Measuring neuroplasticity associated with cerebral palsy rehabilitation: An MRI based power analysis

An exploratory study of functional brain activity associated with gross motor function improvement in children with unilateral cerebral palsy

PURPOSE

Identify relations of gross motor function and primary motor cortex (M1) functional activity pre and post gross motor interventions for children with unilateral cerebral palsy (UCP).

METHODS

Thirteen children with UCP completed a gross motor intervention. Pre/post-intervention functional MRI outcomes included the laterality index (LI), activation volume, and spatial overlap of M1 activation during active ankle dorsiflexion. Advanced gross motor function (Challenge) was assessed pre/post-intervention, and 2-6 months later. Bivariate correlations and linear regression assessed relations between neuroimaging and motor function.

RESULTS

Mean pre-intervention M1 activity was contralateral during dominant (LI =  +0.85, SD 0.21) but variable during the affected (LI =  +0.43, SD 0.57) ankle dorsiflexion. Changes in motor function and neuroimaging outcomes were not significantly associated. However, smaller affected ankle activation and less spatial overlap between ankle activations pre-intervention predicted Challenge improvements post-intervention (adjusted R2 = 0.74, p = .001.).

CONCLUSIONS

This exploratory study identified pre-intervention neuroimaging predictors of post-intervention improvements in advanced gross motor function.

Tractography of sensorimotor pathways in dyskinetic cerebral palsy: Association with motor function

OBJECTIVES

Neuroimaging studies of dyskinetic cerebral palsy (CP) are scarce and the neuropathological underpinnings are not fully understood. We delineated the corticospinal tract (CST) and cortico-striatal-thalamocortical (CSTC) pathways with probabilistic tractography to assess their (1) integrity and (2) association with motor functioning in people with dyskinetic CP.

METHODS

Diffusion weighted magnetic resonance images were obtained for 33 individuals with dyskinetic CP and 33 controls. Fractional anisotropy (FA) and mean diffusivity (MD) for the CST and the CSTC pathways were compared between groups. Correlation analyses were performed between tensor metric values and motor function scores of participants with dyskinetic CP as assessed by the Gross Motor Function Classification System (GMFCS), the Bimanual Fine Motor Function (BFMF), and the Manual Ability Classification System (MACS).

RESULTS

White matter integrity in both the CST and the CSTC pathways was reduced in people with dyskinetic CP. The GMFCS, MACS and, less commonly, the BFMF were associated with FA and, particularly, MD in most portions of these pathways.

INTERPRETATION

The present study advances our understanding of the involvement of white matter microstructure in sensorimotor pathways and its relationship with motor impairment in people with dyskinetic CP. Our results are consistent with well-described relationships between upper limb function and white matter integrity in the CST and CSTC pathways in other forms of CP. This knowledge may ultimately help prognosis and therapeutic programmes.

Neuroquantification enhances the radiological evaluation of term neonatal hypoxic-ischaemic cerebral injuries

Background

Injury patterns in hypoxic-ischaemic brain injury (HIBI) are well recognised but there are few studies evaluating cerebral injury using neuroquantification models.

Objectives

Quantification of brain volumes in a group of patients with clinically determined cerebral palsy.

Method

In this retrospective study, 297 children with cerebral palsy were imaged for suspected HIBI with analysis of various cerebral substrates. Of these, 96 children over the age of 3 years with a clinical diagnosis of cerebral palsy and abnormal MRI findings underwent volumetric analyses using the NeuroQuant® software solution. The spectrum of volumetric changes and the differences between the various subtypes (and individual subgroups) of HIBI were compared.

Results

Compared with the available normative NeuroQuant® database, the average intracranial volume was reduced to the 1st percentile in all patient groups (p < 0.001). Statistically significant differences were observed among the types and subgroups of HIBI. Further substrate volume reductions were identified and described involving the thalami, brainstem, hippocampi, putamina and amygdala. The combined volumes of five regions of interest (frontal pole, putamen, hippocampus, brainstem and paracentral lobule) were consistently reduced in the Rolandic basal ganglia-thalamus (RBGT) subtype.

