Early Motor Repertoire of Very Preterm Infants and Relationships with 2-Year Neurodevelopment

Diagnostic accuracy of Ages and Stages Questionnaire, Third Edition to identify abnormal or delayed gross motor development in high-risk infants

AIM

To investigate the diagnostic accuracy of parent-completed Ages and Stages Questionnaire, Third Edition (ASQ-3) to identify abnormal or delayed gross motor development in infants born less than 1000 g or less than 28 weeks gestation.

METHODS

Prospective cohort study of high-risk infants comparing ASQ-3 as the index test with concurrent score on Alberta Infant Motor Scale (AIMS) as the reference standard, at 4-, 8- and 12-month corrected (post-term) age. Reference standard positivity cut-offs were 'Abnormal motor development' (AIMS Clinical Range) and 'Motor delay' (AIMS score >1 SD below mean, not captured in Clinical Range).

RESULTS

Participating infants (n = 191) had mean gestational age (95% confidence interval (CI)) 26.8 weeks (26.6-27.1) and mean birthweight (95% CI) 870 g (844-896). AIMS rated 51%, 31% and 23% of infants as having 'Abnormal motor development' and 12%, 28% and 13% with 'Motor delay', at 4, 8 and 12 months, respectively. Diagnostic accuracy of ASQ-3 to identify abnormal motor development was acceptable for older infants only if 'Monitor' cut-off was used: sensitivity (95% CI) 33% (23-44), 86% (73-95) and 80% (63-92) and specificity (95% CI) 84% (74-92), 76% (66-84), and 76% (67-83) at 4, 8 and 12 months, respectively. ASQ-3 sensitivity to identify motor delay was low.

CONCLUSIONS

ASQ-3 has poor sensitivity to identify abnormal or delayed motor development at 4 months. Using the 'Monitor' cut-off improves the diagnostic accuracy of ASQ-3 for identification of older infants with abnormal motor development who are at high risk of motor disability. However, ASQ-3 has poor sensitivity to identify motor delay. Clinical motor assessment of high-risk infants is recommended, particularly in early infancy.

Stability of the Motor Optimality Score Revised (MOS-R) in medically complex infants

BACKGROUND

The Motor Optimality Score-Revised (MOS-R) is a clinical test of infant spontaneous movement at 3-5 months of age and has been associated with neurodevelopmental outcomes in infants with medical complexity. However the stability of the MOS-R tested at different developmental ages is not yet known.

AIM

To determine if the repeated scoring of the MOS-R remained consistent when tested at two developmental ages in young infants.

STUDY DESIGN

In this prospective cohort study, infants were tested twice with the MOS-R between 12 and 13 weeks corrected age (CA) and 14-16 weeks CA. Bland Altman Plots were used to calculate agreement between the scores. Infants were grouped as having higher or lower medical complexity. MOS-R threshold scores were analyzed to assess changes over time within each group using Fisher's exact test.

SUBJECTS

85 infants with history of hospitalization in a neonatal intensive care unit (NICU).

RESULTS

The MOS-R scores had a high agreement with negligible bias (0.058) between timepoints (95 % CI -1.10, 1.22). Using a MOS-R cut point of 19, infants with higher medical complexity were more likely to change groups between timepoints than infants with lower medical complexity (p = 0.008), but this was not significantly different using cut points of 20 or 21.

CONCLUSION

The MOS-R scores were stable when measured repeatedly in infants who were hospitalized in a NICU. Infants with high medical complexity had less stable MOS-R scores using certain cut points than infants with lower medical complexity.

Relationship between early infant motor repertoire and neurodevelopment on the hammersmith infant neurological examination in a developmentally vulnerable First Nations cohort

AIM

To implement a culturally-adapted screening program aimed to determine the ability of infant motor repertoire to predict early neurodevelopment on the Hammersmith Infant Neurological Examination (HINE) and improve Australian First Nations families' engagement with neonatal screening.

METHODS

A prospective cohort of 156 infants (55 % male, mean (standard deviation [SD]) gestational age 33.8 (4.6) weeks) with early life risk factors for adverse neurodevelopmental outcomes (ad-NDO) participated in a culturally-adapted screening program. Infant motor repertoire was assessed using Motor Optimality Score-revised (MOS-R), captured over two videos, 11-13+6 weeks (V1; <14 weeks) and 14-18 weeks (V2; ≥14 weeks) corrected age (CA). At 4-9 months CA neurodevelopment was assessed on the HINE and classified according to age-specific cut-off and optimality scores as; developmentally 'on track' or high chance of either adverse neurodevelopmental outcome (ad-NDO) or cerebral palsy (CP).

