Atypical procedural learning in children with developmental coordination disorder: A combined behavioral and neuroimaging study.

While procedural learning (PL) has been implicated in delayed motor skill observed in developmental coordination disorder (DCD), few studies have considered the impact of co-occurring attentional problems. Furthermore, the neurostructural basis of PL in children remains unclear. We investigated PL in children with DCD while controlling for inattention symptoms, and examined the role of fronto-basal ganglia-cerebellar morphology in PL. Fifty-nine children (6-14 years; nDCD = 19, ncontrol = 40) completed the serial reaction time (SRT) task to measure PL. The Attention-Deficit Hyperactivity Disorder Rating Scale-IV was administered to measure inattention symptoms. Structural T1 images were acquired for a subset of participants (nDCD = 10, ncontrol = 28), and processed using FreeSurfer. Volume was extracted for the cerebellum, basal ganglia, and frontal regions. After controlling for inattention symptoms, the reaction time profile of controls was consistent with learning on the SRT task. This was not the case for those with DCD. SRT task performance was positively correlated with cerebellar cortical volume, and children with DCD trended towards lower cerebellar volume compared to controls. Children with DCD may not engage in PL during the SRT task in the same manner as controls, with this differential performance being associated with atypical cerebellar morphology.

Specific tractography differences in autism compared to developmental coordination disorder.

About 85% of children with autism spectrum disorder (ASD) experience comorbid motor impairments, making it unclear whether white matter abnormalities previously found in ASD are related to social communication deficits, the hallmark of ASD, or instead related to comorbid motor impairment. Here we aim to understand specific white matter signatures of ASD beyond those related to comorbid motor impairment by comparing youth (aged 8-18) with ASD (n = 22), developmental coordination disorder (DCD; n = 16), and typically developing youth (TD; n = 22). Diffusion weighted imaging was collected and quantitative anisotropy, radial diffusivity, mean diffusivity, and axial diffusivity were compared between the three groups and correlated with social and motor measures. Compared to DCD and TD groups, diffusivity differences were found in the ASD group in the mid-cingulum longitudinal and u-fibers, the corpus callosum forceps minor/anterior commissure, and the left middle cerebellar peduncle. Compared to the TD group, the ASD group had diffusivity differences in the right inferior frontal occipital/extreme capsule and genu of the corpus callosum. These diffusion differences correlated with emotional deficits and/or autism severity. By contrast, children with DCD showed unique abnormality in the left cortico-spinal and cortico-pontine tracts.Trial Registration All data are available on the National Institute of Mental Health Data Archive: https://nda.nih.gov/edit_collection.html?id=2254 .

Atypical resting-state functional brain connectivity in children with developmental coordination disorder.

Children with developmental coordination disorder (DCD) present lower abilities to acquire and execute coordinated motor skills. DCD is frequently associated with visual perceptual (with or without motor component) impairments. This magnetoencephalography (MEG) study compares the brain resting-state functional connectivity (rsFC) and spectral power of children with and without DCD. 29 children with DCD and 28 typically developing (TD) peers underwent 2 × 5 min of resting-state MEG. Band-limited power envelope correlation and spectral power were compared between groups using a functional connectome of 59 nodes from eight resting-state networks. Correlation coefficients were calculated between fine and gross motor activity, visual perceptual and visuomotor abilities measures on the one hand, and brain rsFC and spectral power on the other hand. Nonparametric statistics were used. Significantly higher rsFC between nodes of the visual, attentional, frontoparietal, default-mode and cerebellar networks was observed in the alpha (maximum statistics, p = .0012) and the low beta (p = .0002) bands in children with DCD compared to TD peers. Lower visuomotor performance (copying figures) was associated with stronger interhemispheric rsFC within sensorimotor areas and power in the cerebellum (right lobule VIII). Children with DCD showed increased rsFC mainly in the dorsal extrastriate visual brain system and the cerebellum. However, this increase was not associated with their coordinated motor/visual perceptual abilities. This enhanced functional brain connectivity could thus reflect a characteristic brain trait of children with DCD compared to their TD peers. Moreover, an interhemispheric compensatory process might be at play to perform visuomotor task within the normative range.

