased when the caregiver was still and when the infant was held horizontally. These results show that the novel two-body sensor system and the associated algorithms were able to isolate infant-generated movements during physical contact with the caregiver. This approach holds promise for the automated long-term tracking of spontaneous movements in infants, which may provide critical insight into developmental disorders.

Evaluation of Fidgety Movements of Infants Based on Gestalt Perception Reflects Differences in Limb Movement Trajectory Curvature

BACKGROUND

Infants aged 2 to 5 months show spontaneous general movements (GMs) of the whole body, which are referred to as fidgety movements (FMs). Although previous studies have shown that evaluation of GMs by the General Movement Assessment (GMA) has predictive value about later neurological impairments, it remains unknown whether raters consistently perceive and rate such complex kinematic information.

OBJECTIVE

The purpose of this study was to construct a method to reveal which movement features are associated with each rater's evaluation of FMs based on the GMA.

DESIGN

GMA scores of 163 healthy infants aged 11 to 16 weeks postterm were matched with data obtained from a 3-dimensional motion analysis system.

METHODS

Three physical therapists performed the GMA and classified GMs into 9 types, from which we focused on 3 subtypes differing in the temporal organization of FMs (continual, intermittent, and sporadic FMs). We also calculated 6 movement indices (average velocity of limb movements, number of movement units, kurtosis of acceleration, jerk index, average curvature, and correlation between limb velocities) for arms and legs for each infant and analyzed which movement indices were associated with the ratings of the 3 FM subtypes by each rater.

RESULTS

Only the average curvature differed significantly among the ratings of the 3 FM subtypes for all 3 raters. Each rater showed significant differences in the average curvature in either arms or legs.

LIMITATIONS

It is difficult to generalize the present results to raters with various levels of expertise and experience in using the GMA. This issue calls for further research.

CONCLUSIONS

The method used revealed commonality and individuality about the perceived movement features that can be associated with the rating of FMs.

Early motor and pre-linguistic verbal development in Prader-Willi syndrome - A case report

BACKGROUND

Prader-Willi syndrome (PWS) is a rare genetic disorder. Infants with PWS show a neurodevelopmental dysfunction which entails a delayed motor and language development, but studies on their spontaneous movements (i.e. general movements) or pre-linguistic speech-language development before 6 months of age are missing so far.

AIM

To describe early motor and pre-linguistic verbal development in an infant with PWS.

METHODS AND PROCEDURES

Prospective case report; in addition to the assessment of general movements and the concurrent movement repertoire, we report on early verbal forms, applying the Stark Assessment of Early Vocal Development-Revised.

OUTCOMES AND RESULTS

General movements were abnormal on days 8 and 15. No fidgety movements were observed at 11 weeks; they only emerged at 17 weeks and lasted until at least 27 weeks post-term. The movement character was monotonous, and early motor milestones were only achieved with a delay. At 27 weeks the infant produced age-adequate types of vocalisations. However, none of the canonical-syllable vocalisations that typically emerge at that age were observed. Early vocalisations appeared monotonous and with a peculiarly harmonic structure.

CONCLUSIONS AND IMPLICATIONS

Early motor and pre-linguistic verbal behaviours were monotonous in an infant with PWS throughout his first 6 months of life. This suggests that early signs of neurodevelopmental dysfunction (i.e. abnormal general movements) might already be diagnosed in infants with PWS during their first weeks of life, potentially enabling us to diagnose and intervene at an early stage.

The acute effects of physiotherapy on general movement patterns in preterm infants: A single-blind study

BACKGROUND

The General Movement Assessment (GMA) is a video analysis method developed by Heinz Prechtl that examines the infant's spontaneous movements. In recent years, although many studies have been performed in preterm infants by applying GMA, few studies have shown the effects of early intervention on GMA.

AIMS

Current study was planned to determine the acute effects of a single-session early physiotherapy approach on preterm infants' general spontaneous movements, and to reveal the change in Motor Optimality Scale (MOS) score including FMs.

STUDY DESIGN

Prospective, single-blind study.

SUBJECTS

Current study was carried out with 32 preterm infants at postterm 12-16 weeks.