Conclusion

This study determined a quantifiable reduction of intracranial volume in all subtypes of HIBI and predictable selective cerebral substrate volume reduction in subtypes and subgroups. In the RBGT subtype, a key combination of five substrate injuries was consistently noted, and thalamic, occipital lobe and brainstem volume reduction was also significant when compared to the watershed subtype.

Contribution

This study demonstrates the value of integrating an artificial intelligence programme into the radiologists' armamentarium serving to quantify brain injuries more accurately in HIBI. Going forward this will be an inevitable evolution of daily radiology practice in many fields of medicine, and it would be beneficial for radiologists to embrace these technological innovations.

Rehabilomics: A state-of-the-art review of framework, application, and future considerations

Rehabilomics is an important research framework that allows omics research built upon rehabilitation practice, especially in function evaluation, outcome prediction, and individualized rehabilitation. In the field of rehabilomics, biomarkers can serve as objectively measured indicators for body functioning, so as to complement the International Classification of Functioning, Disability, and Health (ICF) assessment. Studies on traumatic brain injury (TBI), stroke, and Parkinson's disease have shown that biomarkers (such as serum markers, MRI, and digital signals derived from sensors) are correlated with diagnosis, disease severity, and prognosis. Rehabilomics also examines a wide range of individual biological characteristics in order to develop personalized rehabilitation programs. Secondary prevention and rehabilitation of stroke have already adopted a rehabilomic approach to individualize treatment programs. Mechanisms of non-pharmacological therapies are expected to be unveiled in light of rehabilomics research. When formulating the research plan, learning from established databases is recommended and a multidisciplinary collaborative team is warranted. Although still in its infancy, the advancement and incorporation of rehabilomics has the potential to make a significant impact on public health.

Functional Neuroplasticity and Motor Skill Change Following Gross Motor Interventions for Children With Diplegic Cerebral Palsy

BACKGROUND

Gross motor intervention designs for children with diplegic cerebral palsy (DCP) require an improved understanding of the children's potential for neuroplasticity.

OBJECTIVE

To identify relations between functional neuroplasticity and motor skill changes following gross motor interventions for children with DCP.

METHODS

There were 17 participants with DCP (ages 8-16 years; 6 females; Gross Motor Function Classification System Level I [n = 9] and II [n = 8]). Each completed a 6-week gross motor intervention program that was directed toward achievement of individualized motor/physical activity goals. Outcomes were assessed pre/post and 4 to 6 months post-intervention (follow-up). An active ankle dorsiflexion task was completed during functional magnetic resonance imaging. The ratio of motor cortical activation volume in each hemisphere was calculated using a laterality index. The Challenge was the primary gross motor skill measure. Change over time and relations among outcomes were evaluated.

RESULTS

Challenge scores improved post-intervention (4.57% points [SD 4.45], P = .004) and were maintained at follow-up (0.75% [SD 6.57], P = 1.000). The laterality index for dominant ankle dorsiflexion increased (P = .033), while non-dominant change was variable (P = .534). Contralateral activation (laterality index ≥+0.75) was most common for both ankles. Challenge improvements correlated with increased ipsilateral activity (negative laterality index) during non-dominant dorsiflexion (r = -.56, P = .045). Smaller activation volume during non-dominant dorsiflexion predicted continued gross motor gains at follow-up (R² = .30, P = .040).

CONCLUSIONS

Motor cortical activation during non-dominant ankle dorsiflexion is a modest indicator of the potential for gross motor skill change. Further investigation of patterns of neuroplastic change will improve our understanding of effects.

CLINICALTRIALS.GOV REGISTRY

NCT02584491 and NCT02754128.

Efficacy of early interventions with active parent implementation in low-and-Middle income countries for young children with cerebral palsy to improve child development and parent mental health outcomes: a systematic review

PURPOSE

To determine the efficacy of interventions with active parent implementation for young children with cerebral palsy (CP) to improve child and parent outcomes in low-middle income countries (LMICs).

METHODS

Five databases were systematically searched. Randomised or comparison studies evaluating interventions with the training of the parent and/or home practice components to implement with their child with CP (<60 months of age) were included. The modified Downs and Black scale assessed methodological quality. Data were pooled to calculate mean differences and 95% confidence intervals (95% CI).

