Early Motor Behavior Research Articles

Clinical and Molecular Spectrum of Autosomal Recessive CA8-Related Cerebellar Ataxia.

Based on a limited number of reported families, biallelic CA8 variants have currently been associated with a recessive neurological disorder named, cerebellar ataxia, mental retardation, and dysequilibrium syndrome 3 (CAMRQ-3). We aim to comprehensively investigate CA8-related disorders (CA8-RD) by reviewing existing literature and exploring neurological, neuroradiological, and molecular observations in a cohort of newly identified patients. We analyzed the phenotype of 27 affected individuals from 14 families with biallelic CA8 variants (including data from 15 newly identified patients from eight families), ages 4 to 35 years. Clinical, genetic, and radiological assessments were performed, and zebrafish models with ca8 knockout were used for functional analysis. Patients exhibited varying degrees of neurodevelopmental disorders (NDD), along with predominantly progressive cerebellar ataxia and pyramidal signs and variable bradykinesia, dystonia, and sensory impairment. Quadrupedal gait was present in only 10 of 27 patients. Progressive selective cerebellar atrophy, predominantly affecting the superior vermis, was a key diagnostic finding in all patients. Seven novel homozygous CA8 variants were identified. Zebrafish models demonstrated impaired early neurodevelopment and motor behavior on ca8 knockout. Our comprehensive analysis of phenotypic features indicates that CA8-RD exhibits a wide range of clinical manifestations, setting it apart from other subtypes within the category of CAMRQ. CA8-RD is characterized by cerebellar atrophy and should be recognized as part of the autosomal-recessive cerebellar ataxias associated with NDD. Notably, the presence of progressive superior vermis atrophy serves as a valuable diagnostic indicator. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Neurotoxic effects of 2-ethylhexyl diphenyl phosphate exposure on zebrafish larvae: Insight into inflammation-driven changes in early motor behavior

The extensive utilization and potential adverse impacts of the replacement flame-retardant 2-Ethylhexyl Diphenyl Phosphate (EHDPP) have raised concerns. Currently, there is limited knowledge regarding the developmental, neurological, and immunotoxic consequences of EHDPP exposure, as well as its potential behavioral outcomes. In this study, we undertook a comprehensive examination and characterization of the toxic effects over the EHDPP concentration range of 14–1400 nM. Our findings unveiled that EHDPP, even at an environmentally relevant concentration of 14 nM, exhibited excitatory neurotoxicity, eliciting a 13.5 % increase in the swimming speed of zebrafish larvae. This effect might be attributed to the potential influence of EHDPP on the release of neurotransmitters like serotonin and dopamine, which, in turn, mediated anxiety-like behavior in the zebrafish larvae. Conversely, sublethal dose EHDPP (1400 nM) exposure significantly suppressed the swimming vigor of zebrafish larvae, accompanied by morphological changes, abnormal behaviors, and alterations in intracerebral molecules. Transcriptomics revealed the underlying mechanism. The utilization of pathway inhibitors reshaped the inflammatory homeostasis and alleviated the toxicity induced by EHDPP exposure, anchoring the pivotal role played by the TLR4/NF-κB signaling pathway in EHDPP-induced adverse changes in zebrafish behavior and neurophysiology. This study observed the detrimental effects of EHDPP on fish sustainability at environmentally relevant concentrations, highlighting the practical significance for EHDPP risk management. Elucidating the toxic mechanisms of EHDPP will contribute to a deeper comprehension of how environmental pollutants can intricately influence human health.

