Motor behaviour in infancy is associated with neurological, cognitive, and behavioural function of children born to parents with reduced fertility.

AIM: To evaluate the associations between motor development in infancy and developmental outcomes at school age. METHOD: Participants were 195 children (99 males, 96 females; mean age [SD] 9y 3mo [3mo], range 8y 4mo-10y 11mo) born to couples whose reduced fertility was or was not treated with assisted reproductive technologies. Motor behaviour was assessed at 4, 10, and 18 months with the Infant Motor Profile (IMP). IQ, neurological optimality score (NOS), and behavioural problem scores were measured at 9 years with the Wechsler Abbreviated Scale of Intelligence, minor neurological dysfunction assessment, and the Child Behavior Checklist respectively. RESULTS: Children with a slow developmental trajectory in the IMP-domain adaptability had an IQ 12.6 points lower (95% confidence interval [CI] 4.7-20.4) and an NOS 3.4 points lower (95% CI 0.7-6.2) at 9 years of age than children with typical adaptability development. Children with a slow developmental trajectory in the IMP-domain performance had an IQ 5.0 points lower (95% CI 0.7-9.3) than children with typical performance development. A non-optimal trajectory in IMP-variation and a fluctuating trajectory in IMP-fluency were associated with higher internalizing scores of 3.6 and 5.8 points respectively, than infants with optimal IMP-domain trajectories. INTERPRETATION: In relatively low-risk children, motor behaviour in infancy was associated with neurological, cognitive, and behavioural function at school age.

Atypical general movements in the general population: Prevalence over the last 15 years and associated factors.

AIM: To determine the prevalence of atypical general movements (GMs) in the general population, to examine its time trend and associated factors. METHODS: Participants consisted of 300 infants born in 2016-2018 (current cohort; gestational age 39.4 weeks (27-42); 162 boys), representative of the Dutch population. GMs were assessed at 2-4 months corrected age in terms of GM-complexity (definitely abnormal (DA) or not) and fidgety movements (present or absent). GM-complexity data from a cohort of 455 Dutch infants born in 2001-2002 were used to investigate the time trend. RESULTS: In the current cohort, 10 infants (3%) showed DA GM-complexity and 8 (3%) absent fidgety movements. Only one infant had both GM-impairments (0.3%). The prevalence of DA GM-complexity did not differ from that in the 2001-2002 cohort (adjusted odds ratio (OR) = 1.47 [0.53, 4.06]). DA GM-complexity was associated with maternal smoking (adjusted OR = 3.59 [1.56, 8.28]) and marginally with prematurity (adjusted OR = 2.78 [1.00, 7.74]); absence of fidgety movements was curvilinearly associated with assessment age only (OR = 1.06 [1.01, 1.12]). CONCLUSION: In the general population, the prevalence of DA GM-complexity and absent fidgety movements is 3%. The finding that they rarely co-occur and are associated with different factors indicates that GM-assessment needs to address both aspects.

Prevailing head position to one side in early infancy-A population-based study.

AIM: To determine the prevalence of prevailing head position to one side (PHP) in young infants and to evaluate its associations with reaching performance, neurological condition and perinatal and socio-economic factors. METHODS: Observational study in 500 infants (273 boys) 2-6 months corrected age, representative of the Dutch population (median gestational age 39.7 weeks (27-42); birthweight 3438 g (1120-4950). Prevailing head position to one side and reaching performance were assessed with the Infant Motor Profile; neurological condition with the Standardized Infant NeuroDevelopmental Assessment. Socio-economic information and perinatal information were obtained by questionnaire and medical records. Associations were analysed with uni- and multivariable statistics. RESULTS: Prevailing head position to one side was observed in 100 infants (20%), and its prevalence decreased from 49% at 2 months to 0% at 6 months. Only in infants aged 4-5 months PHP was significantly associated with worse reaching and an at-risk neurological score. Prevailing head position to one side was weakly associated with prenatal substance exposure, post-natal admission to a paediatric ward and paternal native Dutch background. CONCLUSION: Prevailing head position to one side at 2-3 months is a frequently occurring sign with limited clinical significance. Yet, PHP at 4-5 months is associated with a worse functional and neurological condition. Therefore, PHP at 4-5 months could serve as a red flag indicating possible challenges in later development.