RESULTS

Searches yielded 189 unique articles. 11 studies from ten papers of moderate to high quality were included. Parent-implemented general developmental interventions had a small negative effect on gross motor function compared to interventionist-implemented therapy. Parent-implemented upper limb training compared to interventionist-implemented neurodevelopmental therapy had a small positive effect on bimanual hand function. Parent-implemented functional feeding training had a large significant effect on chewing function compared to parent-implemented oral motor exercises. Parent-implemented interventions targeting general child development and feeding had mixed effects on parent stress outcomes.

CONCLUSIONS

Parent-implemented interventions in LMICs are promising to improve child bimanual hand and chewing function. Further research evaluating the efficacy of parent-implemented interventions to improve parent mental health is needed.Implications for Rehabilitation:Intensive motor training-based interventions with active parent implementation were effective to improve child gross motor, bimanual hand, and chewing function in young children with CP compared to passive, generic interventionist-implemented or health education interventions.Interventions with active parent implementation had mixed results to improve parent mental health, however, this was frequently not assessed. A consistent level of support and training provided to parents may be required to have a positive effect on parent stress.To further understand the feasibility of early interventions with active parent implementation in LMICs, data on adherence to home practice dose and session attendance and a qualitative understanding of contextual and child factors influencing parent implementation is needed.

Avoiding data loss: Synthetic MRIs generated from diffusion imaging can replace corrupted structural acquisitions for freesurfer-seeded tractography

Magnetic Resonance Imaging (MRI) motion artefacts frequently complicate structural and diffusion MRI analyses. While diffusion imaging is easily ‘scrubbed’ of motion affected volumes, the same is not true for T1w or T2w ‘structural’ images. Structural images are critical to most diffusion-imaging pipelines thus their corruption can lead to disproportionate data loss. To enable diffusion-image processing when structural images are missing or have been corrupted, we propose a means by which synthetic structural images can be generated from diffusion MRI. This technique combines multi-tissue constrained spherical deconvolution, which is central to many existing diffusion analyses, with the Bloch equations that allow simulation of MRI intensities for given scanner parameters and magnetic resonance (MR) tissue properties. We applied this technique to 32 scans, including those acquired on different scanners, with different protocols and with pathology present. The resulting synthetic T1w and T2w images were visually convincing and exhibited similar tissue contrast to acquired structural images. These were also of sufficient quality to drive a Freesurfer-based tractographic analysis. In this analysis, probabilistic tractography connecting the thalamus to the primary sensorimotor cortex was delineated with Freesurfer, using either real or synthetic structural images. Tractography for real and synthetic conditions was largely identical in terms of both voxels encountered (Dice 0.88–0.95) and mean fractional anisotropy (intrasubject absolute difference 0.00–0.02). We provide executables for the proposed technique in the hope that these may aid the community in analysing datasets where structural image corruption is common, such as studies of children or cognitively impaired persons.

A methodological scoping review of the integration of fMRI to guide dMRI tractography. What has been done and what can be improved: A 20-year perspective

Combining MRI modalities is a growing trend in neurosciences. It provides opportunities to investigate the brain architecture supporting cognitive functions. Integrating fMRI activation to guide dMRI tractography offers potential advantages over standard tractography methods. A quick glimpse of the literature on this topic reveals that this technique is challenging, and no consensus or "best practices" currently exist, at least not within a single document. We present the first attempt to systematically analyze and summarize the literature of 80 studies that integrated task-based fMRI results to guide tractography, over the last two decades. We report 19 findings that cover challenges related to sample size, microstructure modelling, seeding methods, multimodal space registration, false negatives/positives, specificity/validity, gray/white matter interface and more. These findings will help the scientific community (1) understand the strengths and limitations of the approaches, (2) design studies using this integrative framework, and (3) motivate researchers to fill the gaps identified. We provide references toward best practices, in order to improve the overall result's replicability, sensitivity, specificity, and validity.