RESULTS

Families were highly engaged, 139/148 (94 %) eligible infants completing MOS-R, 136/150 (91 %), HINE and 123 (83 %) both. Lower MOS-R at V2 was associated with reduced HINE scores (β = 1.73, 95 % confidence interval [CI] = 1.03-2.42) and high chance of CP (OR = 2.63, 95%CI = 1.21-5.69) or ad-NDO (OR = 1.38, 95%CI = 1.10-1.74). The MOS-R sub-category 'observed movement patterns' best predicted HINE, infants who score '4' had mean HINE 19.4 points higher than score '1' (95%CI = 12.0-26.9). Receiver-operator curve analyses determined a MOS-R cut-off of <23 was best for identifying mild to severely reduced HINE scores, with diagnostic accuracy 0.69 (sensitivity 0.86, 95%CI 0.76-0.94 and specificity 0.40, 95 % CI 0.25-0.57). A trajectory of improvement on MOS-R (≥2 point increase in MOS-R from 1st to 2nd video) significantly increased odds of scoring optimally on HINE (OR = 5.91, 95%CI 1.16-29.89) and may be a key biomarker of 'on track' development.

INTERPRETATION

Implementation of a culturally-adapted program using evidence-based assessments demonstrates high retention. Infant motor repertoire is associated with HINE scores and the early neurodevelopmental status of developmentally vulnerable First Nations infants.

Correlation between pose estimation features regarding movements towards the midline in early infancy

In infants, spontaneous movement towards the midline (MTM) indicates the initiation of anti-gravity ability development. Markerless 2D pose estimation is a cost-effective, time-efficient, and quantifiable alternative to movement assessment. We aimed to establish correlations between pose estimation features and MTM in early-age infants. Ninety-four infant videos were analysed to calculate the percentage and rate of MTM occurrence. 2D Pose estimation processed the videos and determined the distances and areas using wrist and ankle landmark coordinates. We collected data using video recordings from 20 infants aged 8-16 weeks post-term age. Correlations between MTM observations and distance values were evaluated. Differences in areas between groups of videos showing MTM and no MTM in the total, lower-limb, and upper-limb categories were examined. MTM observations revealed common occurrences of hand-to-trunk and foot-to-foot movements. Weak correlations were noted between limb distances to the midbody imaginary line and MTM occurrence values. Lower MTM showed significant differences in the lower part (p = 0.003) and whole area (p = 0.001). Video recording by parents or guardians could extract features using 2D pose estimation, assisting in the early identification of MTM in infants. Further research is required to assess a larger sample size with the diversity of MTM motor behaviour, and later developmental skills, and collect data from at-risk infants.

Infant movement classification through pressure distribution analysis

BACKGROUND

Aiming at objective early detection of neuromotor disorders such as cerebral palsy, we propose an innovative non-intrusive approach using a pressure sensing device to classify infant general movements. Here we differentiate typical general movement patterns of the "fidgety period" (fidgety movements) vs. the "pre-fidgety period" (writhing movements).

METHODS

Participants (N = 45) were sampled from a typically-developing infant cohort. Multi-modal sensor data, including pressure data from a pressure sensing mat with 1024 sensors, were prospectively recorded for each infant in seven succeeding laboratory sessions in biweekly intervals from 4 to 16 weeks of post-term age. 1776 pressure data snippets, each 5 s long, from the two targeted age periods were taken for movement classification. Each snippet was pre-annotated based on corresponding synchronised video data by human assessors as either fidgety present or absent. Multiple neural network architectures were tested to distinguish the fidgety present vs. fidgety absent classes, including support vector machines, feed-forward networks, convolutional neural networks, and long short-term memory networks.

RESULTS

Here we show that the convolution neural network achieved the highest average classification accuracy (81.4%). By comparing the pros and cons of other methods aiming at automated general movement assessment to the pressure sensing approach, we infer that the proposed approach has a high potential for clinical applications.

CONCLUSIONS

We conclude that the pressure sensing approach has great potential for efficient large-scale motion data acquisition and sharing. This will in return enable improvement of the approach that may prove scalable for daily clinical application for evaluating infant neuromotor functions.

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.

Motor repertoire in 3- to 5- month-old infants with prenatal exposure to syphilis and toxoplasmosis

AIM

To characterize the motor repertoire of 3- to 5-month-old infants who were prenatally exposed to the infectious agents of syphilis and toxoplasmosis.

METHODS

Exploratory observational study that evaluated 15 exposed infants (34.4 ± 3.5 weeks gestation) recruited from a referral center. Age assessment ranged 12-20 (median 12) weeks post-term. General Movement Assessment, including the Motor Optimality Score-Revised (MOS-R), was used to assess the global quality of fidgety movements (FMs) and to quantify and detail coexisting motor patterns. Clinical variables were also collected. Later motor outcomes were obtained from medical reports when possible.

RESULTS

MOS-R ranged 10-26 (median 24). There was a higher proportion of infants with normal (80.0 %) than aberrant FMs, but the proportion of infants with reduced MOS-R (80.0 %) was higher compared to optimal MOS-R. One infant with aberrant FMs was later diagnosed with cerebral palsy. Only 13.3 % of the infants showed smooth and fluent movement character. All observed tongue movements were abnormal.