OUTCOME MEASURES

The infants included in the study were videotaped by a physiotherapist during 10-15 min before the physiotherapy session at postterm 12-16 weeks for GMA. After a single physiotherapy session, the same physiotherapist performed the same video footage second time. A blind evaluator assessed the videos taken before and after session and scored Motor Optimality Scale (MOS).

RESULTS AND CONCLUSIONS

There was no statistically significant difference between MOS sub-category and total score of the infants before and after the session (p > 0.05). According to the results of present study, a single-session early physiotherapy intervention did not have an acute effect on the spontaneous movements of preterm infants at postterm 12-16 weeks. Future studies are needed to demonstrate the short and long-term effects of early physiotherapy approaches to risky infants.

Differences in Spontaneous Leg Movement Patterns Between Infants With Typical Development and Infants at Risk for Developmental Delay: Cross-sectional Observation Prior to Sitting Onset

Purpose

To investigate differences in the patterns of supine spontaneous leg movements produced before sitting onset between infants with typical development (TD) and infants at risk for developmental delay (AR).

Method

Cross-sectional, observational study. Thirty-five infants were included, 18 infants with TD (130.4 ±38.0 days) and 17 infants AR (124.1± 65.7 days). Infants were placed in the supine position and video taped for 4 to 5 minutes while in an alert, content state. After the recording, videos were coded frame by frame to identify the type of each leg movement produced: single flexion, single extension, alternate flexion, alternate extension, parallel flexion, parallel extension, leg wave, leg circle, leg thump, foot rub, foot flexion, or foot rotation.

Results

Unilateral movements (single flexion and single extension) were the most common leg movements in TD group. Infants AR produced a significantly lower proportion of unilateral and foot rub movements than infants with TD.

Conclusion

These results provide a foundation of the types of leg movement pattern differences to build on in future research. Knowledge about differences in spontaneous movement patterns between infants AR and infants with TD has relevance both for early identification of neuromotor impairment and clinical practice.

Spontaneous movements in the first four months of life: An accelerometric study in moderate and late preterm infants

BACKGROUND

Moderate preterm infants (MPI) and late preterm infants (LPI) account for the majority of children born preterm. Up to 5% of MPI and LPI are estimated to manifest neurodevelopmental impairments. However, information about normal early motor development in these patients is lacking.

AIM

To find characteristic patterns for motor development in the first four months of life among MPI and LPI without risk factors for developmental impairment by using accelerometry of spontaneous movements.

STUDY DESIGN

Prospective and observational study.

SUBJECTS

Twenty-three MPI and LPI (9 female, 14 male) without known risk factors for neurodevelopmental impairment were included in this study. Spontaneous movements were measured by accelerometry at the time of hospital discharge (mean: 36.6wks postmenstrual age (PMA)) and at the corrected age of three months (mean: 53.0wks PMA).

OUTCOME MEASURES

Motor development was described by analyzing 36 parameters calculated from the acceleration signal. Normal neurodevelopmental outcome was confirmed by Bayley Scales of Infant Development at the corrected age of two years.

RESULTS

Statistically significant differences (p < 0.05) between the two measurements could be shown in 26 out of the 36 parameters. Striking changes in motor development were an increase in acceleration and variability of the spontaneous movements, the main criterion for analyzing spontaneous movements. Furthermore, the regularity of spontaneous movements increased significantly.

CONCLUSION

Characteristic patterns of normal motor development in MPI and LPI can be identified and provide a basis for future investigations aiming at the early detection of abnormal motor development for this specific patient group.

Identification of Developmental Delay in Infants Using Wearable Sensors: Full-Day Leg Movement Statistical Feature Analysis

This paper examines how features extracted from full-day data recorded by wearable sensors are able to differentiate between infants with typical development and those with or at risk for developmental delays. Wearable sensors were used to collect full-day (8-13 h) leg movement data from infants with typical development ([Formula: see text]) and infants at risk for developmental delay ([Formula: see text]). At 24 months, at-risk infants were assessed as having good ([Formula: see text]) or poor ([Formula: see text]) developmental outcomes. With this limited size dataset, our statistical analysis indicated that accelerometer features collected earlier in infancy differentiated between at-risk infants with poor and good outcomes at 24 months, as well as infants with typical development. This paper also tested how these features performed on a subset of the data for which the infant movement was known, i.e., 5-min intervals more representative of clinical observations. Our results on this limited dataset indicated that features for full-day data showed more group differences than similar features for the 5-min intervals, supporting the usefulness of full-day movement monitoring.