Subcortical brain structure in children with developmental coordination disorder: A T1-weighted volumetric study.

Developmental coordination disorder (DCD) is a neurodevelopmental disorder occurring in 5-6% of school-aged children. Converging evidence suggests that dysfunction within cortico-striatal and cortico-cerebellar networks may contribute to motor deficits in DCD, yet limited research has examined the brain morphology of these regions. Using T1-weighted magnetic resonance imaging the current study investigated cortical and subcortical volumes in 37 children with DCD, aged 8 to 12 years, and 48 controls of a similar age. Regional brain volumes of the thalamus, basal ganglia, cerebellum and primary motor and sensory cortices were extracted using the FreeSurfer recon-all pipeline and compared between groups. Reduced volumes within both the left and right pallidum (Left: F = 4.43, p = 0.039; Right: F = 5.24, p = 0.025) were observed in children with DCD; however, these results did not withstand correction for multiple comparisons. These findings provide preliminary evidence of altered subcortical brain structure in DCD. Future studies that examine the morphology of these subcortical regions are highly encouraged in order replicate these findings.

Unique deficit in embodied simulation in autism: An fMRI study comparing autism and developmental coordination disorder.

A deficit in pre-cognitively mirroring other people's actions and experiences may be related to the social impairments observed in autism spectrum disorder (ASD). However, it is unclear whether such embodied simulation deficits are unique to ASD or instead are related to motor impairment, which is commonly comorbid with ASD. Here we aim to disentangle how, neurologically, motor impairments contribute to simulation deficits and identify unique neural signatures of ASD. We compare children with ASD (N = 30) to children with Developmental Coordination Disorder (DCD; N = 23) as well as a typically developing group (N = 33) during fMRI tasks in which children observe, imitate, and mentalize about other people's actions. Results indicate a unique neural signature in ASD: during action observation, only the ASD group shows hypoactivity in a region important for simulation (inferior frontal gyrus, pars opercularis, IFGop). However, during a motor production task (imitation), the IFGop is hypoactive for both ASD and DCD groups. For all tasks, we find correlations across groups with motor ability, even after controlling for age, IQ, and social impairment. Conversely, across groups, mentalizing ability is correlated with activity in the dorsomedial prefrontal cortex when controlling for motor ability. These findings help identify the unique neurobiological basis of ASD for aspects of social processing. Furthermore, as no previous fMRI studies correlated brain activity with motor impairment in ASD, these findings help explain prior conflicting reports in these simulation networks.

Motor asymmetry related cerebral perfusion patterns in Parkinson's disease: An arterial spin labeling study.

Persisting asymmetry of motor symptoms are characteristic of Parkinson's disease (PD). We investigated the possible lateralized effects on regional cerebral blood flow (CBF), CBF-connectivity, and laterality index (LI) among PD subtypes using arterial spin labeling (ASL). Forty-four left-sided symptom dominance patients (PDL), forty-eight right-sided symptom dominance patients (PDR), and forty-five matched HCs were included. Group comparisons were performed for the regional normalized CBF, CBF-connectivity and LI of basal ganglia (BA) subregions. The PDL patients had lower CBF in right calcarine sulcus and right supramarginal gyrus compared to the PDR and the HC subjects. Regional perfusion alterations seemed more extensive in the PDL than in the PDR group. In the PDL, correlations were identified between right thalamus and motor severity, between right fusiform gyrus and global cognitive performance. None of correlations survived after multiple comparisons correction. The significantly altered CBF-connectivity among the three groups included: unilateral putamen, unilateral globus pallidus, and right thalamus. LI score in the putamen was significantly different among groups. Motor-symptom laterality in PD may exhibit asymmetric regional and interregional abnormalities of CBF properties, particularly in PDL patients. This preliminary study underlines the necessity of classifying PD subgroups based on asymmetric motor symptoms and the potential application of CBF properties underlying neuropathology in PD.

Areas of white matter hyperintensities and motor symptoms of Parkinson disease.