Different developmental insecticide exposure windows trigger distinct locomotor phenotypes in the early life stages of zebrafish

Due to their extensive use and high biological activity, insecticides largely contribute to loss of biodiversity and environmental pollution. The regulation of insecticides by authorities is mainly focused on lethal concentrations. However, sub-lethal effects such as alterations in behavior and neurodevelopment can significantly affect the fitness of individual fish and their population dynamics and therefore deserve consideration. Moreover, it is important to understand the impact of exposure timing during development, about which there is currently a lack of relevant knowledge. Here, we investigated whether there are periods during neurodevelopment of fish, which are particularly vulnerable to insecticide exposure. Therefore, we exposed zebrafish embryos to six different insecticides with cholinergic mode of action for 24 h during different periods of neurodevelopment and measured locomotor output using an age-matched behavior assay. We used the organophosphates diazinon and dimethoate, the carbamates pirimicarb and methomyl as well as the neonicotinoids thiacloprid and imidacloprid because they are abundant in the environment and cholinergic signaling plays a major role during key processes of neurodevelopment. We found that early embryonic motor behaviors, as measured by spontaneous tail coiling, increased upon exposure to most insecticides, while later movements, measured through touch-evoked response and a light-dark transition assay, rather decreased for the same insecticides and exposure duration. Moreover, the observed effects were more pronounced when exposure windows were temporally closer to the performing of the respective behavioral assay. However, the measured behavioral effects recovered after a short period, indicating that none of the exposure windows chosen here are particularly critical, but rather that insecticides acutely interfere with neuronal function at all stages as long as they are present. Overall, our results contribute to a better understanding of risks posed by cholinergic insecticides to fish and provide an important basis for the development of safe regulations to improve environmental health.

Smartphone application links severity of retinopathy of prematurity to early motor behavior in a cohort of high-risk preterm infants

To evaluate the General Movement Assessment (GMA) with the Motor Optimality Score-Revised (MOS-R) as a neurodevelopmental marker in infants with retinopathy of prematurity (ROP). Infants screened prospectively for ROP were evaluated at 3 months' post-term age using a smartphone application to complete the GMA and MOS-R. Results were analyzed by ROP severity. Of 105 enrolled infants, 83 completed the study. Of these, 54 (65%) had any ROP, 32 (39%) had severe ROP, and 13 (16%) had type 1 ROP. The proportion with aberrant GMA was significantly higher in infants with severe ROP (14/32 [44%]) compared with infants who had milder ROP (8/51 [16%]; P = 0.006). Of those with severe ROP, there was no significant difference comparing infants with type 1 ROP treated with bevacizumab (7/13 [54%]) to infants with type 2 ROP without treatment (7/19 [37%]; P = 0.47). Although the presence of any ROP, stage of ROP, and severe ROP each predicted lower MOS-R scores on univariate analyses, only severe bronchopulmonary dysplasia and markers of brain injury remained significant in the multivariate analysis. The GMA was a convenient, short-term method of data collection with low attrition. Although severe ROP initially appeared linked to poor early motor scores, this association is likely confounded by neurological and respiratory complications, which frequently accompany severe ROP.

Transitions of motor neuron activities during Ciona development.

Motor neurons (MNs) are one of the most important components of Central Pattern Generators (CPG) in vertebrates (Brown, Proceedings of The Royal Society B: Biological Sciences (The Royal Society), 1911, 84(572), 308-319). However, it is unclear how the neural activities of these components develop during their embryogenesis. Our previous study revealed that in Ciona robusta (Ciona intestinalis type A), a model organism with a simple neural circuit, a single pair of MNs (MN2L/MN2R) was determining the rhythm of its spontaneous early motor behavior (developmental stage St.22-24). MN2s are known to be one of the main components of Ciona CPG, though the neural activities of MN2s in the later larval period (St.25-) were not yet investigated. In this study, we investigated the neural activities of MN2s during their later stages and how they are related to Ciona's swimming CPG. Long-term simultaneous Ca2+ imaging of both MN2s with GCaMP6s/f (St.22-34) revealed that MN2s continued to determine the rhythm of motor behavior even in their later larval stages. Their activities were classified into seven phases (I-VII) depending on the interval and the synchronicity of MN2L and MN2R Ca2+ transients. Initially, each MN2 oscillates sporadically (I). As they develop into swimming larvae, they gradually oscillate at a constant interval (II-III), then start to synchronize (IV) and fully synchronize (V). Intervals become longer (VI) and sporadic again during the tail aggression period (VII). Interestingly, 76% of the embryos started to oscillate from MN2R. In addition, independent photostimulations on left and right MN2s were conducted. This is the first report of the live imaging of neural activities in Ciona's developing swimming CPG. These findings will help to understand the development of motor neuron circuits in chordate animals.