Motor development in infancy is related to cognitive function at 4 years of age.

AIM: Evidence is accumulating that motor and cognitive development are interrelated. This study investigates associations between motor development in infancy and cognitive function at 4 years of age. METHOD: This study is part of the Groningen prospective cohort study on the development of children born after assisted reproductive techniques such as in vitro fertilization. The study group consisted of 223 children (119 males, 104 females) born to subfertile couples (median gestational age 39.6wks, range 30-43wks). Motor behaviour was assessed with the Infant Motor Profile (IMP) at 4 months, 10 months, and 18 months. IQ was evaluated at 4 years with the Kaufman Assessment Battery for Children, Second Edition. Latent class growth modelling was used to analyse relations between IMP and IQ scores. RESULTS: Infants with low total IMP scores had an IQ that was 8.9 points lower at 4 years than infants with typical IMP scores (95% confidence interval 3.6-14.1). Also, low scores in the domains of variation and performance were associated with a lower IQ at 4 years of age, by 6.1 points and 13.2 points respectively. INTERPRETATION: Motor development in relatively low-risk infants is associated with cognition at 4 years of age. In particular, low motor variation and performance are associated with a lower IQ at 4 years of age. WHAT THIS PAPER ADDS: Motor development in infancy is directly related to cognitive function at 4 years of age. This relationship is most pronounced for infant motor variation and performance. The size of the differences in IQ is clinically relevant.

Predictive validity of the Standardized Infant NeuroDevelopmental Assessment (SINDA) to identify 4-5 year-old children at risk of developmental delay in a low-risk sample.

BACKGROUND: Early detection of developmental problems is important as it allows for early intervention. Previous studies, in high-risk infants, found high predictive values of atypical scores on the Standardized Infant NeuroDevelopmental Assessment (SINDA) for later neurodevelopmental disorders (i.e., cerebral palsy, intellectual disability). AIMS: The present study explored SINDA's predictive values to identify risk of developmental delay at 4-5 years. STUDY DESIGN: Cohort study. SUBJECTS: 786 low-risk Dutch children (367 boys; median gestational age: 40 (27-42) weeks; mean birth weight: 3455 (SD 577) grams). OUTCOME MEASURES: The SINDA was assessed at 2-12 months and risk of developmental delay was assessed using the Ages and Stages Questionnaire (ASQ) at 4-5 years. SINDA's predictive values were determined for five ASQ domains and the total ASQ score for children at risk of marked (all ASQ domains deviant) and any (one or more ASQ domains deviant) developmental delay. RESULTS: Presence of one atypical SINDA scale score showed low to moderate sensitivities (12-88 %, depending on the SINDA scale and ASQ domain involved), moderate to high specificities (66-94 %), low positive predictive values (PPVs; 3-16 %), and high negative predictive values (NPVs; 95-100 %) for children at risk of marked and any developmental. Presence of multiple atypical SINDA scale scores predicted deviant ASQ domains slightly better (sensitivities = 11-62 %, specificities = 90-98 %, PPVs = 6-30 %, and NPVs = 95-100 %). CONCLUSIONS: In low-risk infants, SINDA's predictive value is low for detecting children at risk of marked and any developmental delay at 4-5 years, as reflected by the low sensitivities. One of the explanations is the relatively low prevalence of developmental delay in low-risk populations. This might have consequences for the application of the SINDA in general healthcare settings (e.g. child health clinics), but further studies are needed to draw this conclusion.

Reliability and concurrent validity of the Infant Motor Profile.

