Comparison of the Motor Performance and Vestibular Function in Infants with a Congenital Cytomegalovirus Infection or a Connexin 26 Mutation: A Preliminary Study.

OBJECTIVES: Hearing-impaired children are at risk for vestibular damage and delayed motor development. Two major causes of congenital hearing loss are cytomegalovirus (CMV) infection and connexin (Cx) 26 mutations. Comparison of the motor performance and vestibular function between these specific groups is still underexplored. The objective of this study was to investigate the impact of congenital (c)CMV and Cx26 on the motor performance and vestibular function in 6 months old infants. DESIGN: Forty children (mean age 6.7 months; range 4.8 to 8.9 months) participated in this cross-sectional design and were recruited from the Flemish CMV registry. They were divided into five age-matched groups: normal-hearing control, asymptomatic cCMV, normal-hearing symptomatic cCMV, hearing-impaired symptomatic cCMV, and hearing-impaired Cx26. Children were examined with the Peabody Developmental Motor Scales-2 and cervical vestibular-evoked myogenic potential (cVEMP) test. RESULTS: Symptomatic hearing-impaired cCMV children demonstrated a significantly lower gross motor performance compared with the control group (p = 0.005), the asymptomatic cCMV group (p = 0.034), and the Cx26 group (0.016). In this symptomatic hearing-impaired cCMV group, 4 out of 8 children had absent cVEMP responses that were related to the weakest gross motor performance. The Cx26 children showed no significant delay in motor development compared with the control children and none of these children had absent cVEMP responses. CONCLUSIONS: The weakest gross motor performance was found in symptomatic hearing-impaired cCMV-infected children with absent cVEMP responses. These results suggest that abnormal saccular responses are a major factor for this delayed motor development, although more work is needed including comprehensive vestibular function testing to verify this.

Brain Connectomics of Visual-Motor Deficits in Children with Developmental Coordination Disorder.

OBJECTIVE: To extend preliminary findings on associated white matter deficits and structural connectivity in children with developmental coordination disorder (DCD). STUDY DESIGN: Diffusion magnetic resonance imaging-based tractography was used to identify abnormal microstructural properties of specific sensorimotor white matter tracts in 21 children with DCD between 8 and 10 years of age and 20 age- and sex-matched typically developing controls. Graph theoretical analyses were applied to evaluate whole brain connectomics. Associations were also calculated between the tractography/connectome results and visual-motor performance, as measured with the Beery-Buktenica Developmental Test of Visual Motor Integration. RESULTS: Significant positive correlations were obtained between visual-motor trace scores and fractional anisotropy (FA) in the retrolenticular limb of the internal capsule within the group with DCD. Moreover, lower FA in sensorimotor tracts and altered structural connectivity were observed for children with DCD. Compared with controls, subjects with DCD showed decreases in clustering coefficient, and global and local efficiency, suggesting weaker structural network segregation and integration. The degree of decreased global efficiency was significantly associated with poor visual-motor tracing outcomes, above and beyond FA reductions. Specifically, nodal efficiency at the cerebellar lobule VI and right parietal superior gyrus were found significant predictors to discriminate between children with DCD and those with typical development. CONCLUSIONS: Specific white matter alterations and network topology features associate with visual-motor deficits and DCD diagnosis indicating the clinical potential of diffusion magnetic resonance imaging-based metrics for diagnosing DCD.

Neural signature of developmental coordination disorder in the structural connectome independent of comorbid autism.