A Ballistographic Approach for Continuous and Non-Obtrusive Monitoring of Movement in Neonates

Continuously monitoring body movement in preterm infants can have important clinical applications since changes in movement-patterns can be a significant marker for clinical deteriorations including the onset of sepsis, seizures, and apneas. This paper proposes a system and method to monitor body movement of preterm infants in a clinical environment using ballistography. The ballistographic signal (BSG) is acquired using a thin and a film-like sensor that is placed underneath an infant. Manual annotations based on video-recordings served as a reference standard for identifying movement. We investigated the performance of multiple features, constructed from the BSG waveform, to discriminate movement from no movement based on data acquired from 10 preterm infants. Since routine cardiorespiratory monitoring is prone to movement artifacts, we also compared the application of these features on the simultaneously acquired cardiorespiratory waveforms, i.e., the electrocardiogram, the chest impedance, and the photoplethysmogram. The BSG-based-features consistently outperformed those based on the routinely acquired cardiorespiratory waveforms. The best performing BSG-based feature-the signal instability index-had a mean (standard deviation) effect size of 0.90 (0.06), as measured by the area under the receiver operating curve. The proposed system for monitoring body movement is robust to noise, non-obtrusive, and has high performance in clinical settings.

Telling Apart Motor Noise and Exploratory Behavior, in Early Development

Infants' minutes long babbling bouts or repetitive reaching for or mouthing of whatever they can get their hands on gives very much the impression of active exploration, a building block for early learning. But how can we tell apart active exploration from the activity of an immature motor system, attempting but failing to achieve goal directed behavior? I will focus here on evidence that infants increase motor activity and variability when faced with opportunities to gather new information (about their own bodies or the world) and propose this as a guiding principle for separating variability generated for exploration from noise. I will discuss mechanisms generating movement variability, and suggests that, in the various forms it takes, from deliberate hypothesis testing to increasing environmental variability, it could be exploited for learning. However, understanding how variability in motor acts contributes to early learning will require more in-depth investigations of both the nature of and the contextual modulation of this variability.

Spontaneous movements of preterm infants is associated with outcome of gross motor development

AIMS

We conducted a longitudinal cohort study to analyze the relationship between outcome of gross motor development in preterm infants and factors that might affect their development.

METHODS

Preterm infants with a birth weight of <1500 g were recruited. We measured spontaneous antigravity limbs movements by 3D motion capture system at 3 months corrected age. Gross motor developmental outcomes at 6 and 12 months corrected age were evaluated using the Alberta Infant Motor Scale (AIMS). Statistical analysis was carried out by canonical correlation analysis.

RESULTS

Eighteen preterm infants were included. In the 6 months corrected age analysis, spontaneous movement had a major effect on Prone and Sitting at 6 months corrected age of AIMS. In the 12 months corrected age analysis, spontaneous movement had a major effect on Sitting and Standing at 12 months corrected age of AIMS.

CONCLUSIONS

In preterm infants, better antigravity spontaneous movements at 3 months corrected age were significantly correlated with better gross motor development at 6 or 12 months corrected age.

[Application of movement recognition technology in assessing spontaneous general movements in preterm infants]

Preterm birth is a major factor which induces neurological and motor impairments, particularly cerebral palsy, in high-risk infants. Early identification of potential neurodevelopmental impairments provides the opportunity to improve neurodevelopmental outcomes in preterm infants through early rehabilitation interventions. Clinically, the general movement assessment is a pivotal tool to predict neurodevelopmental outcomes, especially motor developmental outcomes, in high-risk infants. Movement recognition can continuously capture relevant limb movements and perform objective and quantitative assessment using computerized approaches. Various methods of recording and analyzing spontaneous general movements for infants at a risk of cerebral palsy have been extensively explored. This article summarizes the general movement assessment method and reviews the translational research on using movement recognition technology for the assessment of spontaneous general movements of preterm infants.