AIM: The Infant Motor Profile (IMP) is a qualitative assessment of motor behaviour in infancy. It consists of five domains: movement variation, variability, fluency, symmetry, and performance. The aim of this study was to assess interobserver reliability and concurrent validity of the IMP with the Alberta Infant Motor Scale (AIMS) and an age-specific neurological examination. METHOD: Fifty-nine preterm infants (25 females, 34 males; median gestational age 29.7wks, median birthweight 1285g) and 146 term infants (74 females, 72 males; median gestational age 40.1wks, birthweight 3500g) were included. Assessments were performed at corrected ages of 4, 6, 10, 12, and 18 months and consisted of the IMP, AIMS, and an age-specific neurological examination. Interobserver reliability was investigated on a sample of 25 video recordings. Non-parametric statistics were used to analyse the data. RESULTS: Interobserver reliability was high (intraclass correlation coefficient 0.95). At all ages, AIMS scores correlated weakly to fairly with total IMP scores (Spearman's ρ 0.36-0.55), but moderately to strongly with scores on the performance domain of the IMP (Spearman's ρ 0.47-0.84). A clear relation was found between total IMP score and outcome of the neurological examination (Kruskal-Wallis p<0.001 at all ages). INTERPRETATION: Interobserver reliability of the IMP is good. Concurrent validity with the AIMS is best for the IMP performance domain. Concurrent validity with age-specific neurological examination is very good.

Longer duration of gestation in term singletons is associated with better infant neurodevelopment.

BACKGROUND: Longer gestation at term and post-term age is associated with increased perinatal mortality. Nonetheless, recent neuroimaging studies indicated that longer gestation is also associated with better functioning of the child's brain. AIMS: to assess whether longer gestation in term and post-term (in short: term) singletons is associated with better infant neurodevelopment. STUDY DESIGN: cross-sectional observational study. SUBJECTS: Participants were all singleton term infants (n = 1563) aged 2-18 months of the IMP-SINDA project that collected normative data for the Infant Motor Profile (IMP) and Standardized Infant NeuroDevelopmental Assessment (SINDA). The group was representative of the Dutch population. OUTCOME MEASURES: Total IMP score was the primary outcome. Secondary outcomes were atypical total IMP scores (scores <15th percentile) and SINDA's neurological and developmental scores. RESULTS: Duration of gestation had a quadratic relationship with IMP and SINDA developmental scores. IMP scores were lowest at a gestation of 38·5 weeks, SINDA developmental scores at 38·7 weeks. Next, both scores increased with increasing duration of gestation. Infants born at 41-42 weeks had significantly less often atypical IMP scores (adjusted OR [95 % CI]: 0·571 [0·341-0·957] and atypical SINDA developmental scores (adjusted OR: 0·366 [0·195-0·688]) than infants born at 39-40 weeks. Duration of gestation was not associated with SINDA's neurological score. CONCLUSIONS: In term singleton infants representative of the Dutch population longer gestation is associated with better infant neurodevelopment scores suggesting better neural network efficiency. Longer gestation in term infants is not associated with atypical neurological scores.

Atypical knee jerk responses in high-risk children: A longitudinal EMG-study.

INTRODUCTION: We previously found that atypical responses to the knee jerk reflex, i.e., tonic responses (TRs), clonus and contralateral responses in very high-risk (VHR) infants were associated with cerebral palsy (CP) at 21 months. The current study aimed for a better understanding of pathophysiology of atypical knee jerk responses by evaluating whether infant atypical knee jerk responses are associated with CP and atypical knee jerk responses at school-age. METHODS: 31 VHR-children, who had also been assessed longitudinally during infancy, and 24 typically developing children, were assessed at 7-10 years (school-age). We continuously recorded surface EMG of thigh muscles during knee jerk responses longitudinally during infancy and once at school-age. Neurological condition was assessed with age-appropriate neurological examinations. It included the diagnosis of CP at 21 months corrected age and school-age. CP's type and severity (Gross Motor Function Classification System (GMFCS)) were reported. RESULTS: Persistent TRs in infancy were associated with CP at school-age. TR prevalence decreased from infancy to childhood. At school-age it was no longer associated with CP. Clonus prevalence in VHR-children did not change with increasing age; it was significantly higher in children without than those with CP. Reflex irradiation was common in all school-age children, and its prevalence in contralateral muscles in VHR-children decreased between infancy and childhood. CONCLUSIONS: In infancy, TRs indicated an increased risk of CP, but at school-age TRs were not associated with CP. In general, spinal hyperexcitability, expressed as reflex irradiation and TRs, decreased between infancy and school-age.