Perinatal stroke: mapping and modulating developmental plasticity

Most cases of hemiparetic cerebral palsy are caused by perinatal stroke, resulting in lifelong disability for millions of people. However, our understanding of how the motor system develops following such early unilateral brain injury is increasing. Tools such as neuroimaging and brain stimulation are generating informed maps of the unique motor networks that emerge following perinatal stroke. As a focal injury of defined timing in an otherwise healthy brain, perinatal stroke represents an ideal human model of developmental plasticity. Here, we provide an introduction to perinatal stroke epidemiology and outcomes, before reviewing models of developmental plasticity after perinatal stroke. We then examine existing therapeutic approaches, including constraint, bimanual and other occupational therapies, and their potential synergy with non-invasive neurostimulation. We end by discussing the promise of exciting new therapies, including novel neurostimulation, brain-computer interfaces and robotics, all focused on improving outcomes after perinatal stroke.

Training-Induced Neural Plasticity in Youth: A Systematic Review of Structural and Functional MRI Studies

Experience-dependent neural plasticity is high in the developing brain, presenting a unique window of opportunity for training. To optimize existing training programs and develop new interventions, it is important to understand what processes take place in the developing brain during training. Here, we systematically review MRI-based evidence of training-induced neural plasticity in children and adolescents. A total of 71 articles were included in the review. Significant changes in brain activation, structure, microstructure, and structural and functional connectivity were reported with different types of trainings in the majority (87%) of the studies. Significant correlation of performance improvement with neural changes was reported in 51% of the studies. Yet, only 48% of the studies had a control condition. Overall, the review supports the hypothesized neural changes with training while at the same time charting empirical and methodological desiderata for future research.

Cortical thickness of primary visual cortex correlates with motion deficits in periventricular leukomalacia

Impairments of visual motion perception and, in particular, of flow motion have been consistently observed in premature and very low birth weight subjects during infancy. Flow motion information is analyzed at various cortical levels along the dorsal pathways, with information mainly provided by primary and early visual cortex (V1, V2 and V3). We investigated the cortical stage of the visual processing that underlies these motion impairments, measuring Grey Matter Volume and Cortical Thickness in 13 children with Periventricular Leukomalacia (PVL). The cortical thickness, but not the grey matter volume of area V1, correlates negatively with motion coherence sensitivity, indicating that the thinner the cortex, the better the performance among the patients. However, we did not find any such association with either the thickness or volume of area MT, MST and areas of the IPS, suggesting damage at the level of primary visual cortex or along the optic radiation.

Prediction of childhood brain outcomes in infants born preterm using neonatal MRI and concurrent clinical biomarkers (PREBO-6): study protocol for a prospective cohort study

INTRODUCTION

Infants born very preterm are at risk of adverse neurodevelopmental outcomes, including cognitive deficits, motor impairments and cerebral palsy. Earlier identification enables targeted early interventions to be implemented with the aim of improving outcomes.

METHODS AND ANALYSIS

Protocol for 6-year follow-up of two cohorts of infants born <31 weeks gestational age (PPREMO: Prediction of Preterm Motor Outcomes; PREBO: Prediction of Preterm Brain Outcomes) and a small term-born reference sample in Brisbane, Australia. Both preterm cohorts underwent very early MRI and concurrent clinical assessment at 32 and 40 weeks postmenstrual age (PMA) and were followed up at 3, 12 and 24 months corrected age (CA). This study will perform MRI and electroencephalography (EEG). Primary outcomes include the Movement Assessment Battery for Children second edition and Full-Scale IQ score from the Wechsler Intelligence Scale for Children fifth edition (WISC-V). Secondary outcomes include the Gross Motor Function Classification System for children with cerebral palsy; executive function (Behavior Rating Inventory of Executive Function second edition, WISC-V Digit Span and Picture Span, Wisconsin Card Sorting Test 64 Card Version); attention (Test of Everyday Attention for Children second edition); language (Clinical Evaluation of Language Fundamentals fifth edition), academic achievement (Woodcock Johnson IV Tests of Achievement); mental health and quality of life (Development and Well-Being Assessment, Autism Spectrum Quotient-10 Items Child version and Child Health Utility-9D).

