Subjective visual vertical and postural capability in children born prematurely

Assessing Postural Control From Birth to Adulthood Among Individuals Born Preterm: A Systematic Review

Premature life exposure, meaning an immature central nervous system, presents a significant challenge for the development of postural control and, in turn, overall motor development. Preventing motor delay thus requires identifying, characterizing, and quantifying deficit in postural control as early as possible. In our study, we reviewed the procedures used in past studies to assess postural control among individuals born preterm, specifically the characterization of participants, the instruments and motor tasks involved, the types of data collected and analyzed, and the outcomes. To that end, we performed a literature search on PubMed, Wiley Online Library, Web of Science, and Scopus using Boolean logic and assessed the quality of the studies with a standardized assessment based on the Strengthening the Reporting of Observational Studies in Epidemiology guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. Of 35 potential studies, 24 were included; all evaluated infants born preterm, but six did not include a control group of full-term infants. Although the heterogeneity of measurements, variability of instruments, and divergence in motor tasks examined limit definitive conclusions based on quantitative synthesis and the generalization of the results, most studies revealed dysfunctional postural control among individuals born preterm.

Longstanding Auditory Sensory and Semantic Differences in Preterm Born Children

More than 10% of births are preterm, and the long-term consequences on sensory and semantic processing of non-linguistic information remain poorly understood. 17 very preterm-born children (born at < 33 weeks gestational age) and 15 full-term controls were tested at 10 years old with an auditory object recognition task, while 64-channel auditory evoked potentials (AEPs) were recorded. Sounds consisted of living (animal and human vocalizations) and manmade objects (e.g. household objects, instruments, and tools). Despite similar recognition behavior, AEPs strikingly differed between full-term and preterm children. Starting at 50ms post-stimulus onset, AEPs from preterm children differed topographically from their full-term counterparts. Over the 108-224ms post-stimulus period, full-term children showed stronger AEPs in response to living objects, whereas preterm born children showed the reverse pattern; i.e. stronger AEPs in response to manmade objects. Differential brain activity between semantic categories could reliably classify children according to their preterm status. Moreover, this opposing pattern of differential responses to semantic categories of sounds was also observed in source estimations within a network of occipital, temporal and frontal regions. This study highlights how early life experience in terms of preterm birth shapes sensory and object processing later on in life.

Language and sensory characteristics are reflected in voice-evoked responses in low birth weight children

BACKGROUND

Children born with very low birth weight (VLBW) are at higher risk for cognitive impairment, including language deficits and sensorimotor difficulties. Voice-evoked response (P1m), which has been suggested as a language development biomarker in young children, remains unexplored for its efficacy in VLBW children. Furthermore, the relation between P1m and sensory difficulties in VLBW children remains unclear.

METHODS

40 children with VLBW were recruited at 5-to-6 years old (26 male, 14 female, mean age of months ± SD, 80.0 ± 4.9). We measured their voice-evoked brain response using child-customized magnetoencephalography (MEG) and examined the relation between P1m and language conceptual inference ability and sensory characteristics.

RESULTS

The final sample comprised 36 children (23 boys, 13 girls; ages 61-86 months; gestational ages 24-36 weeks). As a result of multiple regression analysis, voice-evoked P1m in the left hemisphere was correlated significantly with language ability (β = 0.414 P = 0.015) and sensory hypersensitivity (β = 0.471 P = 0.005).

CONCLUSION

Our findings indicate that the relation between P1m and language conceptual inference ability observed in term children in earlier studies is replicated in VLBW children, and suggests P1m intensity as a biomarker of sensory sensitivity characteristics.

IMPACT

We investigated brain functions related to language development and sensory problems in very low birth-weight children. In very low birth weight children at early school age, brain responses to human voices are associated with language conceptual inference ability and sensory hypersensitivity. These findings promote a physiological understanding of both language development and sensory characteristics in very low birth weight children.

Evaluation of the Relationship between Pain Exposure and Somatosensory Evoked Potentials in Preterm Infants: A Prospective Cohort Study

BACKGROUND AND AIM

First, to compare somatosensory evoked potentials (SEPs) in preterm newborns without major brain injury studied at term equivalent age (TEA) with a term historical control group. Second, to investigate the impact of pain exposure during the first 28 days after birth on SEPs. Third, to evaluate the association between SEPs and Bayley-III at 2 years corrected age (CA).

METHODS

Infants born at <32 weeks' gestational age (GA) were studied with continuous-SEPs. First, SEP differences between preterm and term infants were analyzed. Second, regression analyses were conducted to explore the association between SEPs and painful procedures, and then between SEPs and neurodevelopment.