Development of muscle tone impairments in high-risk infants: Associations with cerebral palsy and cystic periventricular leukomalacia.

AIM: To assess the prevalence and development of muscle tone impairments in infants at high risk of developmental disorders, and their associations with cerebral palsy (CP) and cystic periventricular leukomalacia (cPVL). METHOD: Longitudinal exploration of muscle tone in 39 infants at high risk of CP (LEARN2MOVE 0-2 project) mostly due to an early lesion of the brain. Muscle tone was assessed ≥4 times between 0 and 21 months corrected age (CA) with the Touwen Infant Neurological Examination. Diagnosis of CP was determined at 21 months CA. Neonatal neuro-imaging was available. Developmental trajectories were calculated using generalized linear mixed effect models. RESULTS: Infants showed atypical muscle tone in three or four body parts in 93% (172/185) of the assessments. The most prevalent muscle tone pattern was hypotonia of neck and trunk with hypertonia of the limbs (28%). From 7 months CA onwards hypertonia of the arms was associated with CP. Asymmetric arm tone during infancy was associated with unilateral CP. At 18-21 months CA ankle hypertonia was associated with CP at 21 months; leg hypertonia in infancy was not associated with CP. Leg hypertonia was associated with cPVL, regardless of age. INTERPRETATION: High-risk infants due to an early lesion of the brain often present with muscle tone impairment. In these infants, hypertonia and asymmetric muscle tone of the arms were from 7 months onwards associated with the diagnosis of CP at 21 months; hypertonia of the legs was not.

Infant motor behaviour and functional and cognitive outcome at school-age: A follow-up study in very high-risk children.

BACKGROUND: The Infant Motor Profile (IMP) is an appropriate tool to assess and monitor infant motor behaviour over time. Infants at very high risk (VHR) due to a lesion of the brain generally show impaired motor development. They may grow into or out of their neurodevelopmental deficit. AIMS: Evaluate associations between IMP-trajectories, summarised by IMP-scores in early infancy and rates of change, and functional and cognitive outcome at school-age in VHR-children. STUDY DESIGN: Longitudinal study. SUBJECTS: 31 VHR-children, mainly due to a brain lesion, who had multiple IMP-assessments during infancy, were re-assessed at 7-10 years (school-age). OUTCOME MEASURES: Functional outcome was assessed with the Vineland-II, cognition with RAKIT 2. Associations between IMP-trajectories and outcome were tested by multivariable linear regression analyses. RESULTS: When corrected for sex, maternal education and follow-up age, initial scores of total IMP, variation and performance domains, as well as their rates of change were associated with better functional outcome (unstandardised coefficients [95% CI]): 36.44 [19.60-53.28], 33.46 [17.43-49.49], 16.52 [7.58-25.46], and 513.15 [262.51-763.79], 356.70 [148.24-565.15], and 269 [130.57-407.43], respectively. Positive rates of change in variation scores were associated with better cognition at school-age: 34.81 [16.58-53.03]. CONCLUSION: Our study indicated that in VHR-children IMP-trajectories were associated with functional outcome at school-age, and to a minor extent also with cognition. Initial IMP-scores presumably reflect the effect of an early brain lesion on brain functioning, whereas IMP rate of change reflects whether infants are able to grow into or out of their initial neurodevelopmental deficit.

Infant Motor Profile and cerebral palsy: promising associations.