OBJECTIVE: To determine whether deep white matter and periventricular hyperintensities affect the motor symptoms of Parkinson disease (PD) differently, we analyzed MRI and dopamine transporter imaging. METHODS: We analyzed the medical records of patients with de novo PD who underwent dopamine transporter PET scanning and MRI at their first visit. Deep white matter and periventricular hyperintensities were scored with a visual rating scale, and motor symptoms were assessed by Unified Parkinson's Disease Rating Scale motor score and tremor, rigidity, bradykinesia, and axial symptom subscores. The influence of white matter hyperintensity on motor symptoms was explored using multivariable linear regression models. RESULTS: A total of 93 patients (mean age, 67.2 ± 9.9 years; 44 male) were included and the mean motor score was 25.0 ± 10.8. Subscores for bradykinesia and axial symptoms were correlated with both deep white matter and periventricular hyperintensities scores. Multivariable linear regression models revealed that deep white matter hyperintensities score was significantly associated with subscore for bradykinesia and periventricular hyperintensities score was associated with subscores for bradykinesia and axial symptoms after adjusting for putaminal dopamine transporter availability and clinical factors. CONCLUSIONS: These results demonstrate that deep white matter hyperintensities are associated with bradykinesia and periventricular hyperintensities are associated with bradykinesia and axial symptoms in patients with PD independently of the severity of dopaminergic depletion.

Differences in White Matter Microstructure Among Children With Developmental Coordination Disorder.

Importance: Developmental coordination disorder (DCD) is a motor impairment that significantly interferes with activities of daily living. Little is known about the cause of DCD and how it develops, making it difficult to understand why children with DCD struggle in learning motor skills and to determine the best intervention to optimize function. Objective: To characterize white matter differences using diffusion tensor imaging in children with and without DCD. Design, Setting, and Participants: This cross-sectional study collected diffusion tensor imaging data at BC Children's Hospital Research Institute in Vancouver, British Columbia, Canada, from September 2014 to January 2017. Using a sample of convenience, children with DCD and children without DCD aged 8 to 12 years underwent magnetic resonance imaging. Data analysis was conducted from January 2017 to January 2020. Main Outcomes and Measures: The main outcome measures were diffusion parameters, including fractional anisotropy and mean, axial, and radial diffusivity, which are thought to provide an indirect measure of white matter microstructure. Tract-based spatial statistics, a voxelwise statistical analysis of diffusion parameters, were conducted using a 2-group comparison design matrix with age and attention as covariates. Results: Thirty children without DCD (mean [SD] age, 9.9 [1.4] years; 21 [70%] boys) and 31 children with DCD (mean [SD] age, 10.1 [1.2] years; 26 [84%] boys) were included in the study. Compared with children without DCD, children with DCD were characterized by significantly lower fractional anisotropy and axial diffusivity in regions of white matter pathways associated with motor and sensorimotor processing, including the corticospinal tract (fractional anisotropy: mean [SD], 0.54 [0.03] vs 0.51 [0.03]; P < .001; axial diffusivity: mean [SD], 0.13 [0.98] vs 0.12 [0.46]; P = .01), posterior thalamic radiation at the retrolenticular part of the internal capsule (axial diffusivity: mean [SD], 0.14 [0.57] vs 0.14 [0.44]; P = .01), and cerebellar pathways (eg, superior cerebellar peduncle, fractional anisotropy: mean [SD], 0.49 [0.05] vs 0.46 [0.03]; P = .03; axial diffusivity: mean [SD], 0.14 [0.66] vs 0.14 [0.63]; P = .009). There were no significant differences in mean diffusivity and radial diffusivity between children with and without DCD. Conclusions and Relevance: These findings suggest that children with DCD show significant brain differences in motor and sensorimotor white matter pathways compared with children without DCD. The pattern of diffusion parameters in children with DCD suggests that axonal development may be disrupted in this neurodevelopmental disorder.

Implications of the putamen in pain and motor deficits in complex regional pain syndrome.