RESULTS

86 preterm infants were prospectively enrolled. Preterm infants exhibited prolonged N1 latencies, central conduction times (CCTs), lower N1-P1 amplitudes, and more recurrently abnormal SEPs compared to term infants. Higher pain exposure predicted longer N1 latency and slower CCT (all p < 0.005), adjusting for clinical risk factors. Younger GA and postmenstrual age (PMA) at SEP recording were associated with longer N1 latency and lower N1-P1 amplitude (all p < 0.005). A normal SEP at TEA positively predicted cognitive outcome at 2 years CA (p < 0.005).

CONCLUSION

Pain exposure and prematurity were risk factors for altered SEP parameters at TEA. SEPs predicted cognitive outcome.

Assessment of the perception of vertical subjectivity in children born preterm

Children born preterm have increased rates of paediatric mortality and morbidity. Prematurity has been associated with impaired visual perception and visuo-motor integration. The alteration of the perception of verticality translates into alterations of the vestibular system at central and/or peripheral level, which may manifest itself in symptoms such as imbalance, dizziness or even vertigo. The aim of this study was to compare subjective visual vertical (SVV) test scores in children born preterm with those of children born at term at ages between 7 and 10. One hundred ten children with no neurodevelopmental disorder of 7 to 10 years of age were studied using a mobile application on a smartphone attached to a wall by means of a rotating plate. The SVV test was compared between two groups: a group of 55 preterm children (53 very preterm children born under 32 weeks of gestational age and 2 preterm with very low birth weight) and another group of 55 children born at term (after 37 weeks of gestational age). The SVV results were analysed for comparison with respect to prematurity, sex and age. We found no significant differences in the SVV study in the comparison between preterm and term children. In addition, no significant differences were observed regarding sex or age between 7 and 10 years.  Conclusion: We found no alterations in the perception of vertical subjectivity in children between 7 and 10 years of age, with antecedents of very preterm birth and/or very low birth weight. What is Known: • The different studies published so far suggest the existence of balance disorders in premature children, although in most of these studies the children are examined at an age when the vestibular system is not mature and with non-specific tests for the study of the vestibular system. What is New: • We compared the results of the subjective visual vertical (SVV) test in a group of 55 preterm children (53 very preterm children born under 32 weeks of gestational age and 2 preterm with very low weight at birth) and in a group of 55 children born at term (after 37 weeks of gestational age), at the ages of 7 to 10 years and observed no differences. • We conclude that, if there had been any vestibular alterations due to very premature birth, these must have been compensated by the age of 7.

Neonatal pain, thalamic development and sensory processing behaviour in children born very preterm

BACKGROUND

Altered sensory processing is commonly reported in children born very preterm (≤32 weeks' gestational age [GA]). The immature nervous system, particularly the development of connections from the thalamus to the cortex, may show enhanced vulnerability to excessive sensory stimulation, and may contribute to altered sensory processing. Our objective was to determine whether sensory processing assessed at preschool-aged in children born very preterm was predicted by neonatal procedural pain and thalamic development.

METHODS

In a prospective longitudinal cohort study, N = 140 very preterm infants (median GA at birth 28 weeks) underwent MRI early-in-life and again at term-equivalent age. Children returned for assessment at 4.5 years. Parents reported on child sensory processing behaviors on the Short Sensory Profile. General linear models were used to assess factors associated with sensory processing behaviors, adjusting for clinical and demographic factors.

RESULTS

Among extremely preterm neonates (born 24-28 weeks' GA), but not very-preterm neonates (29-32 weeks' GA), more invasive procedures were associated with poorer sensory processing (B = -0.09, 95%CI [-0.17, -0.01] p = 0.03). In the overall cohort, fewer sensory processing problems were associated with greater thalamic growth between birth and term-equivalent age (B = 0.3, 95%CI [0.11, 0.42], p < 0.001). Extremely preterm neonates exposed to a high number of skin-breaking procedures who exhibited slower neonatal thalamic growth displayed the highest sensory processing problems (B = -26.2, 95%CI [-45.96, -6.38], p = 0.01).

CONCLUSION

Early exposure to pain and related alterations in the developing thalamus may be a key factor underlying later sensory problems in children born extremely preterm.

Age-dependent perturbation of the perceptual and postural vertical by visual roll vection and susceptibility to motion sickness in children

Background

The visual contribution to the perceptual and postural vertical is mediated by a multisensory integration process and may relate to children’s susceptibility to motion sickness that is hypothesized to arise from intersensory conflicts.

Objective

To analyze the maturation of visual contribution to the perceptual and postural vertical in conjunction with the motion sickness susceptibility in childhood.

Methods

In 81 healthy children (aged 2–17 years; 57 females), adjustments of the subjective visual vertical and posturographically tested mediolateral displacements of body sway were measured during free upright stance and large-field visual motion stimulation in the roll plane (roll vection). Motion sickness susceptibility was assessed by taking the history of parents and children.