Characteristics of general movements in preterm infants assessed by computer-based video analysis

BACKGROUND

Previous evidence suggests that the variability of the spatial center of infant movements, calculated by computer-based video analysis software, can identify fidgety general movements (GMs) and predict cerebral palsy.

AIM

To evaluate whether computer-based video analysis quantifies specific characteristics of normal fidgety movements as opposed to writhing general movements.

METHODS

A longitudinal study design was applied. Twenty-seven low-to moderate-risk preterm infants (20 boys, 7 girls; mean gestational age 32 [SD 2.7, range 27-36] weeks, mean birth weight 1790 grams [SD 430g, range 1185-2700g]) were videotaped at the ages of 3-5 weeks (period of writhing GMs) and 10-15 weeks (period of fidgety GMs) post term. GMs were classified according to Prechtl's general movement assessment method (GMA) and by computer-based video analysis. The variability of the centroid of motion (C_SD), derived from differences between subsequent video frames, was calculated by means of computer-based video analysis software; group mean differences between GM periods were reported.

RESULTS

The mean variability of the centroid of motion (C_SD) determined by computer-based video analysis was 7.5% lower during the period of fidgety GMs than during the period of writhing GMs (p = 0.004).

CONCLUSION

Our findings support that the variability of the centroid of motion reflects small and variable movements evenly distributed across the body, and hence shows that computer-based video analysis qualifies for assessment of direction and amplitude of FMs in young infants.

Fetal face as important indicator of fetal brain function

Fetuses show various facial expressions, such as blinking, yawning, sucking, mouthing, tongue expulsion, scowling, and smiling, assessed by four-dimensional ultrasound from the early second trimester of pregnancy. Moreover, some fetuses demonstrate emotion-like behaviors as noted in infants, children, and adults. Selective fetal responses to stimuli indicate a high degree of brain development, which is reflected in the facial reactions. The fetal face with its movements and expressions can mirror the fetal brain function and development during different stages of the fetus in utero. The fetal face might represent the key to opening the box containing the secrets of fetal brain function and development. Four-dimensional ultrasound may be an important modality in current and future research on fetal facial expressions and assist in the evaluation of the fetal brain function.

Kinematic characteristics of infant leg movements produced across a full day

Introduction

Our purpose is to directly measure variability in infant leg movement behavior in the natural environment across a full day. We recently created an algorithm to identify an infant-produced leg movement from full-day wearable sensor data from infants with typical development between one and 12 months of age. Here we report the kinematic characteristics of their leg movements produced across a full day.

Methods

Wearable sensor data were collected from 12 infants with typical development for 8–13 h/day. A wearable sensor was attached to each ankle and recorded triaxial accelerometer and gyroscope measurements at 20 Hz. We determined the duration, average acceleration, and peak acceleration of each leg movement and classified its type (unilateral, bilateral synchronous, bilateral asynchronous).

Results

There was a range of leg movement duration (0.23–0.33 s) and acceleration (average 1.59–3.88 m/s², peak 3.10–8.83 m/s²) values produced by infants across visits. Infants predominantly produced unilateral and asynchronous bilateral movements. Our results collected across a full day are generally comparable to kinematic measures obtained by other measurement tools across short periods of time.

Conclusion

Our results describe variable full-day kinematics of leg movements across infancy in a natural environment. These data create a reference standard for the future comparison of infants at risk for developmental delay.

4D ultrasound study of fetal facial expressions in the third trimester of pregnancy

OBJECTIVE

To evaluate the frequencies of fetal facial expressions in the third trimester of pregnancy, when fetal brain maturation and development are progressing in normal healthy fetuses.

METHODS

Four-dimensional (4 D) ultrasound was used to examine the facial expressions of 111 healthy fetuses between 30 and 40 weeks of gestation. The frequencies of seven facial expressions (mouthing, yawning, smiling, tongue expulsion, scowling, sucking, and blinking) during 15-minute recordings were assessed. The fetuses were further divided into three gestational age groups (25 fetuses at 30-31 weeks, 43 at 32-35 weeks, and 43 at ≥36 weeks). Comparison of facial expressions among the three gestational age groups was performed to determine their changes with advancing gestation.