Children with autism spectrum disorders (ASD) often exhibit motor clumsiness (Developmental Coordination Disorder, DCD), i.e. they struggle with everyday tasks that require motor coordination like dressing, self-care, and participating in sport and leisure activities. Previous studies in these neurodevelopmental disorders have demonstrated functional abnormalities and alterations of white matter microstructural integrity in specific brain regions. These findings suggest that the global organization of brain networks is affected in DCD and ASD and support the hypothesis of a 'dys-connectivity syndrome' from a network perspective. No studies have compared the structural covariance networks between ASD and DCD in order to look for the signature of DCD independent of comorbid autism. Here, we aimed to address the question of whether abnormal connectivity in DCD overlaps that seen in autism or comorbid DCD-autism. Using graph theoretical analysis, we investigated differences in global and regional topological properties of structural brain networks in 53 children: 8 ASD children with DCD (DCD+ASD), 15 ASD children without DCD (ASD), 11 with DCD only, and 19 typically developing (TD) children. We constructed separate structural correlation networks based on cortical thickness derived from Freesurfer. The children were assessed on the Movement-ABC and the Beery Test of Visual Motor Integration. Behavioral results demonstrated that the DCD group and DCD+ASD group scored on average poorer than the TD and ASD groups on various motor measures. Furthermore, although the brain networks of all groups exhibited small-world properties, the topological architecture of the networks was significantly altered in children with ASD compared with DCD and TD. ASD children showed increased normalized path length and higher values of clustering coefficient. Also, paralimbic regions exhibited nodal clustering coefficient alterations in singular disorders. These changes were disorder-specific, and included alterations in clustering coefficient in the isthmus of the right cingulate gyrus and the pars orbitalis of the right inferior frontal gyrus in ASD children, and DCD-related increases in the lateral orbitofrontal cortex. Children meeting criteria for both DCD and ASD exhibited topological changes that were more widespread from those seen in children with only DCD, i.e. children with DCD+ASD showed alterations of clustering coefficient in (para)limbic regions, primary areas, and association areas. The DCD+ASD group showed changes in clustering coefficient in the left association cortex relative to the ASD group. Finally, the DCD+ASD group shared ASD-specific abnormalities in the pars orbitalis of right inferior frontal gyrus, which was hypothesized to reflect atypical emotional-cognitive processing. Our results provide evidence that DCD and ASD are neurodevelopmental disorders with a low degree of overlap in abnormalities in connectivity. The co-occurrence of DCD+ASD was also associated with a distinct topological pattern, highlighting the unique neural signature of comorbid neurodevelopmental disorders.

Examining the impact of cochlear implantation on the early gross motor development of children with a hearing loss.

OBJECTIVE: As deaf children are now implanted at a very early age, the influence of a cochlear implant (CI) on the early motor development of children with a hearing loss becomes relevant. DESIGN: Forty-eight children with a hearing loss were included in this controlled prospective follow-up study and were subdivided into a CI group (n = 23) receiving a CI during the follow-up period and a control group (n = 25) receiving no CI during the follow-up period. All children were assessed around the ages of 6 (T1), 12 (T2), 18 (T3), and 24 (T4) months with a motor test battery consisting of the Peabody Developmental Motor Scales-2 (PDMS-2), Alberta Infant Motor Scales (AIMS) (only at T1 and T2), and Ghent Developmental Balance Test (GDBT) (only at T3 and T4). In addition, collic vestibular-evoked myogenic potential testing was performed in all children. Group differences in PDMS-2 Gross Motor Quotient (GMQ), Fine Motor Quotient, AIMS z score, and GDBT z score were analyzed using Linear Mixed Model (LMM) analysis for repeated measures. RESULTS: For PDMS-2 GMQ, the LMM revealed significant effects for group (p = 0.04), test moment (p < 0.001), and for the interaction between these two factors (p = 0.035). Contrasts indicated that the CI group showed a greater deterioration in PDMS-2 GMQ between T2 and T3 compared with that showed by the control group (p = 0.002). The LMM for PDMS-2 Fine Motor Quotient and AIMS z score showed no significant effects. For GDBT z score, the LMM pointed out significant effects for group (p = 0.013) and test moment (p < 0.001), but no significant interaction between these two factors. Contrasts indicated that the CI group performed significantly weaker than the control group at both test moments (T3 and T4; all p < 0.012) and that both groups showed a significant recovery in GDBTz scores between T3 and T4 (all p < 0.012). CONCLUSIONS: This study shows that the trajectory of gross motor development can be changed in children with a hearing loss after a cochlear implantation. Implanted children show a drop in their gross motor performance within the age range of 6 to 18 months, at which period the majority of the implantations took place, with a tendency of recovery toward the age of 2 years. However, longer follow-up will be necessary to trace whether the implanted children catch up their motor delay in comparison with nonimplanted children with a hearing loss at later age.

Rotatory and collic vestibular evoked myogenic potential testing in normal-hearing and hearing-impaired children.