Early motor behavior of infants exposed to maternal mental health disorders — A South African perspective

IntroductionOver the past five decades the bulk of research on exposure to maternal mental health disorders and infant neurodevelopment has been generated in high-income countries. The current study included infants, residing in low-income communities in South Africa, born to mothers with a history of psychiatric disorders. AimTo assess the motor behavior of 10- to 20-week-old infants exposed to maternal mental health disorders, and a subgroup of infants with prenatal psychotropic medication exposure. MethodsThe present study is a cross-sectional descriptive study, with a longitudinal subgroup analysis. General Movement Assessment (GMA), including the Motor Optimality Score-Revised (MOS-R), was used at 10–20 weeks corrected age to assess infant motor behavior. ResultsThe study included 112 infants. No significant difference (p = 0.523) was found on the MOS-R between infants exposed to maternal mental health disorders (n = 70) and the comparison group (n = 42). Both the exposed and comparison groups scored within the mildly reduced range on the MOS-R. No significant differences were found in a subgroup of infants with prenatal exposure to multi-class psychotropic medication (n = 17), mono-class psychotropic medication (n = 35) or valproate exposure (n = 10) (p > 0.1). ConclusionNo association was found between exposure to maternal mental health disorders or exposure to psychotropic medication and infant motor behavior at 10–20 weeks post-term age on the MOS-R. Future research should focus on the contribution of exposure to specific classes and types of psychotropic medication on neurodevelopmental outcome of infants in larger cohorts.

A single motor neuron determines the rhythm of early motor behavior in Ciona.

Recent work in tunicate supports the similarity between the motor circuits of vertebrates and basal deuterostome lineages. To understand how the rhythmic activity in motor circuits is acquired during development of protochordate Ciona, we investigated the coordination of the motor response by identifying a single pair of oscillatory motor neurons (MN2/A10.64). The MN2 neurons had Ca2+ oscillation with an ~80-s interval that was cell autonomous even in a dissociated single cell. The Ca2+ oscillation of MN2 coincided with the early tail flick (ETF). The spikes of the membrane potential in MN2 gradually correlated with the rhythm of ipsilateral muscle contractions in ETFs. The optogenetic experiments indicated that MN2 is a necessary and sufficient component of ETFs. These results indicate that MN2 is indispensable for the early spontaneous rhythmic motor behavior of Ciona. Our findings shed light on the understanding of development and evolution of chordate rhythmical locomotion.

Concurrent and predictive validity of the infant motor profile in infants at risk of neurodevelopmental disorders

BackgroundPreterm infants and infants with perinatal brain injury show a higher incidence of neurodevelopmental disorders (NDD). The Infant Motor Profile (IMP) is a clinical assessment which evaluates the complexity of early motor behaviour. More data are needed to confirm its predictive ability and concurrent validity with other common and valid assessments such as the Alberta Infant Motor Scale (AIMS) and Prechtl’s General Movement Assessment (GMA). The present study aims to evaluate the concurrent validity of the IMP with the AIMS, to assess its association with the GMA, to evaluate how the IMP reflects the severity of the brain injury and to compare the ability of the IMP and the AIMS to predict an abnormal outcome in 5-month-old infants at risk of NDD.Methods86 infants at risk of NDD were retrospectively recruited among the participants of two clinical trials. Preterm infants with or without perinatal brain injury and term infants with brain injury were assessed at 3 months corrected age (CA) using the GMA and at 5 months CA using the IMP and the AIMS. The neurodevelopmental outcome was established at 18 months.ResultsResults confirm a solid concurrent validity between the IMP Total Score and the AIMS (Spearman’s ρ 0.76; p < .001) and a significant association between IMP Total Score and the GMA. Unlike the AIMS, the IMP Total score accurately reflects the severity of neonatal brain injury (p < .001) and proves to be the strongest predictor of NDD (p < .001). The comparison of areas under receiver operating characteristic curves (AUC) confirms that the IMP Total score has the highest diagnostic accuracy at 5 months (AUC 0.92). For an optimal IMP Total Score cut-off value of 70, the assessment shows high sensitivity (93%) and specificity (81%) (PPV 84%; NPV 90%).ConclusionsEarly motor behaviour assessed with the IMP is strongly associated with middle-term neurodevelopmental outcome. The present study confirms the concurrent validity of the IMP with the AIMS, its association with the GMA and its ability to reflect brain lesion load, hence contributing to the construct validity of the assessment.Trial registrationNCT01990183 and NCT03234959 (clinicaltrials.gov).