Results

Vection-induced tilts of the visual vertical showed a linear age-dependent decrease with largest tilts in the youngest (2–7 years; median of 20°) and smallest tilts in the oldest age group (13–17 years; median of 9–10°). Analogously, postural tilts as measured by mediolateral body sway were greatest in the youngest and smallest in the oldest age group. In contrast, motion sickness susceptibility was lowest in the youngest and highest in the oldest age group and exhibited an inverse correlation with vection-induced tilts of the visual vertical.

Conclusion

Roll vection-induced tilts of the visual and postural vertical exhibited a similar age-dependent course with the greatest effects in the youngest and the least effects in the oldest age group, the latter of which exhibited the highest susceptibility to motion sickness.

Influence of body mobility on attention networks in school-aged prematurely born children: A controlled trial

School-aged prematurely born children (PC) have a higher risk of academic difficulties, which may be partly explained by attention difficulties. It has been suggested that children's attentional performance might be influenced by their body posture and spontaneous body motion. The aim of this study (ClinicalTrials.gov - NCT03125447) was to test the influence of three body mobility conditions on the three functions of attention (alertness, orienting, and executive control) among school-aged PC vs. term-born children (TC). Notably, 21 PC and 21 TC performed the Attention Network Test for Children in three body mobility conditions, namely, sitting and standing imposed fixed postures and a free-to-move condition. The children's median reaction times were compared between trials (1) with and without alerting cues, (2) with valid and invalid orienting cues, and (3) with and without distracting information, to calculate the performance of alertness, orienting, and executive control, respectively. Results showed that with distracting information, PC exhibited significantly slower responses in the standing-still posture than in the sitting-still posture (1,077 ± 240 vs. 1,175 ± 273 ms, p < 0.05), but not TC. No difference was observed with the free-to-move condition. PC and TC did not significantly differ in alertness or orienting, regardless of body mobility condition. These data suggest that PC must use executive resources to stand still and maintain position, which impairs their performance during executive tasks. We speculate that these results may be related to less developed postural control and motor inhibition in PC.

The influence between gestational age and postural control, a systematic review

The central nervous system (CNS) of preterm infants might have some peculiarities which distinguish it from that of full term infants. The difficulties associated with prematurity are the main cause of deaths all over the world during the new-born period after community-acquired pneumonia, and the second cause of deaths worldwide in children under five years old. Early recognition of signs indicating fragile postural control in premature infants can support understanding and help prevent and early intervention on possible future neuromotor dysfunctions in these subjects. The purpose of this paper is to determine if there is a qualitatively different development of postural control in premature infants without neurological involvement and infants born at term. We conducted a systematic review of longitudinal and cross-sectional case-control studies published between 2010 and March 2020 on this topic. The evaluation of parameters related to postural control was also included. The methodological quality of the selected works was evaluated using the CASPe critical reading programme for cases and controls. PRISMA guidelines for systematic reviews were followed for prematurity and postural control. 16 articles were included. The total sample amounted to 3,460 participants, of which 1,860 in the preterm group, and 1,600 in the control group. All the studies found show a poorer postural control by the group of children born preterm compared to the group of children born at term and one study indicating more limited postural control with higher prematurity. Regarding the methodological quality according to CASPe, those studies exceeding half of the total score were considered of adequate quality.

Parameters characterizing the posture of preterm children in standing and sitting position

BACKGROUND

Systematic observations of fetal posture show that, although for most of the time the fetus does not have a preferred posture, it has a certain repertoire of repeated active postures. The observed postures cannot be considered random configurations of head and limb position: the fetus and the young infant have an active, but variable posture that is relatively unrelated to the orientation of the force of gravity.

MATERIALS AND METHOD

The study included 101 children, aged 6-7, including 50 preterm children, 48 boys and 53 girls (research group) and 51 full-term children; 22 boys and 53 girls (control group). The photogrammetric method with moire effect on Mora 4G CQ Elektronik was used to examine the body posture.

RESULTS

Significant statistical differences in GAMMA (p< 0.001) and KLL (p= 0.020) parameters in preterm children and in control group were noted. Both parameters presented higher value in the control group.

CONCLUSIONS

The posture of preterm children is characterized by a smaller angle of upper thoracic curvature and smaller angle of lumbar lordosis. The posture of preterm children in sitting position is characterized by a smaller angle of thoracic kyphosis. Preterm birth disturbs the development of proper antigravitational mechanism and causes possible posture dysfunctions at the age of 6.

Psychometric Properties of Clinical Tests of Balance and Vestibular-Related Function in Children With Cerebral Palsy

PURPOSE

The purpose of this study was to establish the psychometric properties of clinical tests of balance and vestibular-related function in children with cerebral palsy (CP), aged 7 to 12 years, Gross Motor Function Classification System levels I to III.