CONCLUSION

Infants had predominantly normal FMs, but with reduced MOS-R and abnormalities in the coexisting motor repertoire.

Reliability of the Motor Optimality Score-Revised: A study of infants at elevated likelihood for adverse neurological outcomes

AIM

To assess the inter-assessor reliability of the Motor Optimality Score-Revised (MOS-R) when used in infants at elevated likelihood for adverse neurological outcome.

METHODS

MOS-R were assessed in three groups of infants by two assessors/cohort. Infants were recruited from longitudinal projects in Sweden (infants born extremely preterm), India (infants born in low-resource communities) and the USA (infants prenatally exposed to SARS-CoV-2). Intraclass correlation coefficients (ICC) and kappa (κw) were applied. ICC of MOS-R subcategories and total scores were presented for cohorts together and separately and for age-spans: 9-12, 13-16 and 17-25-weeks post-term age.

RESULTS

252 infants were included (born extremely preterm n = 97, born in low-resource communities n = 97, prenatally SARS-CoV-2 exposed n = 58). Reliability of the total MOS-R was almost perfect (ICC: 0.98-0.99) for all cohorts, together and separately. Similar result was found for age-spans (ICC: 0.98-0.99). Substantial to perfect reliability was shown for the MOS-R subcategories (κw: 0.67-1.00), with postural patterns showing the lowest value 0.67.

CONCLUSION

The MOS-R can be used in high-risk populations with substantial to perfect reliability, both in regards of total/subcategory scores as well as in different age groups. However, the subcategory postural patterns as well as the clinical applicability of the MOS-R needs further study.

Mobile Solutions for Clinical Surveillance and Evaluation in Infancy-General Movement Apps

The Prechtl General Movements Assessment (GMA) has become a clinician and researcher toolbox for evaluating neurodevelopment in early infancy. Given that it involves the observation of infant movements from video recordings, utilising smartphone applications to obtain these recordings seems like the natural progression for the field. In this review, we look back on the development of apps for acquiring general movement videos, describe the application and research studies of available apps, and discuss future directions of mobile solutions and their usability in research and clinical practice. We emphasise the importance of understanding the background that has led to these developments while introducing new technologies, including the barriers and facilitators along the pathway. The GMApp and Baby Moves apps were the first ones developed to increase accessibility of the GMA, with two further apps, NeuroMotion and InMotion, designed since. The Baby Moves app has been applied most frequently. For the mobile future of GMA, we advocate collaboration to boost the field's progression and to reduce research waste. We propose future collaborative solutions, including standardisation of cross-site data collection, adaptation to local context and privacy laws, employment of user feedback, and sustainable IT structures enabling continuous software updating.

Early spontaneous movements and spatiotemporal gait characteristics in preterm children

This study aimed to analyze spatiotemporal gait characteristics of preterm children from 3 to 4 years of age according to different gestational age groups and to examine the relationship between the detailed general movements assessment and spatiotemporal gait characteristics. A total of 74 preterm children, 32 extremely preterm and very preterm (EP-VP, < 32 weeks gestational age) and 42 moderate to late preterm (MLP, 32 to < 37 weeks gestational age), were included in this prospective study, along with 38 term children. Early spontaneous movements of preterm children were assessed from videos at 9-20 weeks post-term according to the general movements assessment, which determines the Motor Optimality Score-Revised (MOS-R). The spatiotemporal gait characteristics of all children were evaluated using the GAITRite^®electronic walkway at self-selected walking speeds. EP-VP children walked with shorter step lengths (p = 0.039), and MLP children walked with greater step length variability (p = 0.003) than their term peers. The MOS-R results were related to step length (r = 0.36, p = 0.042), step length variability (r =  -0.56, p = 0.001), and base of support (r =  -0.37, p = 0.038) in EP-VP children. The MOS-R subcategories, age-adequate movement repertoire, and postural patterns were related to some of the spatiotemporal gait characteristics, including step length, step length variability, and base of support (p < 0.05).  Conclusion: EP-VP and MLP children might catch up to their term peers at 3 to 4 years of age in terms of most gait parameters. In addition to the MOS-R, age-adequate movement repertoire and postural patterns of preterm children without cerebral palsy in early life may be a marker of later neurodevelopmental dysfunction. What is Known: • Preterm children walk with a wider step width, a greater step length asymmetry and step time, and a shorter stride length at 18 to 22 months of age compared with term children at a self-selected speed, while these differences disappear in children 4.5-5 years old and older. What is New: • Early spontaneous movements were related to some spatiotemporal gait characteristics. • Preterm children might catch up to term children at 3-4 years of age in spatiotemporal gait characteristics while walking at a self-selected speed.