Complex regional pain syndrome (CRPS) develops after-limb injury, with persistent pain and deficits in movement frequently co-occurring. The striatum is critical for mediating multiple mechanisms that are often aberrant in CRPS, which includes sensory and pain processing, motor function, and goal-directed behaviors associated with movement. Yet, much remains unknown with regards to the morphological and functional properties of the striatum and its subregions in this disease. Thus, we investigated 20 patients (15 female, age 58 ± 9 years, right-handed) diagnosed with chronic (6+ months of pain duration) CRPS in the right hand and 20 matched, healthy controls with anatomical and resting-state, functional magnetic resonance imaging. In addition, a comprehensive clinical and behavioral evaluation was performed, where each participant's pain, motor function, and medical history were assessed. Complex regional pain syndrome patients harbored significant abnormalities in hand coordination, dexterity, and strength. These clinical pain- and movement-related findings in CRPS patients were concomitant with bilateral decreases in gray matter density in the putamen as well as functional connectivity increases and decreases among the putamen and pre-/postcentral gyri and cerebellum, respectively. Importantly, higher levels of clinical pain and motor impairment were associated with increased putamen-pre-/postcentral gyri functional connectivity strengths. Collectively, these findings suggest that putaminal alterations, specifically the functional interactions with sensorimotor structures, may underpin clinical pain and motor impairment in chronic CRPS patients.

Traumatic Brain Injury Results in Dynamic Brain Structure Changes Leading to Acute and Chronic Motor Function Deficits in a Pediatric Piglet Model.

Traumatic brain injury (TBI) is a leading cause of death and disability in children. Pediatric TBI patients often suffer from crippling cognitive, emotional, and motor function deficits that have negative lifelong effects. The objective of this study was to longitudinally assess TBI pathophysiology using multi-parametric magnetic resonance imaging (MRI), gait analysis, and histological approaches in a pediatric piglet model. TBI was produced by controlled cortical impact in Landrace piglets. MRI data, including from proton magnetic resonance spectroscopy (MRS), were collected 24 hours and 12 weeks post-TBI, and gait analysis was performed at multiple time-points over 12 weeks post-TBI. A subset of animals was sacrificed 24 hours, 1 week, 4 weeks, and 12 weeks post-TBI for histological analysis. MRI results demonstrated that TBI led to a significant brain lesion and midline shift as well as microscopic tissue damage with altered brain diffusivity, decreased white matter integrity, and reduced cerebral blood flow. MRS showed a range of neurochemical changes after TBI. Histological analysis revealed neuronal loss, astrogliosis/astrocytosis, and microglia activation. Further, gait analysis showed transient impairments in cadence, cycle time, % stance, step length, and stride length, as well as long-term impairments in weight distribution after TBI. Taken together, this study illustrates the distinct time course of TBI pathoanatomic and functional responses up to 12 weeks post-TBI in a piglet TBI model. The study of TBI injury and recovery mechanisms, as well as the testing of therapeutics in this translational model, are likely to be more predictive of human responses and clinical outcomes compared to traditional small animal models.

Very preterm children at risk for developmental coordination disorder have brain alterations in motor areas.

AIM: Brain alterations in very preterm children at risk for developmental coordination disorder were investigated. METHODS: Infants born very preterm with gestation age <30 weeks or birthweight <1250 g were recruited from Royal Women's Hospital Melbourne from 2001 to 2003. Volumetric imaging was performed at term equivalent age; at seven years, volumetric imaging and diffusion tensor imaging were performed. At seven years, 53 of 162 children without cerebral palsy had scores ≤16th percentile on the Movement Assessment Battery for Children-Second Edition and were considered at risk for developmental coordination disorder. RESULTS: At term equivalent age, smaller brain volumes were found for total brain tissue, cortical grey matter, cerebellum, caudate accumbens, pallidum and thalamus in children at risk for developmental coordination disorder (p < 0.05); similar patterns were present at seven years. There was no evidence for catch-up brain growth in at-risk children. At seven years, at-risk children displayed altered microstructural organisation in many white matter tracts (p < 0.05). CONCLUSION: Infants born very preterm at risk for developmental coordination disorder displayed smaller brain volumes at term equivalent age and seven years, and altered white matter microstructure at seven years, particularly in motor areas. There was no catch-up growth from infancy to seven years.