Brain tissue volumes at term-equivalent age are associated with early motor behavior in very preterm infants.

Preterm birth is associated with a wide range of adverse developmental outcomes, including sensory, motor, cognitive and language impairments, and behavioral or attention problems. Subtle motor deficits that might emerge in premature infants with no evident or with mild brain injury encompass qualitative and quantitative aspects of motor behavior. This prospective cohort study provided an evaluation of the relationship between brain tissue volumes revealed by magnetic resonance imaging (MRI) at term-equivalent age and motor behavior in infancy in very preterm infants (total number=40; mean gestational age=28weeks+4days; mean birth weight=1190g) without evident or with mild brain injury. Infants were recruited at birth and assessed at 12months corrected age using the tool for qualitative and quantitative assessment of motor behavior, infant motor profile. The brain tissue was segmented first using advanced segmentation techniques and the volumes were measured by summing the volumes of all voxels belonging to a particular tissue class. The associations between volumetric brain MRI measures with motor behavior were explored using linear regression analyses. Results showed that larger total brain volumes were associated with higher motor score. Similar relationships were documented for parietal lobe, deep gray matter, and cerebellum volumes. Volumetric quantitative data of brain structures may serve as biomarkers for subtle motor deficits described in very preterm born infants without or with mild brain lesions apparent on MRI.

Atypical postural control can be detected via computer vision analysis in toddlers with autism spectrum disorder

Evidence suggests that differences in motor function are an early feature of autism spectrum disorder (ASD). One aspect of motor ability that develops during childhood is postural control, reflected in the ability to maintain a steady head and body position without excessive sway. Observational studies have documented differences in postural control in older children with ASD. The present study used computer vision analysis to assess midline head postural control, as reflected in the rate of spontaneous head movements during states of active attention, in 104 toddlers between 16–31 months of age (Mean = 22 months), 22 of whom were diagnosed with ASD. Time-series data revealed robust group differences in the rate of head movements while the toddlers watched movies depicting social and nonsocial stimuli. Toddlers with ASD exhibited a significantly higher rate of head movement as compared to non-ASD toddlers, suggesting difficulties in maintaining midline position of the head while engaging attentional systems. The use of digital phenotyping approaches, such as computer vision analysis, to quantify variation in early motor behaviors will allow for more precise, objective, and quantitative characterization of early motor signatures and potentially provide new automated methods for early autism risk identification.

Novel BAC Mouse Model of Huntington's Disease with 225 CAG Repeats Exhibits an Early Widespread and Stable Degenerative Phenotype

Unusually large CAG repeat expansions (>60) in exon one of Huntingtin (HTT) are invariably associated with a juvenile-onset form of Huntington's disease (HD), characterized by a more extensive and rapidly progressing neuropathology than the more prevalent adult-onset form. However, existing mouse models of HD that express the full-length Htt gene with CAG repeat lengths associated with juvenile HD (ranging between ~75 to ~150 repeats in published models) exhibit selective neurodegenerative phenotypes more consistent with adult-onset HD. Objective: To determine if a very large CAG repeat (>200) in full-length Htt elicits neurodegenerative phenotypes consistent with juvenile HD. Using a …bacterial artificial chromosome (BAC) system, we generated mice expressing full-length mouse Htt with ~225 CAG repeats under control of the mouse Htt promoter. Mice were characterized using behavioral, neuropathological, biochemical and brain imaging methods. BAC-225Q mice exhibit phenotypes consistent with a subset of features seen in juvenile-onset HD: very early motor behavior abnormalities, reduced body weight, widespread and progressive increase in Htt aggregates, gliosis, and neurodegeneration. Early striatal pathology was observed, including reactive gliosis and loss of dopamine receptors, prior to detectable volume loss. HD-related blood markers of impaired energy metabolism and systemic inflammation were also increased. Aside from an age-dependent progression of diffuse nuclear aggregates at 6 months of age to abundant neuropil aggregates at 12 months of age, other pathological and motor phenotypes showed little to no progression. The HD phenotypes present in animals 3 to 12 months of age make the BAC-225Q mice a unique and stable model of full-length mutant Htt associated phenotypes, including body weight loss, behavioral impairment and HD-like neurodegenerative phenotypes characteristic of juvenile-onset HD and/or late-stage adult-onset HD.