AIMS

Examine the ability of early neonatal MRI, EEG and concurrent clinical measures at 32 weeks PMA to predict motor, cognitive, language, academic achievement and mental health outcomes at 6 years CA.Determine if early brain abnormalities persist and are evident on brain MRI at 6 years CA and the relationship to EEG and concurrent motor, cognitive, language, academic achievement and mental health outcomes.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from Human Research Ethics Committees at Children's Health Queensland (HREC/19/QCHQ/49800) and The University of Queensland (2019000426). Study findings will be presented at national and international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12619000155190p. WEB ADDRESS OF TRIAL: http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12619000155190p.

Study protocol of a randomized controlled trial of home-based computerized executive function training for children with cerebral palsy

BACKGROUND

Cerebral palsy (CP) is frequently associated with specific cognitive impairments, such as executive dysfunction which are related to participation and quality of life (QOL). The proposed study will examine whether a computerized executive function (EF) training programme could provide superior benefits for executive functioning, participation, QOL and brain plasticity, as compared to usual care.

METHODS

A single-blind randomized controlled trial (RCT) design will be performed. Thirty children with CP aged 8 to 12 years will participate in a home-based computerized multi-modal executive training programme (12 weeks, 5 days a week, 30 min a day training, total dose = 30 h). Thirty children with CP matched by age, sex, motor and intelligence quotient (IQ) will compose the waitlist group. Cognitive, behavioural, emotional, participation and QOL measures will be obtained at three time points: before, immediately after and 9 months after completing the training. Additionally, structural and functional (resting state) magnetic resonance images (MRI) will be obtained in a subsample of 15 children from each group. Outcomes between groups will be compared following standard principles for RCTs.

DISCUSSION

The study will test whether the cognitive training programme exerts a positive effect not only on neuropsychological and daily functioning of children with CP but also on other measures such as participation and QOL. We will also use brain MRI to test brain functional and structural changes after the intervention. If this on-line and home-based training programme proves effective, it could be a cost-effective intervention with short- and long-term effects on EF, participation or QOL in CP.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04025749. Registered 19 July 2019. Retrospectively registered.

Influence of adapted hip-hop dancing on quality of life and social participation among children/adolescents with cerebral palsy

OBJECTIVE

To describe the influence of adapted hip-hop dancing on the quality of life (QoL) and biopsychosocial profile of children/adolescents with cerebral palsy (CP).

METHODS

Pilot study including 18 children/adolescents with CP and Gross Motor Function Classification System levels I and II. Nine participants took part in an adapted hip-hop dance practice (study group; SG), and nine others served as the control group (CG). All participants were assessed with the Pediatric Outcomes Data Collection Instrument and the Child Behavior Checklist at baseline and after at least three months of dance practice and a public performance (SG) or a similar period without intervention (CG).

RESULTS

Improvement in QoL was observed in the SG in the domains of transfer and basic mobility (p = 0.00*), sporting and physical function (p = 0.04*), and global function and symptoms (p = 0.01*). In the SG, there was a reduction in emotional and behavioral problems and an increase in social competence in the biopsychosocial profile. Greater participation in adapted hip-hop dancing was associated with a greater gain in the transfer and basic mobility domains (p = 0.05*) of the Pediatric Outcomes Data Collection Instrument and in the activities (p = 0.05*) and social (p = 0.04*) scales of the Child Behavior Checklist.

CONCLUSIONS

Children/adolescents with CP participating in adapted hip-hop dance practice showed improvement in QoL and biopsychosocial profile scores.

Protocol for a multisite randomised trial of Hand-Arm Bimanual Intensive Training Including Lower Extremity training for children with bilateral cerebral palsy: HABIT-ILE Australia

INTRODUCTION

Children with bilateral cerebral palsy often experience difficulties with posture, gross motor function and manual ability, impacting independence in daily life activities, participation and quality of life (QOL). Hand-Arm Bimanual Intensive Training Including Lower Extremity (HABIT-ILE) is a novel intensive motor intervention integrating upper and lower extremity training. This study aimed to compare HABIT-ILE to usual care in a large randomised controlled trial (RCT) in terms of gross motor function, manual ability, goal attainment, walking endurance, mobility, self-care and QOL. A within-trial cost-utility analysis will be conducted to synthesise costs and benefits of HABIT-ILE compared with usual care.