AIM: The Infant Motor Profile (IMP) is a novel qualitative assessment of motor behaviour in infancy. The aim of this study was to determine whether IMP scores throughout infancy differ between children with and without cerebral palsy (CP) at 18 months. Furthermore, we evaluated the predictive ability of IMP scores throughout infancy for CP. METHOD: Fifty-nine preterm (median gestational age 29.7 wk, median birthweight 1285 g) and 30 term infants (median gestational age 40.1 wk, median birthweight 3588 g) were included. IMP assessments were longitudinally performed at (corrected) ages of 4, 6, 10, and 12 months. Neurological outcome was determined at 18 months with the neurological examination according to Hempel. We compared total and domain IMP scores throughout infancy between infants with and without CP. RESULTS: In the term group none of the children was diagnosed with CP at the age of 18 months, in the preterm group eight had CP at 18 months (14%). Three had unilateral spastic CP, and five bilateral spastic CP. Children with CP (n=8) at 18 months had lower IMP scores throughout infancy than children without. These differences were most pronounced for the domains variation and performance. The predictive ability of the total IMP scores throughout infancy for CP was high (area under receiver operating characteristic curve 0.89-0.99) and most pronounced for the variation and performance domains. INTERPRETATION: IMP scores throughout infancy and CP at 18 months are strongly related. In particular, low scores on the variation and performance domains were important indicators for CP. To determine the exact predictive ability of the IMP, further research is needed.

Patterns of atypical muscle tone in the general infant population - Prevalence and associations with perinatal risk and neurodevelopmental status.

BACKGROUND: Muscle tone is an indispensable element in motor development. Its assessment forms an integral part of the infant neurological examination. Knowledge on the prevalence of atypical tone in infancy is lacking. AIM: To assess the prevalence of atypical muscle tone in infancy and of the most common atypical muscle tone patterns, and associations between atypical tone and perinatal risk and neurodevelopmental status. STUDY DESIGN: Cross-sectional study. SUBJECTS: 1100 infants (585 boys; gestational age 39.4 weeks (27.3-42.4)), 6 weeks-12 months corrected age, representative of the Dutch population. OUTCOME MEASURES: Muscle tone and neurodevelopmental status were assessed with the Standardized Infant NeuroDevelopmental Assessment (SINDA). Perinatal information was obtained by questionnaire and medical records. Univariable and multivariable statistics were applied. RESULTS: Ninety-two infants (8%) had atypical muscle tone in 3-4 body parts (impaired pattern), while atypical muscle tone in 1-2 body parts was observed in 50%. Isolated leg hypotonia and isolated arm hypertonia were most common. Isolated arm hypertonia and the impaired pattern were most clearly but only moderately associated with perinatal risk. These patterns were also most clearly associated with lower neurological scores. Only the impaired pattern was associated with lower developmental scores. CONCLUSION: Atypical muscle tone in one or two body parts is common in infancy and has in general little clinical significance. This finding corresponds to the well-known high prevalence of a typical but non-optimal neurological condition. Eight percent of infants show atypical muscle tone in 3-4 body parts. This clinically relevant pattern is associated with perinatal risk and less favourable neurodevelopmental status.

The assessment of minor neurological dysfunction in infancy using the Touwen Infant Neurological Examination: strengths and limitations.