Early complexity supports development of motor behaviors in the first months of life

Complexity in motor behavior is a hallmark of healthy systems. The purpose of this study was to investigate postural complexity during development of early motor behaviors and under two conditions. Twenty-two infants participated from 1 to 6 months of age. Linear and nonlinear measures of displacement of the center of pressure at the base of support were used to quantify magnitude and temporal structure of postural control. Behavioral coding was used to quantify the emergence of midline head control and early reaching. Results suggest that infants have complexity in postural control strategies early in development. This complexity decreases as infants learn motor behaviors, even when magnitude of the postural variability does not change. Infants were able to adapt the magnitude of postural control variability under different conditions. We propose that infants proceed through three stages which support the infant's ability to adapt motor behaviors.

Neurofacilitation of Developmental Reaction (NFDR) Approach: A Practice Framework for Integration / Modification of Early Motor Behavior (Primitive Reflexes) in Cerebral Palsy

A Randomized Controlled trial was done on 30 (CP) children of age range 6 mon to 2 y with an objective to see the efficacy of Neurofacilitation of Developmental Reaction (NFDR) approach over Neurodevelopmental Therapy (NDT) for integration / modification of early motor behavior (Primitive Reflexes) in Cerebral Palsy (CP). The baseline evaluation was done for tone, postural reactions and GMFM. The subjects were randomly allocated to two groups. With group A, NFDR and group B, conventional approach (NDT) was used for 3 mon followed by re-evaluation. Between groups analysis was done and p value was found to be significant. It was concluded that NFDR approach is more effective than NDT for integration / modification of early motor behavior in children with CP.

Glutamate drives the touch response through a rostral loop in the spinal cord of zebrafish embryos

Characterizing connectivity in the spinal cord of zebrafish embryos is not only prerequisite to understanding the development of locomotion, but is also necessary for maximizing the potential of genetic studies of circuit formation in this model system. During their first day of development, zebrafish embryos show two simple motor behaviors. First, they coil their trunks spontaneously, and a few hours later they start responding to touch with contralateral coils. These behaviors are contemporaneous until spontaneous coils become infrequent by 30 h. Glutamatergic neurons are distributed throughout the embryonic spinal cord, but their contribution to these early motor behaviors in immature zebrafish is still unclear. We demonstrate that the kinetics of spontaneous coiling and touch-evoked responses show distinct developmental time courses and that the touch response is dependent on AMPA-type glutamate receptor activation. Transection experiments suggest that the circuits required for touch-evoked responses are confined to the spinal cord and that only the most rostral part of the spinal cord is sufficient for triggering the full response. This rostral sensory connection is presumably established via CoPA interneurons, as they project to the rostral spinal cord. Electrophysiological analysis demonstrates that these neurons receive short latency AMPA-type glutamatergic inputs in response to ipsilateral tactile stimuli. We conclude that touch responses in early embryonic zebrafish arise only after glutamatergic synapses connect sensory neurons and interneurons to the contralateral motor network via a rostral loop. This helps define an elementary circuit that is modified by the addition of sensory inputs, resulting in behavioral transformation.