RESULTS

Mouthing was the most frequent facial expression at 30-40 weeks of gestation, followed by blinking. Both facial expressions were significantly more frequent than the other expressions (p < .05). The frequency of yawning decreased with the gestational age after 30 weeks of gestation (p = .031). Other facial expressions did not change between 30 and 40 weeks. The frequency of yawning at 30-31 weeks was significantly higher than that at 36-40 weeks (p < .05). There were no significant differences in the other facial expressions among the three gestational age groups.

CONCLUSIONS

Our results suggest that 4D ultrasound assessment of fetal facial expressions may be a useful modality for evaluating fetal brain maturation and development. The decreasing frequency of fetal yawning after 30 weeks of gestation may explain the emergence of distinct states of arousal.

The Visual Scoring of Sleep in Infants 0 to 2 Months of Age

In March 2014, the American Academy of Sleep Medicine (AASM) Board of Directors requested the Scoring Manual Editorial Board develop rules, terminology, and technical specifications for scoring sleep/wake states in full-term infants from birth to 2 mo of age, cognizant of the 1971 Anders, Emde, and Parmelee Manual for Scoring Sleep in Newborns. On July 1, 2015, the AASM published rules for scoring sleep in infants, ages 0-2 mo. This evidence-based review summarizes the background information provided to the Scoring Manual Editorial Board to write these rules. The Anders Manual only provided criteria for coding physiological and behavioral state characteristics in polysomnograms (PSG) of infants, leaving specific sleep scoring criteria to the individual investigator. Other infant scoring criteria have been published, none widely accepted or used. The AASM Scoring Manual infant scoring criteria incorporate modern concepts, digital PSG recording techniques, practicalities, and compromises. Important tenets are: (1) sleep/wake should be scored in 30-sec epochs as either wakefulness (W), rapid eye movement, REM (R), nonrapid eye movement, NREM (N) and transitional (T) sleep; (2) an electroencephalographic (EEG) montage that permits adequate display of young infant EEG is: F3-M2, F4-M1, C3-M2, C4-M1, O1-M2, O2-M1; additionally, recording C3-Cz, Cz-C4 help detect early and asynchronous sleep spindles; (3) sleep onsets are more often R sleep until 2-3 mo postterm; (4) drowsiness is best characterized by visual observation (supplemented by later video review); (5) wide open eyes is the most crucial determinant of W; (6) regularity (or irregularity) of respiration is the single most useful PSG characteristic for scoring sleep stages at this age; (7) trace alternant (TA) is the only relatively distinctive EEG pattern, characteristic of N sleep, and usually disappears by 1 mo postterm replaced by high voltage slow (HVS); (8) sleep spindles first appear 44-48 w conceptional age (CA) and when present prompt scoring N; (9) score EEG activity in an epoch as "continuous" or "discontinuous" for inter-scorer reliability; (10) score R if four or more of the following conditions are present, including irregular respiration and rapid eye movement(s): (a) low chin EMG (for the majority of the epoch); (b) eyes closed with at least one rapid eye movement (concurrent with low chin tone); (c) irregular respiration; (d) mouthing, sucking, twitches, or brief head movements; and (e) EEG exhibits a continuous pattern without sleep spindles; (11) because rapid eye movements may not be seen on every page, epochs following an epoch of definite R in the absence of rapid eye movements may be scored if the EEG is continuous without TA or sleep spindles, chin muscle tone low for the majority of the epoch; and there is no intervening arousal; (12) Score N if four or more of the following conditions are present, including regular respiration, for the majority of the epoch: (a) eyes are closed with no eye movements; (b) chin EMG tone present; (c) regular respiration; and (d) EEG patterns of either TA, HVS, or sleep spindles are present; and (13) score T sleep if an epoch contains two or more discordant PSG state characteristics (either three NREM and two REM characteristics or two NREM and three REM characteristics). These criteria for ages 0-2 mo represent far more than baby steps. Like all the other AASM Manual rules and specifications none are fixed in stone, all open for debate, discussion and revision with the fundamental goal to provide standards for comparison of methods and results.