METHODS AND ANALYSIS

126 children with bilateral cerebral palsy aged 6-16 years will be recruited across three sites in Australia. Children will be stratified by site and Gross Motor Function Classification System and randomised using concealed allocation to either receiving HABIT-ILE immediately or being waitlisted for 26 weeks. HABIT-ILE will be delivered in groups of 8-12 children, for 6.5 hours per day for 10 days (total 65 hours, 2 weeks). Outcomes will be assessed at baseline, immediately following intervention, and then retention of effects will be tested at 26 weeks. Primary outcomes will be the Gross Motor Function Measure and ABILHAND-Kids. Secondary outcomes will be brain structural integrity, walking endurance, bimanual hand performance, self-care, mobility, performance and satisfaction with individualised goals, and QOL. Analyses will follow standard principles for RCTs using two-group comparisons on all participants on an intention-to-treat basis. Comparisons between groups for primary and secondary outcomes will be conducted using regression models.

ETHICS AND DISSEMINATION

Ethics approval has been granted by the Medical Research Ethics Committee of Children's Health Queensland Hospital and the Health Service Human Research Ethics Committee (HREC/17/QRCH/282) of The University of Queensland (2018000017/HREC/17/QRCH/2820), and The Cerebral Palsy Alliance Ethics Committee (2018_04_01/HREC/17/QRCH/282).

TRIAL REGISTRATION NUMBER

ACTRN12618000164291.

Neurite orientation dispersion and density imaging quantifies corticospinal tract microstructural organization in children with unilateral cerebral palsy

Children with unilateral cerebral palsy (UCP) due to early brain injury exhibit disrupted connectivity of corticospinal tracts (CSTs), which can be quantified using diffusion-weighted magnetic resonance imaging (DWI). Diffusion tensor imaging (DTI) is commonly used to quantify white matter organization, however, this model lacks the biological specificity to accurately describe underlying microstructural properties. Newer approaches, such as neurite orientation dispersion and density imaging (NODDI), may provide more biologically accurate information regarding CST microstructure. In this study, we directly compared metrics of CST microstructure using NODDI and DTI models to characterize the microstructural organization of corticospinal pathways. Twenty participants with UCP participating in a neuromodulation/rehabilitation intervention underwent imaging including multi-shell DWI; 10 participants' datasets were adequately completed for neuroimaging analysis. Task fMRI-guided probabilistic tractography from motor cortex to brainstem was performed at baseline and follow-up to reconstruct the CSTs. Diffusion metrics were compared between hemispheres at baseline, and between baseline and follow-up to test for intervention effects. Correlation analyses were used to compare baseline metrics to changes in hand function following the intervention. DTI results showed that mean fractional anisotropy in lesioned and nonlesioned CSTs did not significantly differ, but mean, axial, and radial diffusivity were greater in the lesioned CST. For NODDI, intracellular volume fraction (ICVF) and orientation dispersion index (ODI) were lower in the lesioned CST. Unimanual function was strongly correlated with ICVF, but not FA. NODDI may reveal distinct properties of CST microstructure that are linked to motor function, indicating their potential in characterizing brain structure and development.

Devices and Protocols for Upper Limb Robot-Assisted Rehabilitation of Children with Neuromotor Disorders

Neuromotor disorders negatively affect the sensorimotor system, limiting the ability to perform daily activities autonomously. Rehabilitation of upper limb impairments is therefore essential to improve independence and quality of life. In the last two decades, there has been a growing interest in robot-assisted rehabilitation as a beneficial way to promote children recovery process. However, a common understanding of the best drivers of an effective intervention has not been reached yet. With this aim, the current study reviewed the existing literature on robot-assisted rehabilitation protocols for upper extremities in children, with the goal of examining the effects of robotic therapy on their sensorimotor recovery process. A literature search was conducted in several electronic database to identify the studies related to the application of robotic therapy on upper limbs in the pediatric population. We analyzed three reviews and 35 studies that used 14 different robotic devices, and an overview of their characteristics, applications in the clinical setting and results is provided. Besides, the potential benefits of robot-assisted assessment and therapy are discussed to identify the key factors yielding positive outcomes in children. Finally, this review aim to lay the foundations for more effective neuroplasticity-enhancement protocols and elicit insights into robot-based approaches.