Characterizing the Intraoperative Microelectrode Recording-Induced Microlesion Effect on Motor Symptoms in Patients with Parkinson's Disease Undergoing Deep Brain Stimulation of the Subthalamic Nucleus.

AIM: To investigate microelectrode recording (MER)-induced microlesion effect (MLE) on the motor symptoms of 30 patients with Parkinson’s disease (PD) who underwent deep brain stimulation of the subthalamic nucleus. MATERIAL AND METHODS: MER-induced MLE was evaluated based on the difference between tremor, rigidity, and bradykinesia scores in the preoperative off-state and intraoperative state following MER and before test stimulation. RESULTS: MLE scores improved by 21.7% [left (L) side] and by 13.6% [right (R) side] from baseline (p < 0.05). Tremor scores improved by 31.5% (L) and by 14.2% (R) (p < 0.05), rigidity scores improved by 17.3% (L) and by 14.2% (R) (p < 0.05) and bradykinesia scores improved by 20.6% (L) and by 11.5% (R) (p < 0.05) from baseline. There was no significant difference between MLE and the number of microelectrodes used (p > 0.05). CONCLUSION: MER-induced MLE improved motor symptoms and was not correlated with the number of microelectrodes used during the procedure.

Mirror neuron system activation in children with developmental coordination disorder: A replication functional MRI study.

BACKGROUND: It has been hypothesised that abnormal functioning of the mirror neuron system (MNS) may lead to deficits in imitation and the internal representation of movement, potentially contributing to the motor impairments associated with developmental coordination disorder (DCD). AIMS: Using fMRI, this study examined brain activation patterns in children with and without DCD on a finger adduction/abduction task during four MNS activation states: observation; motor imagery; execution; and imitation. METHODS AND PROCEDURES: Nineteen boys (8.25-12.75 years) participated, including 10 children with DCD (≤16th percentile on MABC-2; no ADHD/ASD), and nine typically developing controls (≥25th percentile on MABC-2). OUTCOMES AND RESULTS: Even though children with DCD displayed deficits behaviourally on imitation (Sensory Integration & Praxis Test Subtests) and motor imagery assessments prior to scanning, no differences in MNS activation were seen between the DCD and control groups at a neurological level, with both groups activating mirror regions effectively across conditions. Small clusters of decreased activation during imitation were identified in non-mirror regions in the DCD group, including the thalamus, caudate, and posterior cingulate - regions involved in motor planning and attentional processes. CONCLUSIONS AND IMPLICATIONS: The results of this study do not provide support for the MNS dysfunction theory as a possible causal mechanism for DCD. Further research to explore attentional and motor planning processes and how they may interact at a network level may enhance our understanding of this complex disorder.

White matter organization in developmental coordination disorder: A pilot study exploring the added value of constrained spherical deconvolution.

Previous studies of white matter organization in sensorimotor tracts in developmental coordination disorder (DCD) have adopted diffusion tensor imaging (DTI), a method unable to reconcile pathways with 'crossing fibres'. In response to limitations of the commonly adopted DTI approach, the present study employed a framework that can reconcile the 'crossing fibre' problem (i.e., constrained spherical deconvolution- CSD) to characterize white matter tissue organization of sensorimotor tracts in young adults with DCD. Participants were 19 healthy adults aged 18-46: 7 met diagnostic criteria for DCD (4 females) and 12 were controls (3 females). All underwent high angular diffusion MRI. After preprocessing, the left and right corticospinal tracts (CST) and superior longitudinal fasciculi (SLF) were delineated and all tracts were then generated using both CSD and DTI tractography respectively. Based on the CSD model, individuals with DCD demonstrated significantly decreased mean apparent fibre density (AFD) in the left SLF relative to controls (with large effect size, Cohen's d = 1.32) and a trend for decreased tract volume of the right SLF (with medium-large effect size, Cohen's d = 0.73). No differences in SLF microstructure were found between groups using DTI, nor were differences in CST microstructure observed across groups regardless of hemisphere or diffusion model. Our data are consistent with the view that motor impairment characteristic of DCD may be subserved by white matter abnormalities in sensorimotor tracts, specifically the left and right SLF. Our data further highlight the benefits of higher order diffusion MRI (e.g. CSD) relative to DTI for clarifying earlier inconsistencies in reports speaking to white matter organization in DCD, and its contribution to poor motor skill in DCD.