OBJECTIVES: Vertigo and imbalance are often underestimated in the pediatric population, due to limited communication abilities, atypical symptoms, and relatively quick adaptation and compensation in children. Moreover, examination and interpretation of vestibular tests are very challenging, because of difficulties with cooperation and maintenance of alertness, and because of the sometimes nauseatic reactions. Therefore, it is of great importance for each vestibular laboratory to implement a child-friendly test protocol with age-appropriate normative data. Because of the often masked appearance of vestibular problems in young children, the vestibular organ should be routinely examined in high-risk pediatric groups, such as children with a hearing impairment. Purposes of the present study were (1) to determine age-appropriate normative data for two child-friendly vestibular laboratory techniques (rotatory and collic vestibular evoked myogenic potential [cVEMP] test) in a group of children without auditory or vestibular complaints, and (2) to examine vestibular function in a group of children presenting with bilateral hearing impairment. DESIGN: Forty-eight typically developing children (mean age 8 years 0 months; range: 4 years 1 month to 12 years 11 months) without any auditory or vestibular complaints as well as 39 children (mean age 7 years 8 months; range: 3 years 8 months to 12 years 10 months) with a bilateral sensorineural hearing loss were included in this study. All children underwent three sinusoidal rotations (0.01, 0.05, and 0.1 Hz at 50 degrees/s) and bilateral cVEMP testing. RESULTS: No significant age differences were found for the rotatory test, whereas a significant increase of N1 latency and a significant threshold decrease was noticeable for the cVEMP, resulting in age-appropriate normative data. Hearing-impaired children demonstrated significantly lower gain values at the 0.01 Hz rotation and a larger percentage of absent cVEMP responses compared with normal-hearing children. Seventy-four percent of hearing-impaired children showed some type of vestibular abnormality when examined with a combination of rotatory and cVEMP testing, in contrast to an abnormality rate of 60% with cVEMP and a rate of 49% with rotatory testing alone. CONCLUSIONS: The observed pediatric age correlations underscore the necessity of age-appropriate normative data to guarantee accurate interpretation of test results. The high percentages of abnormal vestibular test results in hearing-impaired children emphasize the importance of vestibular assessment in these children because the integrity of the vestibular system is a critical factor for motor and psychological development.

Social responsiveness in children with developmental coordination disorder.

BACKGROUND: Developmental coordination disorder (DCD) is a neurodevelopmental disorder characterized by deficits in performing motor tasks. Research suggests social skills are also altered. OBJECTIVE: To investigate (1) whether the presence of DCD affects social responsiveness, (2) whether the co-occurrence of autism spectrum disorder (ASD) affects social responsiveness in children with DCD, and (3) whether there is an association between motor performance and social responsiveness in children with DCD. METHODS: Based on parental reports, children aged 5 to 15.5 years were assigned to one of three groups: DCD only (noASD, n = 67), DCD and suspected ASD (sASD, n = 13), and DCD and confirmed ASD (cASD, n = 22). Parental answers to the Social Responsiveness Scale (SRS-2) and the DCD-Questionnaire (DCD-Q) were compared to norm values using one sample t-tests, and between groups using ANOVA and MANOVA. Pearson correlation coefficients explored the relationship between the SRS-2 and DCD-Q in the total group and per group. RESULTS: Compared to norm values, difficulties in all areas of social responsiveness were reported in children with DCD, regardless of group (p<0.001). Compared to the noASD group, more unfavorable SRS-2 total T-scores and poorer DCD-Q scores were observed in sASD and cASD groups. Only in the total group, motor performance showed significant weak to moderate associations with the SRS-2 total T-score and all subscales except for 'social motivation' (r=-0.306 to -0.405; p ≤ 0.02). CONCLUSION: Social responsiveness difficulties are more common in children with DCD and are more severe in the ASD groups. Motor performance and social responsiveness are weak to moderately associated. CLINICAL TRIAL REGISTRATION NUMBER: NCT05092893 (https://clinicaltrials.gov/study/NCT05092893).

Parental report of early features of developmental coordination disorder: A qualitative study.