162. THE EFFECT OF MATERNAL FOLIC ACID SUPPLEMENTATION THROUGHOUT PREGNANCY ON NEURODEVELOPMENT, MOTOR FUNCTION AND BEHAVIOUR OF PROGENY IN THE RAT

Background: Maternal folic acid supplementation (mFAS) during early pregnancy is recommended to reduce the incidence of neural tube defects and has recently been associated with improved neurodevelopment in children. However, the effect on neurodevelopment of mFAS from before conception and throughout pregnancy is unknown. We examined the effect of mFAS throughout the gestational period on postnatal growth, neurodevelopment and early adult motor function and behaviour in rat offspring. Methods: Female Wistar Rats were fed either a control (folic acid 2mg/kg, n=6) or moderate mFAS diet (folic acid 6mg/kg, n=6) from two weeks before mating with Lewis males, until birth of progeny. Male and female progeny (Control=36, mFAS=36) were weighed on postnatal day (PD) 3, 7, 14, 21, 40 and 90, and underwent various tests between PD4 and 14: righting reflex, palm-grasp reflex, negative geotaxis, forelimb hanging, ascent test and eye opening. Locomotor/ exploratory behaviour, motor coordination and anxiety were assessed using an open field test (PD52), rotarod (PD55) and elevated plus maze (PD58) (Control=24, mFAS=24). Results: mFAS did not alter maternal weight gain, litter-size at birth or progeny growth between PD3-90. mFAS tended to increase righting reflex time (p=0.057) and impair ascent ability (p=0.085). Negative geotaxis time was reduced at PD7 but not later (Diet x Age p=0.051). mFAS increased the proportion of progeny with eyes open at PD14 (p=0.008) and tended to increase forelimb hanging time(p=0.097). mFAS did not alter motor learning/function (rotarod), but increased ambulatory and exploratory behaviour (open field test; p=0.027). Conclusions: mFAS delays some early aspects of neurodevelopment including neonatal postural reflex maturation and proprioceptive/vestibular function, but accelerates others such as eye opening. However, the open field test indicated that mFAS improved the offspring's locomotion and exploratory behaviours in adulthood. Further studies will differentiate the neurodevelopmental effects of mFAS around conception from gestation-long mFAS.

Video‐EEG analysis of ictal repetitive grasping in “frontal‐hyperkinetic” seizures

ABSTRACT The aim of this study was to obtain a qualitative and quantitative description of the phenomenon of forced prehension during epileptic seizures (ictal grasping‐ IG) with hyperkinetic semiology. We analysed retrospectively the presurgical, video‐EEG recordings of 35 “frontal hyperkinetic” seizures (FHS) in 14 patients (age range: 9‐48 years) evaluating the features of ictal grasping by means of off‐line, frame‐by‐frame video‐analysis. Ictal grasping was observed in 97.1% of the frontal hyperkinetic seizures in 100% of the patients, with a mean latency of 3.2 seconds with respect to seizure‐onset; a mean number of 7.7 IG per seizure were detected. During the same FHS, both arms could perform IG in an alternating fashion. Grasping was usually preceded by a reaching movement and followed by holding or pulling. The sites of prehension were restricted to relatively few sectors, either on the patient's body (45.5%) or the peri‐personal space (54.5%). In some cases, the grasping was elicited by hand touching. We did not find a consistent relationship between side of hand grasping and side of ictal EEG discharge or MRI lesion. In conclusion, ictal grasping is an extremely frequent clinical manifestation during FHS. It was an early, forced and repetitive motor behavior, without a clear lateralizing value. Ictal grasping appeared with consistent semiological features, similar to voluntary prehension, suggesting a probable ictal release of physiological grasping behavior. [Published with video sequences]

Early motor development in young children with 22q.11 deletion syndrome and a conotruncal heart defect

Velocardiofacial syndrome is identified by a submicroscopic deletion of chromosome 22Q.11 (del22q.11). This study presents data on the early motor development and behaviour of 11 children (8 males, 3 females) with del22q.11 (mean age 41mo, SD 9.7mo) with a congenital heart defect. To control for the impact of the congenital heart defect, a control group of 19 children (15 males, 4 females; mean age 46mo, SD 9mo) with the same types of congenital heart defects but without del22q.11 was selected. Motor development in both groups was measured with the Peabody Developmental Motor Scales‐2. Behaviour was assessed with the Child Behaviour Checklist. Children with del22q.11 scored significantly lower (p&lt;0.05) on motor performance than the children of the control group. Most deficient motor skills were found for the subtests Locomotion and Stationary. On the behaviour questionnaire, a statistically significant (p&lt;0.05) difference between the two groups was found only for the subscale Withdrawn. These data reveal a significant motor delay in many young children with del22q.11, which is not caused by the presence of a congenital heart defect or by behavioural features.