AIM: Little is known of minor neurological dysfunction (MND) in infancy. This study aimed to evaluate the inter-assessor reliability of the assessment of MND with the Touwen Infant Neurological Examination (TINE) and the construct and predictive validity of MND in infancy. METHOD: Inter-assessor agreement was determined in a sample of 40 infants (24 males, 16 females) aged 3 to 12 months (25 born at term: gestational age 37-41wks, median 39; and 15 born preterm, gestational age 24-35wks, median 32). Thirty typically developing term infants (18 males, 12 females; gestational age 37-42wks, median 40) and 59 preterm infants (34 males, 25 females) born at <35 weeks' gestation (gestational age 25-34wks, median 29) participated in the validity study. They were neurologically assessed with the TINE at the corrected ages of 4, 6, 10, and 12 months and with the Hempel assessment at 18 months. RESULTS: The findings indicated that MND can be assessed reliably (inter-assessor agreement: kappa=0.83). MND during infancy was related to prenatal, perinatal, and social factors, and in particular to preterm birth. Neurological condition during infancy was prone to change, but was related to neurological condition at 18 months at all ages tested. INTERPRETATION: We conclude that MND can be determined reliably in infancy. Important considerations in the construct of MND in infancy are its relation to prenatal and perinatal factors, its limited stability, and its moderate predictive value.

Construct validity of the Infant Motor Profile: relation with prenatal, perinatal, and neonatal risk factors.

AIM: The Infant Motor Profile (IMP) is a qualitative assessment of motor behaviour of infants aged 3 to 18 months. The aim of this study was to investigate construct validity of the IMP through the relation of IMP scores with prenatal, perinatal, and neonatal variables, including the presence of brain pathology indicated by neonatal ultrasound imaging of the brain. METHOD: A longitudinal prospective study was performed in a group of 30 term infants (12 females, 18 males; median gestational age 40.1 wks, range 37.6-42 wks) and 59 preterm infants (25 females, 34 males; median gestational age 29.7 wks, range 25-34.7 wks). IMP assessments were performed at (corrected) ages of 4, 6, 10, 12, and 18 months. Socio-economic and perinatal data were collected, which, in the case of preterm infants, included information on periventricular leukomalacia and intraventricular haemorrhage based on neonatal cranial ultrasound. Data were analysed by fitting mixed-effects models. RESULTS: Gestational age, socio-economic status, and 5-minute Apgar scores were significant determinants of IMP scores in the total group of infants (p<0.001, <0.002, and <0.042 respectively). In the subgroup of preterm infants, IMP scores were significantly affected by brain lesions on neonatal ultrasound (p<0.001) and by socio-economic status (p=0.001). INTERPRETATION: The findings support the construct validity of the IMP: IMP scores are clearly associated with relevant determinants of neuromotor function.

Typical general movements at 2 to 4 months: Movement complexity, fidgety movements, and their associations with risk factors and SINDA scores.

BACKGROUND: Movement complexity and the presence of fidgety movements (FMs) during general movements (GMs) both reflect aspects of neurological integrity in early infancy. AIM: To assess interrelations between the degree of movement complexity and characteristics of FMs during typical GMs and to investigate associations between mildly impaired GMs and risk factors and neurodevelopmental condition. STUDY DESIGN: Observational cohort study. SUBJECTS: 283 infants (25 born preterm) at 2-4 months corrected age, representative of the general Dutch population. OUTCOME MEASURES: GMs were classified in terms of GM-complexity (normal or mildly abnormal (MA)) and FMs (clearly present, sporadic, or exaggerated). Concurrent neurological, developmental and socio-emotional status were measured with the Standardized Infant NeuroDevelopmental Assessment (SINDA). RESULTS: Infants with MA GM-complexity had a higher risk of having sporadic FMs and exaggerated FMs. Perinatal complications were not associated with mildly impaired GMs. MA GM-complexity was associated with advanced maternal age (adjusted OR = 2.29 [1.11, 4.76]) and having a non-native Dutch mother (adjusted OR = 2.93 [1.29, 6.64]). It was also associated with atypical neurological (OR = 7.62 [3.51, 16.54]) and developmental scores (OR = 2.38 [1.16, 4.88]). Sporadic and exaggerated FMs were associated with low-to-middle maternal education (adjusted OR = 2.88, [1.45, 5.72]) and having a non-native Dutch father (adjusted OR = 7.16 [1.41, 36.32]), respectively. However, neither sporadic nor exaggerated FMs were associated with the SINDA outcomes. CONCLUSIONS: GM-complexity and FMs are two interrelated but different aspects of GMs. Mild impairments in GM-complexity and FMs share a non-optimal socio-economic background as risk factor, but only MA GM-complexity is associated with a concurrent non-optimal neurodevelopmental condition.