COMMENTARY

A commentary on this article appears in this issue on page 291.

White Matter Injury and General Movements in High-Risk Preterm Infants

BACKGROUND AND PURPOSE

Very preterm infants (birth weight, <1500 g) are at increased risk of cognitive and motor impairment, including cerebral palsy. These adverse neurodevelopmental outcomes are associated with white matter abnormalities on MR imaging at term-equivalent age. Cerebral palsy has been predicted by analysis of spontaneous movements in the infant termed "General Movement Assessment." The goal of this study was to determine the utility of General Movement Assessment in predicting adverse cognitive, language, and motor outcomes in very preterm infants and to identify brain imaging markers associated with both adverse outcomes and aberrant general movements.

MATERIALS AND METHODS

In this prospective study of 47 preterm infants of 24-30 weeks' gestation, brain MR imaging was performed at term-equivalent age. Infants underwent T1- and T2-weighted imaging for volumetric analysis and DTI. General movements were assessed at 10-15 weeks' postterm age, and neurodevelopmental outcomes were evaluated at 2 years by using the Bayley Scales of Infant and Toddler Development III.

RESULTS

Nine infants had aberrant general movements and were more likely to have adverse neurodevelopmental outcomes, compared with infants with normal movements. In infants with aberrant movements, Tract-Based Spatial Statistics analysis identified significantly lower fractional anisotropy in widespread white matter tracts, including the corpus callosum, inferior longitudinal and fronto-occipital fasciculi, internal capsule, and optic radiation. The subset of infants having both aberrant movements and abnormal neurodevelopmental outcomes in cognitive, language, and motor skills had significantly lower fractional anisotropy in specific brain regions.

CONCLUSIONS

Aberrant general movements at 10-15 weeks' postterm are associated with adverse neurodevelopmental outcomes and specific white matter microstructure abnormalities for cognitive, language, and motor delays.

Current status of fetal neurodevelopmental assessment: Four-dimensional ultrasound study

With the latest advent of four-dimensional (4-D) ultrasound, fetal neurobehavioral or neurodevelopmental assessment can be easily and readily performed. Using this technique, typical fetal movements and behavioral patterns have become apparent in all three trimesters of pregnancy. In twin pregnancy, 4-D ultrasound facilitates the precise evaluation of inter-twin contact and intra-pair stimulation. New fetal neurobehavioral assessment tests, such as Kurjak's Antenatal Neurodevelopmental Test and the Fetal Observable Movement System, may reflect the normal and abnormal neurological development of the fetus, and will facilitate more precise assessments of fetal neurobehavior or neurodevelopment, and fetal brain and central nervous system functions. In this review article, I also discuss interesting topics regarding maternal and fetal stress, fetal pain, and fetal consciousness. Four-dimensional ultrasound has opened the door to new scientific fields, such as 'fetal neurology' and 'fetal psychology,' and fetal neurobehavioral science is at the dawn of a new era. Knowledge on fetal neurobehavior and neurodevelopment will be advanced through fetal behavioral research using this technique.

Characteristics of antigravity spontaneous movements in preterm infants up to 3 months of corrected age

AIMS

We investigated whether spontaneous antigravity limbs movements in very low birth weight preterm infants were insufficient compared to those in term infants. The relationship between the quality of general movements (GMs) and antigravity limbs movements was also examined.

METHODS

Preterm infants with very low birth weight without central nervous system disorders nor severe respiration disorders, and healthy term infants were recruited. The infants were set in a supine position. The distance between both hands and between both feet, and the height of both hands and feet from the floor were recorded at 1-3 corrected months for preterm infants, and at 1-3 months for term infants by a 3D motion capture system. The measurements were adjusted for body proportions. GMs in preterm and term infants were assessed similarly.

RESULTS

Thirteen preterm and 15 term infants completed the study. In preterm infants, the distance between both hands and between both feet were longer, and the height of both hands and feet were lower than those in term infants in all measurements. In term infants, the height of both hands and feet increased as they developed, but no change was observed in preterm infants. In preterm infants with abnormal GMs, the distance between both hands was longer, and the height of both hands and feet was lower than that in those with normal GMs. There were no such differences between preterm infants with normal GMs and term infants with normal GMs.