Early motor development in young children with 22q.11 deletion syndrome and a conotruncal heart defect

Velocardiofacial syndrome is identified by a submicroscopic deletion of chromosome 22q.11 (del22q.11). This study presents data on the early motor development and behaviour of 11 children (8 males, 3 females) with del22q.11 (mean age 41mo, SD 9.7mo) with a congenital heart defect. To control for the impact of the congenital heart defect, a control group of 19 children (15 males, 4 females; mean age 46mo, SD 9mo) with the same types of congenital heart defects but without del22q.11 was selected. Motor development in both groups was measured with the Peabody Developmental Motor Scales-2. Behaviour was assessed with the Child Behaviour Checklist. Children with del22q.11 scored significantly lower (p<0.05) on motor performance than the children of the control group. Most deficient motor skills were found for the subtests Locomotion and Stationary. On the behaviour questionnaire, a statistically significant (p<0.05) difference between the two groups was found only for the subscale Withdrawn. These data reveal a significant motor delay in many young children with del22q.11, which is not caused by the presence of a congenital heart defect or by behavioural features.

The assessment of fetal behavior in early pregnancy: comparison between 2D and 4D sonographic scanning

To determine the accuracy of 4D sonography in the assessment of embryonic and early fetal motor activity in the first trimester of normal pregnancy, in comparison to the 2D sonography. Fifty pregnant women between 6-14 weeks of gestation with singleton pregnancy were assigned for the investigation. Two dimensional and four dimensional recordings were displayed on the screen and recorded on the videotape during the 15 minutes observation period. General body, head and limb movements recorded by 2D sonography were notable by 4D technique in the same gestational age. These movements were presented collectively with maximum, minimum, and median frequencies during 15 minutes observation period. Spearman rank order correlation reached statistical significance (P<0.05) between the frequencies of all observed movement patterns assessed by two different techniques. Several movement patterns, such as sideway bending, hiccup, breathing movements, mouth opening and facial movements could be observed only by 2D sonographic technique in this period of gestation. Presently, both 2D and 4D methods are required for the assessment of early fetal motor development and motor behavior. It is reasonable to expect that such technological improvement may provide some new information about the intrauterine motor activity and facilitate the prenatal detection of some neurological disorders.

Neurological reflexes and early motor behavior in rats subjected to neonatal hypoxic–ischemic injury

Severe perinatal hypoxia–ischemia is an important cause of brain injury in both full-term and premature newborns, with a high risk of future behavioral and neurological deficits. The most commonly used animal model of neonatal hypoxia–ischemia is the unilateral ligation of the common carotid artery followed by exposure to hypoxia in 7-day-old rats. In spite of the wide use of this model, lot of contradictions and discrepancies exist between the results obtained by different laboratories regarding behavioral deficits and there are no data regarding the possible delay of the appearance of neurological reflexes and the time-course of reflex performances following neonatal hypoxic–ischemic injury in rats. In the present study we showed that neonatal hypoxia–ischemia retarded the development of somatic growth and several neurological reflexes (ear twitch, grasping, gait and negative geotaxis). Hypoxic animals also displayed retarded performance in righting, geotaxis and gait reflexes. Although hypoxic pups performed worse in most tests for motor coordination, they reached normal levels by 5 weeks of age except in the footfault test. In the open-field, hypoxic animals were generally more active, except at 3 weeks, when activity of normal pups increased enormously as well. Brain areas were significantly reduced in hypoxic animals, but no close correlation was found with behavioral deficits.