IVF procedures are not, but subfertility is associated with neurological condition of 9-year-old offspring.

In vitro fertilization (IVF) is not associated with neurological abnormalities in offspring's early childhood. Yet, it is unclear whether this is also true for school age. Neither do we know the role of parental subfertility in offspring's neurological development. The present study examined neurological condition at 9 years of 57 singletons born after controlled ovarian hyperstimulation IVF (COH-IVF), 46 singletons born after modified natural cycle IVF (MNC-IVF) and 66 singletons born to subfertile parents after natural conception (Sub-NC). To assess the effect of subfertility, the groups were pooled to form a subfertile group, and compared with a prospectively followed fertile reference group (n = 282). The sensitive Minor Neurological Dysfunction (MND) examination was used, resulting in the detailed Neurological Optimality Score (NOS) and the prevalence of the clinically relevant complex MND. Neurological condition of the three subfertile groups did not differ significantly: median NOS was 53 in each subfertile group and the prevalence of complex MND in the three subfertile groups was 30%, 37% and 36%, respectively. However, the NOS was lower and the prevalence of complex MND higher in children born to subfertile couples than in children of fertile couples (adjusted mean difference [95% CI]: -4.48 [-5.53 to -3.42]) and adjusted OR [95% CI]: 5.13 [2.60-10.16], respectively). We conclude that ovarian hyperstimulation, in vitro procedures, and the combination of both were not associated with a less favourable neurological outcome of 9-year-old singletons. However, the presence of parental subfertility was associated with less favourable neurological outcome of offspring at 9 years follow up.

Myoclonus in childhood-onset neurogenetic disorders: The importance of early identification and treatment.

BACKGROUND: In clinical practice, myoclonus in childhood-onset neurogenetic disorders frequently remains unrecognized, because it is often overshadowed by other neurological features. Since treatment can lead to significant functional improvement, accurate phenotyping is essential. To demonstrate the importance of early identification and treatment, we report on four patients with various childhood-onset neurogenetic disorders suffering from myoclonus. METHODS: We evaluated four patients with established childhood-onset neurogenetic disorders and involuntary jerky movements, who visited our young-onset movement disorder outpatient clinic. RESULTS: We present the clinical data of four patients (aged 8-21 years) with childhood-onset neurogenetic disorders, including ataxia-telangiectasia, Coffin-Lowry syndrome and epileptic encephalopathy due to SCN1A mutations. All four suffered from jerky movements that hampered normal daily activities and that had gone unrecognized for several years. The presence of multifocal myoclonus was confirmed by polymyography. In all patients, treatment resulted in marked improvement of both myoclonus and overall functioning. CONCLUSION: These cases highlight the relevance of actively searching for myoclonus in childhood-onset neurogenetic disorders, even when a molecular diagnosis has already been established. To further improve the awareness and recognition of myoclonus in children, we provide a list of childhood-onset neurogenetic disorders with myoclonus as important associated feature.

Movement variation in infants born following IVF/ICSI with and without ovarian hyperstimulation.