CONCLUSION

Antigravity limbs movements in preterm infants within the first 3 month of corrected age were insufficient compared with those in term infants. Furthermore, no improvement with development was observed in preterm infants. In addition, preterm infants with abnormal GMs showed worse antigravity limbs movements than preterm and term infants with normal GMs. The preterm infants with normal GMs could behave similar to the full term infants.

Intra-observer reliability of Prechtl's method for the qualitative assessment of general movements in Taiwanese infants

[Purpose] The aim of this study was to examine the intra-observer reliability for Prechtl's General Movements Assessment in Taiwanese infants. This includes the global General Movements Assessment, the Optimality List for Preterm General Movements and Writhing Movements, and the Assessment of Motor Repertoire-3 to 5 Months. [Subjects and Methods] Fifty-nine videos of 37 infants were observed and rated by one physical therapist twice. [Results] The intra-observer reliability ranged from good to very good for the global General Movements Assessment. The overall intra-observer reliabilities for the total score of the Optimality List from preterm up to postmenstrual age 46 weeks and the total score of the Assessment of Motor Repertoire for postmenstrual age 49 to 60 weeks were both good. [Conclusion] The results suggest that the intra-observer reliability of a certified physical therapist was satisfactory for Prechtl's method in Taiwanese infants.

Relationship between white matter pathology and performance on the General Movement Assessment and the Test of Infant Motor Performance in very preterm infants

BACKGROUND

Cerebral Magnetic Resonance Imaging, the General Movement Assessment, and the Test of Infant Motor Performance are all tools that can predict neurodevelopmental outcome in preterm infants. However, how these tests relate to each other is unclear.

AIMS

To examine the relationship between cerebral Magnetic Resonance Imaging measured at term age, and the General Movement Assessment and Test of Infant Motor Performance measured at 10-15 weeks post-term age.

STUDY DESIGN

Prospectively collected data in a sample of very preterm infants.

SUBJECTS

Fifty-three infants (23 female, 30 male) with a median gestational age of 28 weeks (range: 23-30 weeks) and a median birth weight of 1000 g (range: 515-1465 g).

OUTCOME MEASURES

Test of Infant Motor Performance, General Movement Assessment.

RESULTS

Infants with abnormal white matter were significantly more likely to have both abnormal general movements (p=0.01) and abnormal Test of Infant Motor Performance scores (p=0.001). Infants with abnormal general movements were significantly more likely to have lower Test of Infant Motor Performance Scores (p=0.01).

CONCLUSIONS

Abnormal white matter is related to motor deviations as measured by the General Movement Assessment and the Test of Infant Motor Performance as early as 3 months post-term age in a cohort of preterm infants.

The General Movement Assessment Helps Us to Identify Preterm Infants at Risk for Cognitive Dysfunction

Apart from motor and behavioral dysfunctions, deficits in cognitive skills are among the well-documented sequelae of preterm birth. However, early identification of infants at risk for poor cognition is still a challenge, as no clear association between pathological findings based on neuroimaging scans and cognitive functions have been detected as yet. The Prechtl General Movement Assessment (GMA) has shown its merits for the evaluation of the integrity of the young nervous system. It is a reliable tool for identifying infants at risk for neuromotor deficits. Recent studies on preterm infants demonstrate that abnormal general movements (GMs) also reflect impairments of brain areas involved in cognitive development. The aim of this systematic review was to discuss studies that included (i) the Prechtl GMA applied in preterm infants, and (ii) cognitive outcome measures in six data bases. Seven studies met the inclusion criteria and yielded the following results: (a) children born preterm with consistently abnormal GMs up to 8 weeks after term had lower intelligence quotients at school age than children with an early normalization of GMs; (b) from 3 to 5 months after term, several qualitative, and quantitative aspects of the concurrent motor repertoire, including postural patterns, were predictive of intelligence at 7–10 years of age. These findings in 428 individuals born preterm suggest that normal GMs along with a normal motor repertoire during the first months after term are markers for normal cognitive development until at least age 10.