BACKGROUND: Developmental Coordination Disorder (DCD) is a neurodevelopmental condition usually diagnosed after five years of age. AIMS: To evaluate parent-reported early markers of DCD between birth and six years of age. METHODS AND PROCEDURES: In-depth semi-structured interviews were conducted with parents of twelve children diagnosed with DCD. Up to three interviews were performed per family. The interviews were then transcribed ad-verbatim and analyzed using an inductive thematic analysis approach. OUTCOMES AND RESULTS: The first theme 'Child-specific features' discusses the children's challenges in diverse developmental domains (motor milestones, activities of daily living, play and exploration, fatigue and sleep, participation, sensory processing, coping skills and friendships, and verbal skills), varying in severity for each child and each domain. The second theme 'Features in the context' discusses subtle markers in the direct environment of the children such as quests for explanations and therapy, specific participation choices, concerns by other caregivers, and the emergence of secondary consequences. CONCLUSIONS AND IMPLICATIONS: This study reports the presence of early features of DCD from the first year of life and suggests important topics to discuss with parents in the diagnostic process of DCD.

A cross-sectional study on the neurocognitive outcomes in vestibular impaired school-aged children: are they at higher risk for cognitive deficits?

This study aimed to assess if children with a vestibular impairment (VI) are more prone to have neurocognitive deficits compared to typically developing (TD) peers, taking into account important confounding factors with hearing loss being the most important. The neurocognitive performance of fifteen VI children (6-13 years old) was compared to that of an age-, handedness- and sex-weighted group of TD peers (n = 60). Secondly, their performance was also compared to matched groups of TD and hearing impaired (HI) children to evaluate the involvement of HI. The protocol comprises cognitive tests assessing response inhibition, emotion recognition, visuospatial memory, selective and sustained attention, visual memory and visual-motor integration.Based on the results, the VI group had significantly reduced scores on 'social cognition' (p = 0.018), 'executive functions' (p < 0.01), and 'perceptual-motor functioning' (p = 0.020) compared to their TD and HI peers. For the categories 'complex attention' and 'learning and memory' no differences could be observed. Analogous to the findings of previous literature, the symptoms of a VI are often not limited to the primary functions of the system, but also comprise an impact on emotional and cognitive performance. Therefore, more holistic rehabilitation approaches should be encouraged, with a screening and attention for cognitive, emotional and behavioral dysfunctions in the vestibular population. Since this is one of the first studies to investigate the involvement of a VI in a child's cognitive development, these findings support the need for studies further characterizing the impact of a VI, the underlying pathophysiology and the effect of different rehabilitation procedures.

SOS: a screening instrument to identify children with handwriting impairments.

Poor handwriting has been shown to be associated with developmental disorders such as Developmental Coordination Disorder, Attention Deficit Hyperactivity Disorder, autism, and learning disorders. Handwriting difficulties could lead to academic underachievement and poor self-esteem. Therapeutic intervention has been shown to be effective in treating children with poor handwriting, making early identification critical. The SOS test (Systematic Screening for Handwriting Difficulties) has been developed for this purpose. A child copies a sample of writing within 5 min. Handwriting quality is evaluated using six criteria and writing speed is measured. The Dutch SOS test was administered to 860 Flemish children (7-12 years). Inter- and intrarater reliability was excellent. Test-retest reliability was moderate. A correlation coefficient of 0.70 between SOS and "Concise Assessment Methods of Children Handwriting" test (Dutch version) confirmed convergent validity. The SOS allowed discrimination between typically developing children and children in special education, males and females, and different age groups.

Psychometric properties of the Belgian LDCDQ (LDCDQ-BE) in a population based sample.

BACKGROUND: Developmental Coordination Disorder (DCD) is a neurodevelopmental disorder usually diagnosed at school-age. It is related to secondary consequences urging early identification. The Little Developmental Coordination Questionnaire (LDCDQ) is a tool to identify young children at risk of a later DCD diagnosis. AIMS: To explore psychometric properties and cut-off scores for the Belgian version the LDCDQ (LDCDQ-BE). METHODS AND PROCEDURES: Questionnaires were completed by parents (n = 637) and teachers (n = 249) of children aged 3-5 years in regular schools. Additionally, motor development of 82 children was assessed with the M-ABC-2, Beery-VMI-6 and teacher's Motor Skill Checklist (MSC). OUTCOMES AND RESULTS: The LDCDQ-BE demonstrates excellent internal consistency (Cronbach's α = 0.92), moderate convergent validity with M-ABC-2 (r = 0.42), and weak to moderate concurrent validity to Beery-VMI-6 (r = 0.30-0.31) and teacher's rating on MSC (r = 0.27). Discriminant validity with M-ABC-2 and Beery-VMI-6 subtest Visual-Motor Integration is poor, but moderate with Beery-VMI-6 subtest Motor Coordination (p = 0.023) and MSC (p = 0.021). A fair agreement was established between parent's and teacher's rating (=0.308; p < 0.001). CONCLUSIONS AND IMPLICATIONS: Sensitivity of the LDCDQ-BE is low to moderate. It should be interpreted cautiously as predictive validity in children with DCD has yet to be established.