BACKGROUND: The effect of in vitro fertilisation (IVF) on neurodevelopment is not fully understood. Probably, IVF does not affect traditional measures of neurodevelopment in infancy. Recently, an instrument, the Infant Motor Profile (IMP), was developed that evaluates the quality of motor behaviour. It includes the evaluation of movement variation (i.e. movement repertoire size), a parameter reflecting the integrity of cortical connectivity. AIM: To evaluate the effect of ovarian hyperstimulation and the in vitro procedure on movement variation during infancy. STUDY DESIGN: Prospective cohort study. SUBJECTS: Singletons born following IVF or intracytoplasmic sperm injection (ICSI) with conventional controlled ovarian hyperstimulation (COH-IVF/ICSI, n=68), in a modified natural cycle (MNC-IVF/ICSI, n=57) and natural conception born to subfertile couples (Sub-NC, n=90). OUTCOME MEASURES: Children were assessed with the IMP at 4, 10 and 18 months, resulting in a total IMP score and five domain scores: variation, variability, symmetry, fluency and performance. Primary outcome was the domain score variation. RESULTS: A significant effect of study group was observed for the variation score up until 18 months of age (p=0.039). COH-IVF/ICSI children had a significantly lower mean variation score than MNC-IVF/ICSI children (mean difference [95% confidence interval] -1.010 [-1.766; -0.254]). Mean variation scores of COH-IVF/ICSI and Sub-NC children were similar; the same held true for the comparison between MNC-IVF/ICSI and Sub-NC. Total IMP scores and other domain scores of the three groups were similar. CONCLUSION: The present study did not demonstrate a clear effect of ovarian hyperstimulation and the in vitro procedure on movement variation throughout infancy.

Evaluation of neuromotor function in infancy-A systematic review of available methods.

OBJECTIVE: Neuromotor function in infancy can be evaluated in various ways. Assessment instruments are used for early detection of children with a high risk for developmental disorders. Early detection enables clinicians to provide intervention at a young age when plasticity of the nervous system is high. The assessments may also be used to monitor intervention. The present article will review the psychometric properties of methods to assess neuromotor function in infancy. METHOD: A literature search was performed in PubMed, Medline, and PsycINFO (1966-2007) on instruments to assess neuromotor functioning of infants. RESULTS: Fifteen instruments were included and classified into 4 groups: (1) Comprehensive neurological examinations (n = 4). These techniques are widely used, though little is known about their reliability. Their validity in predicting major developmental disorders such as cerebral palsy is good; their predictive validity for minor motor disorders is moderate at best. (2) Procedures with standardized scoring (n = 7). These have good reliability, but only moderate predictive validity for major developmental disorders. No data available for prediction of minor developmental disorders. (3) Observation of milestones (n = 2). Its predictive validity for major developmental disorders is only moderate, whereas reliability is good. (4) Assessment of quality of motor behavior or motor patterns (n = 2). These instruments have the best predictive validity for major and minor developmental motor disorders, but current methods are only useful under the age of 4 months. CONCLUSION: Prediction of developmental outcome at an early age is difficult. In medical evaluations of high-risk infants, the best predictions are achieved through a combination of multiple, complementary tools, that is, achieved milestones, neurological examination and assessment of the quality of motor behavior.

The Infant Motor Profile: a standardized and qualitative method to assess motor behaviour in infancy.

A reliable and valid instrument to assess neuromotor condition in infancy is a prerequisite for early detection of developmental motor disorders. We developed a video-based assessment of motor behaviour, the Infant Motor Profile (IMP), to evaluate motor abilities, movement variability, ability to select motor strategies, movement symmetry, and fluency. The IMP consists of 80 items and is applicable in children from 3 to 18 months. The present study aimed to test intra- and interobserver reliability and concurrent validity of the IMP with the Alberta Infant Motor Scale (AIMS) and Touwen neurological examination. The study group consisted of 40 low-risk term (median gestational age [GA] 40 wks, range 38-42 wks) and 40 high-risk preterm infants (median GA 29.6 wks, range 26-33 wks) with corrected ages 4 to 18 months (31 females, 49 males). Intra- and interobserver agreement of the IMP were satisfactory (Spearman's rho=0.9). Concurrent validity of IMP and AIMS was good (Spearman's rho=0.8, p<0.005). The IMP was able to differentiate between infants with normal neurological condition, simple minor neurological dysfunction (MND), complex MND, and abnormal neurological condition (p<0.005). This means that the IMP may be a promising tool to evaluate neurological integrity during infancy, a suggestion that needs confirmation by means of assessment of larger groups of infants with heterogeneous neurological conditions.