METHODS

Forty-two children with CP and 33 children with typical development were examined using Clinical Dynamic Visual Acuity Test, Modified Clinical Test of Sensory Interaction on Balance, Head Impulse Test, Bucket Test, and Northeastern State University College of Optometry oculomotor test. A subgroup was tested twice for reliability. Reference tests included rotary chair and sensory organization test.

RESULTS

Most children with CP had central rather than peripheral vestibular dysfunction. Clinical tests except Northeastern State University College of Optometry oculomotor test had moderate to good reliability, good sensitivity but poor specificity to identify central vestibular-related impairments.

CONCLUSIONS

Tests of balance and vestibular-related function may help guide clinical management of children with CP.

Body Structure, Function, Activity, and Participation in 3- to 6-Year-Old Children Born Very Preterm: An ICF-Based Systematic Review and Meta-Analysis

BACKGROUND

The World Health Organization's International Classification of Functioning, Disability, and Health framework, Children and Youth Version (ICF-CY), provides a valuable method of conceptualizing the multidomain difficulties experienced by children born very preterm (VP). Reviews investigating motor outcomes at preschool age across ICF-CY domains are lacking.

PURPOSE

The purpose of this review is to identify and compare motor outcomes of 3- to 6-year-old children born VP and children born full-term (FT) within the ICF-CY framework.

DATA SOURCES

Four electronic databases and reference lists of included and key articles were searched.

STUDY SELECTION

Studies comparing motor outcomes of 3- to 6-year-old children born VP (<32 weeks' gestation or birth weight <1500 g) with peers born FT were included.

DATA EXTRACTION

Two independent authors extracted data and completed quality assessments.

DATA SYNTHESIS

Thirty-six studies were included. Activity motor performance of children born VP was consistently poorer compared with peers born FT: standardized mean difference (SMD) was -0.71 (95% CI = -0.80 to -0.61; 14 studies, 2056 participants). Furthermore, children born VP had higher relative risk (RR) of motor impairment (RR = 3.39; 95% CI = 2.68 to 4.27; 9 studies, 3466 participants). Body structure and function outcomes were largely unable to be pooled because assessment tools varied too widely. However, children born VP had higher RR of any neurological dysfunction (Touwen Neurological Examination) (RR = 4.55; 95% CI = 1.20 to 17.17; 3 studies, 1363 participants). There were no participation outcome data.

LIMITATIONS

Limitations include the lack of consistent assessment tools used in VP follow-up at preschool age and the quality of the evidence.

CONCLUSIONS

Children born VP experience significant motor impairment across ICF-CY activity and body structure and function domains at preschool age compared with peers born FT. Evidence investigating participation in VP preschool-age populations relative to children born at term is sparse, requiring further research.

Spatial and temporal postural analysis in children born prematurely

The aim of this study was to compare postural stability in a group of preterm-born children aged 4-6 years old and in a group of age-matched full-term control children by exploring both spatial and temporal analysis of the Center of Pressure (CoP). Twenty-nine children born prematurely (mean age: 5.38±0.17) and twenty-nine age-matched full-term control children participated in this study. Postural control was tested on both a stable and an unstable platform (from Framiral^®) in three different visual conditions: eyes open fixating a target, eyes closed, and with vision perturbed by optokinetic stimulation. We observed a significant increase of both surface area and mean velocity of the CoP in pre-term children compared to full-term control children, particularly in an unstable postural condition. The spectral power indices increased significantly in pre-term children with respect to full-term control children, while the cancelling time was not different between the two groups of children tested. We suggested that poor postural stability observed in preterm children could be due to immaturity of the cortical processes (the occipital parietal prefrontal cortex) involved in motor control. Preterm children could have an inappropriate compensation of sensory inputs when they are tested in difficult postural and/or visual conditions.

Developmental study identifies the ages at which the processes involved in the perception of verticality and in postural stability occur

AIM

The aim of this study was to understand the role played by visual information on the development of verticality and postural stability in healthy children.

METHODS

The study comprised 66 healthy children from 4.0 to 15.7 years of age. Postural performances were recorded with a TechnoConcept platform. At the same time, the children's perception of subjective visual vertical (SVV) was recorded while they adjusted a vertical fluorescent line, either in the dark or in the presence of perturbing visual stimuli. Two testing control conditions without an SVV task were also performed by all of the children: static posturographic recording with open eyes and closed eyes.

RESULTS

Postural measurements provided evidence of a correlation between the children's age and the tasks performed. Postural stability improved with age until eight to nine years, and SVV performance improved after 10-11 years. After these ages, postural and SVV capabilities did not change until at least 15 years of age.

CONCLUSION

Our findings suggest that the maturation of cortical and central processes involved in both the perception of verticality and in postural stability took place during childhood. However, maturation occurred later for vertical perception, which could imply delayed maturation of sensory integration processes.