Participation According to Clinicians Working with Young Children with Developmental Disabilities: A Long Way to Go.

Participation has become an important measure of outcome in child rehabilitation as young children with developmental disabilities are increasingly at risk of decreased participation. Therefore, this study garnered information on clinicians' perspectives regarding perceived facilitators and barriers when rendering participation-based interventions using a qualitative research design. Semi-structured interviews of clinicians (Ns = 12, 25-57 years) were conducted and evaluated via an inductive thematic analysis. Results denote that current mechanisms of providing participation-based interventions resembled traditionally focused interventions; thus, resulting in a knowledge-to-practice gap. Clinicians desired more opportunities to communicate with caregivers and to be able to influence the children' s natural environments. They also identified shortness of time, resources, and rigid health care regulations as barriers hampering the efficacy of participation-based services.

Developmental Coordination Disorder before the Age of Three: A Longitudinal Retrospective Study in a Belgian Center for Developmental Disabilities.

This study aimed to explore the association between developmental coordination disorder (DCD) diagnosed after the age of three and both a standardized motor test­the Alberta Infant Motor Scale (AIMS)­and non-standardized observation of movement quality carried out before the age of three. Children at risk or with developmental concerns were studied retrospectively. Children were excluded in case of a diagnosis, excluding DCD, e.g., cerebral palsy, or IQ < 70. Of the 503 included children, 246 were diagnosed with (at-risk) DCD. Multivariate binary logistic regression revealed a significant association between DCD diagnosis after the age of three and male gender and with different aspects of poor movement quality in different age groups before the age three. Univariate analyses revealed an association between DCD diagnosis and the number of poor movement-quality descriptions at 0−6 months, 6−12 months, and 18 months−3 years but not with the AIMS scores. The MABC-2 scores after the age of three were significantly correlated with the number of poor movement-quality descriptions in age groups 0−6 months and 18 months−3 years and with the AIMS scores in age groups 6−12 months and 12−18 months. The results suggest that DCD can be associated with poor movement quality before the age of three.

The Role of Brain-Derived Neurotrophic Factor (BDNF) in the Relation between Physical Activity and Executive Functioning in Children.

Physical activity (PA) can improve children's executive functioning (EF), which might be caused by increased levels of brain-derived neurotrophic factor (BDNF). This study investigated whether acute and/or chronic PA leads to increased BDNF levels and enhanced EF in children. Methods: In total, 47 children (mean age 9.69 ± 0.60; 46.8% boys) participated. Children performed a maximal exercise test to measure acute PA. Before and after, BDNF was collected and EF was measured. Chronic PA was proxy-reported. Repeated Measures ANOVAs were performed to study the effect of acute PA on BDNF and EF. Mediation analyses were performed to investigate the mediation effect of BDNF on the association between chronic PA and BDNF. Results: A borderline significant effect of acute PA on BDNF was found (F = 3.32, p = 0.075) with an increase in BDNF (+29.58 pg/mL) after acute PA. A significant effect was found for performance on inhibition tasks (Flanker (accuracy +5.67%, p = 0.034) and Go/No-Go (+0.15%, p = 0.022)). No effect of acute PA was found on the EF outcomes. No significant correlation between chronic PA and EFs nor BDNF was found. Conclusions: Acute PA might increase BDNF and improve some EFs (i.e., inhibition) in children. Chronic PA was not associated with EF nor BDNF. Trial Registration Number: NCT02503579.

Exergaming improves balance in children with spastic cerebral palsy with low balance performance: results from a multicenter controlled trial.