Prefrontal activation during Stroop and Wisconsin card sort tasks in children with developmental coordination disorder: a NIRS study.

We used near-infrared spectroscopy to examine dorsolateral prefrontal cortex (DLPFC) activation over time in 10 children with or at-risk-for developmental coordination disorder (DCD) and 11 typically developing children (ages 8-12) during tasks involving executive processing. The groups performed with similar accuracy on the Stroop and Wisconsin card sort (WCST), but their underlying neural activation differed. Typically developing children modulated DLPFC activity over time and showed rightward lateralization during Stroop but no lateralization during WCST. The DCD group exhibited high and sustained activation across hemispheres and tasks, which we suggest is a compensatory effort to maintain response accuracy.

Atlas-Independent, Electrophysiological Mapping of the Optimal Locus of Subthalamic Deep Brain Stimulation for the Motor Symptoms of Parkinson Disease.

BACKGROUND/AIMS: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves motor symptoms of Parkinson disease (PD). However, motor outcomes can be variable, perhaps due to inconsistent positioning of the active contact relative to an unknown optimal locus of stimulation. Here, we determine the optimal locus of STN stimulation in a geometrically unconstrained, mathematically precise, and atlas-independent manner, using Unified Parkinson Disease Rating Scale (UPDRS) motor outcomes and an electrophysiological neuronal stimulation model. METHODS: In 20 patients with PD, we mapped motor improvement to active electrode location, relative to the individual, directly MRI-visualized STN. Our analysis included a novel, unconstrained and computational electrical-field model of neuronal activation to estimate the optimal locus of DBS. RESULTS: We mapped the optimal locus to a tightly defined ovoid region 0.49 mm lateral, 0.88 mm posterior, and 2.63 mm dorsal to the anatomical midpoint of the STN. On average, this locus is 11.75 lateral, 1.84 mm posterior, and 1.08 mm ventral to the mid-commissural point. CONCLUSION: Our novel, atlas-independent method reveals a single, ovoid optimal locus of stimulation in STN DBS for PD. The methodology, here applied to UPDRS and PD, is generalizable to atlas-independent mapping of other motor and non-motor effects of DBS.

Developmental dysgraphia is often associated with minor neurological dysfunction in children with developmental coordination disorder (DCD).

OBJECTIVES: Children with developmental coordination disorder (DCD) are particularly affected by handwriting disorders, which remain poorly understood and are not clearly defined. The aim of our study is to provide a better understanding of handwriting disorders, and specifically of dysgraphia in children with DCD. METHODS: Sixty-five children with DCD (5-15 years), enrolled according to DSM-5, were assessed with handwriting testing and standardized assessments of neuropsychological, neurovisual, MRI and neuropsychomotor functions, with special attention paid to muscular tone examination. RESULTS: While handwriting disorders were strongly represented in our sample of children with DCD (89%), dysgraphia appeared uncommon (17%) and was closely related to several specific dysfunctions of laterality establishment; mild pyramidal tract dysfunction with distal phasic stretch reflex (PSR) in lower limbs; digital praxis slowness (both P<0.05). DISCUSSION: In our sample, dysgraphia was closely related to minor neurological dysfunction (MND) suggesting a disturbance of motor control at the level of the corticospinal motor pathway. This highlights the uncommon character of dysgraphia in children with DCD for which diagnosis should be made through a particular attention to evaluation of MND with muscular tone examination. This consideration, both in the research setting and in clinical practice, appears necessary to avoid inaccurate clinical diagnosis and to optimize appropriate therapeutic management.

Functional brain correlates of motor response inhibition in children with developmental coordination disorder and attention deficit/hyperactivity disorder.