PURPOSE: Previous studies investigating the effectiveness of exergame balance-training (using video-games) in children with cerebral palsy (CP) yielded inconsistent results that could be related to underpowered studies. Therefore, in this multicenter intervention study, we investigated whether exergaming improves balance clinically in spastic CP. MATERIALS AND METHODS: In total, 35 children with unilateral or bilateral spastic CP (GMFCS-level I-II) were included (age-range: 7-16 years); 16 at VUMC (trial: NTR6034), 19 at UHG (trial: NCT03219112). All participants received care as usual. The intervention group (n = 24) additionally performed exergame-training; 6-8 weeks home-based X-box One Kinect training focused on balance. Balance performance was assessed with the pediatric balance scale (PBS) and two subscales of the Bruininks-Oseretsky Test of Motor Proficiency-2nd edition ("balance" [BOTbal] and "running speed and agility" [BOTrsa]). Mixed model ANOVAs with between and within factors were used to test differences between and within groups. RESULTS: On group level, no post-intervention differences were found between the intervention and control group (PBS: p = 0.248, ηp2 = 0.040; BOTbal: p = 0.374, ηp2 = 0.024; BOTrsa: p = 0.841, ηp2 = 0.001). Distribution of CP-symptoms (unilateral versus bilateral) did not affect training (PBS: p = 0.373, ηp2 = 0.036; BOTbal: p = 0.127, ηp2 = 0.103; BOTrsa: p = 0.474, ηp2 = 0.024). Children with low baseline balance performance (based on PBS) in the intervention group showed improvements in balance performance after training (PBS: p = 0.003, ηp2 = 0.304; BOTbal: p = 0.008, ηp2 = 0.258), whereas children with high baseline balance performance did not. CONCLUSIONS: This exergame-training resulted in balance improvements for the current population of CP that had a low baseline function.IMPLICATIONS FOR REHABILITATIONExergame-training (training using video-games) shows mixed results in children with cerebral palsy (CP).Children with spastic CP (GMFCS level I-II) with a high baseline balance-level did not show functional balance improvements after this home-based exergame-training, suggesting that these children should not be enrolled in this type of exergame-training protocol.Children with spastic CP (GMFCS level I-II) with a low baseline balance-level showed clinically relevant functional balance improvements after this home-based exergame-training, suggesting that these children can benefit from enrolment in this type of exergame-training protocol to improve their balance.The distribution of CP-symptoms did not affect the effectiveness of this balance exergame-training in children with spastic CP with GMFCS-level I and II.

Participation of young children with developmental disabilities: parental needs and strategies, a qualitative thematic analysis.

OBJECTIVES: Participation refers to a person's involvement in activities and roles that provide interaction with others as well as engagement in family and community activities. Young children with developmental disabilities (DD) such as attention deficit hyperactive disorder, autism spectrum disorder and developmental coordination disorder are limited in their participation compared with their typically developing peers. This study aimed to obtain information regarding parental needs and strategies used to enable their child's participation. DESIGN: A thematic inductive approach with in-depth interviews was used to explore parental experiences. Eleven women and two men, between 30 and 40 years of age, who had a child (4-9 years old) with a DD diagnosis based on Diagnostic and Statistical Manual of Mental Disorders criteria, participated in semistructured interviews. RESULTS: Two central themes emerged: parental needs and parental strategies used to enable their child's participation. Parental needs were the following: increasing awareness, ameliorating parental burden, providing tailored interventions and supporting parents in finding suitable leisure activities. Parental strategies aimed at increasing their child's resiliency, attaining maximal fit between activity requirements and child capacity, and creating inclusive opportunities and awareness. CONCLUSIONS: Understanding what families' needs are and how families use and integrate strategies within the context of their daily lives provides practitioners with insights needed to support families' resiliency in promoting their children's participation. The results have implications for professionals as this information can be used to inform, refine, or tailor participation-based and family-centred services.

Standardized motor assessments before the age of five predicting school-aged motor outcome including DCD: A systematic review.

AIM: Developmental Coordination Disorder (DCD) is a common neurodevelopmental disorder usually diagnosed at primary-school-age. This systematic review aimed to summarize available standardized motor assessments before five years of age predicting DCD, complex Minor Neurological Disorder (cMND) and motor delay assessed by a standardized motor test. METHODS: A systematic search was performed in MEDLINE, CINAHL, WoS, Scopus, CENTRAL and ERIC. A hand search was executed. Only data of non-Cerebral Palsy children was included. RESULTS: At or before two years, the BSID, motor subtests of GMDS, NOMAS, and NSMDA might be valuable in detecting school-aged motor delay, while starting at three years, the PDMS, motor subtests of GMDS, NSDMA, M-ABC-2, and CAMPB show promising results. General movements Assessment is associated with cMND, but does not seem sensitive enough to detect DCD. Predictive values are superior in high-risk groups and improve as children age. However, no assessment instrument reached 80% sensitivity and specificity. CONCLUSION: Standardized motor assessments before five years seem valuable in detecting early motor problems. More longitudinal research commencing in infancy, including multiple assessments over time and the implementation of clear diagnostic criteria is imperative.

Balanced Growth project: a protocol of a single-centre observational study on the involvement of the vestibular system in a child's motor and cognitive development.

INTRODUCTION: The involvement of the vestibular system in the motor and higher (cognitive) performances of typically developing or vestibular-impaired children is currently unknown or has only scarcely been explored. Interestingly, arguments for an interaction between vestibular, motor and cognitive functions in children can also be supported by research on children known for their difficulties in motor and/or cognitive processing (eg, children with neurodevelopmental disorders (NDD)), as they often present with vestibular-like characteristics. Therefore, in order to elucidate this interaction, and to increase the understanding of the pathophysiology and symptomatology of vestibular disorders and NDD in children, the Balanced Growth project was developed. It includes the following objectives: (1) to understand the association between motor skills, cognitive performances and the vestibular function in typically developing school-aged children, with special focus on the added value of the vestibular system in higher cognitive skills and motor competence; (2) to investigate whether a vestibular dysfunction (with/without an additional auditory disease) has an impact on motor skills, cognitive performances and motor-cognitive interactions in children and (3) to assess if an underlying vestibular dysfunction can be identified in school-aged children with NDD, with documentation of the occurrence and characteristics of vestibular dysfunctions in this group of children using an extensive vestibular test battery. METHODS AND ANALYSIS: In order to achieve the objectives of the observational cross-sectional Balanced Growth study, a single-task and dual-task test protocol was created, which will be performed in three groups of school-aged children (6-12 years old): (1) a typically developing group (n=140), (2) (audio) vestibular-impaired children (n=30) and (3) children with an NDD diagnosis (n=55) (ie, autism spectrum disorder, attention deficit/hyperactivity disorder and/or developmental coordination disorder). The test protocol consists of several custom-made tests and already existing validated test batteries and includes a vestibular assessment, an extensive motor assessment, eight neurocognitive tests, a cognitive-motor interaction assessment and includes also additional screenings to control for potential confounding factors (eg, hearing status, intelligence, physical activity, etc). ETHICS AND DISSEMINATION: The current study was approved by the ethics committee of Ghent University Hospital on 4 June 2019 with registration number B670201940165 and is registered at Clinical Trials (clinicaltrials.gov) with identifier NCT04685746. All research findings will be disseminated in peer-reviewed journals and presented at vestibular as well as multidisciplinary international conferences and meetings. TRIAL REGISTRATION NUMBER: NCT04685746.

Hippocampal contribution to early and later stages of implicit motor sequence learning.

Implicit motor sequence learning refers to an important human ability to acquire new motor skills through the repeated performance of a motor sequence. This learning process is characterized by slow, incremental gains of motor performance. The present fMRI study was developed to better delineate the areas supporting these temporal dynamics of learning. By using the serial color matching paradigm, our study focused on the motor level of sequence learning and tracked the time course of learning-related neural changes. Imaging results showed a significant contribution of the left anterior hippocampus in an early sequence acquisition stage (first scanning session) as well as during a later stage with stabilized learning effects (second scanning session). Hippocampal activation significantly correlated with the behavioral learning process and was affected by a change of the motor sequence. These results suggest a strong involvement of the hippocampus in implicit motor sequence learning. On the other hand, a very extensive and bilateral neural network of parietal, temporal and frontal cortical areas (including SMA, pre-SMA) together with parts of the cerebellum and striatum were found to play a role during random visuo-motor task performance.