Motor impairment is associated with developmental coordination disorder (DCD), and to a lesser extent with attention-deficit/hyperactivity disorder (ADHD). Previous functional imaging studies investigated children with DCD or ADHD only; however, these two disorders co-occur in up to 50% of cases, suggesting that similar neural correlates are associated with these disorders. This study compared functional brain activation in children and adolescents (age range 8-17, M = 11.73, SD = 2.88) with DCD (n = 9), ADHD (n = 20), co-occurring DCD and ADHD (n = 18) and typically developing (TD) controls (n = 20). When compared to TD controls, children with co-occurring DCD/ADHD showed decreased activation during response inhibition in primary motor and sensory cortices. These findings suggest that children with co-occurring DCD and ADHD display significant functional changes in brain activation that could interfere with inhibition of erroneous motor responses. In contrast to previous studies, significant alterations in brain activation relative to TD controls, were not found in children with isolated DCD or ADHD. These findings highlight the importance of considering co-occurring disorders when investigating brain function in children with neurodevelopmental disorders.

Grey-matter network disintegration as predictor of cognitive and motor function with aging.

Loss of grey-matter volume with advancing age affects the entire cortex. It has been suggested that atrophy occurs in a network-dependent manner with advancing age rather than in independent brain areas. The relationship between networks of structural covariance (SCN) disintegration and cognitive functioning during normal aging is not fully explored. We, therefore, aimed to (1) identify networks that lose GM integrity with advancing age, (2) investigate if age-related impairment of integrity in GM networks associates with cognitive function and decreasing fine motor skills (FMS), and (3) examine if GM disintegration is a mediator between age and cognition and FMS. T1-weighted scans of n = 257 participants (age range: 20-87) were used to identify GM networks using independent component analysis. Random forest analysis was implemented to examine the importance of network integrity as predictors of memory, executive functions, and FMS. The associations between GM disintegration, age and cognitive performance, and FMS were assessed using mediation analyses. Advancing age was associated with decreasing cognitive performance and FMS. Fourteen of 20 GM networks showed integrity changes with advancing age. Next to age and education, eight networks (fronto-parietal, fronto-occipital, temporal, limbic, secondary somatosensory, cuneal, sensorimotor network, and a cerebellar network) showed an association with cognition and FMS (up to 15.08%). GM networks partially mediated the effect between age and cognition and age and FMS. We confirm an age-related decline in cognitive functioning and FMS in non-demented community-dwelling subjects and showed that aging selectively affects the integrity of GM networks. The negative effect of age on cognition and FMS is associated with distinct GM networks and is partly mediated by their disintegration.

The validity of parental reports on motor skills performance level in preschool children: a comparison with a standardized motor test.

Motor skills are interrelated with essential domains of childhood such as cognitive and social development. Thus, the evaluation of motor skills and the identification of atypical or delayed motor development is crucial in pediatric practice (e.g., during well-child visits). Parental reports on motor skills may serve as possible indicators to decide whether further assessment of a child is necessary or not. We compared parental reports on fundamental motor skills performance level (e.g., hopping, throwing), based on questions frequently asked in pediatric practice, with a standardized motor test in 389 children (46.5% girls/53.5% boys, M age = 3.8 years, SD = 0.5, range 3.0-5.0 years) from the Swiss Preschoolers' Health Study (SPLASHY). Motor skills were examined using the Zurich Neuromotor Assessment 3-5 (ZNA3-5), and parents filled in an online questionnaire on fundamental motor skills performance level. The results showed that the answers from the parental report correlated only weakly with the objectively assessed motor skills (r = .225, p < .001). CONCLUSION: Although a parental screening instrument for motor skills would be desirable, the parent's report used in this study was not a valid indicator for children's fundamental motor skills. Thus, we may recommend to objectively examine motor skills in clinical practice and not to exclusively rely on parental report. What is Known: • Early assessment of motor skills in preschool children is important because motor skills are essential for the engagement in social activities and the development of cognitive abilities. Atypical or delayed motor development can be an indicator for different developmental needs or disorders. • Pediatricians frequently ask parents about the motor competences of their child during well-child visits. What is New: • The parental report on fundamental motor skills performance level used in this study was not a reliable indicator for describing motor development in the preschool age. • Standardized examinations of motor skills are required to validly assess motor development in preschoolers.