Emergent Prophylactic, Reparative and Restorative Brain Interventions for Infants Born Preterm With Cerebral Palsy

Worldwide, an estimated 15 million babies are born preterm (<37 weeks' gestation) every year. Despite significant improvements in survival rates, preterm infants often face a lifetime of neurodevelopmental disability including cognitive, behavioral, and motor impairments. Indeed, prematurity remains the largest risk factor for the development of cerebral palsy. The developing brain of the preterm infant is particularly fragile; preterm babies exhibit varying severities of cerebral palsy arising from reductions in both cerebral white and gray matter volumes, as well as altered brain microstructure and connectivity. Current intensive care therapies aim to optimize cardiovascular and respiratory function to protect the brain from injury by preserving oxygenation and blood flow. If a brain injury does occur, definitive diagnosis of cerebral palsy in the first few hours and weeks of life is difficult, especially when the lesions are subtle and not apparent on cranial ultrasound. However, early diagnosis of mildly affected infants is critical, because these are the patients most likely to respond to emergent treatments inducing neuroplasticity via high-intensity motor training programs and regenerative therapies involving stem cells. A current controversy is whether to test universal treatment in all infants at risk of brain injury, accepting that some patients never required treatment, because the perceived potential benefits outweigh the risk of harm. Versus, waiting for a diagnosis before commencing targeted treatment for infants with a brain injury, and potentially missing the therapeutic window. In this review, we discuss the emerging prophylactic, reparative, and restorative brain interventions for infants born preterm, who are at high risk of developing cerebral palsy. We examine the current evidence, considering the timing of the intervention with relation to the proposed mechanism/s of action. Finally, we consider the development of novel markers of preterm brain injury, which will undoubtedly lead to improved diagnostic and prognostic capability, and more accurate instruments to assess the efficacy of emerging interventions for this most vulnerable group of infants.

Rehabilitation-induced brain changes detected through magnetic resonance imaging in children with neurodevelopmental disorders: A systematic review

AIM

The aim of this study was to systematically review evidence about rehabilitation-induced neuroplasticity measured by magnetic resonance imaging (MRI) in children with neurodevelopmental disorders.

METHOD

The following databases were searched: MEDLINE, EMBASE, CINAHL, and PsycINFO. Two independent reviewers screened articles according to inclusion criteria: (1) peer-review study published in a scientific journal; (2) studies that evaluated a rehabilitation-based intervention; (3) participants aged less than 19 years with a neurodevelopmental disorder; and (4) studies that used at least one MRI modality as an outcome measure. Twenty-seven studies met the criteria for the review and their quality was assessed by two independent reviewers using the Effective Public Health Practice Project Quality Assessment Tool.

RESULTS

Based on an assessment of bias and overall quality, 11% of the papers were rated as strong; 30% moderate; and 59% weak. Outcomes were categorized into structural connectivity, functional connectivity, cortical activation, and structural volume. Cortical activation and structural connectivity were the most commonly reported measures. Most studies were able to identify brain changes in children with neurodevelopmental disorders after therapy.

INTERPRETATIONS

Rehabilitation is shown to induce MRI-detectable neuroplastic changes in children with neurodevelopmental disorders. Structural connectivity might need greater intensity and/or duration of intervention to induce change.

Optimization of fMRI methods to determine laterality of cortical activation during ankle movements of children with unilateral cerebral palsy

Measurement of laterality of motor cortical activations may provide valuable information about lower limb control in children with unilateral cerebral palsy (UCP). Evidence from upper limb research suggests that increased contralateral activity may accompany functional gains. However, lower limb areas of activation and associated changes have been underexplored due to challenges with imaging motor cortical leg representations. In this study, methods for a task-based functional magnetic resonance imaging (fMRI) ankle dorsiflexion paradigm were refined with three pilot groups of participants: (i) adults (n = 5); (ii) typically developing (TD) children (n = 5) and; (iii) children with UCP (n = 4). Parameters of experimental design, task resistance, reproducibility, and pre-scan procedures were tested/refined using a staged development approach with additions or changes introduced if image quality did not meet pre-defined standards. When image quality was acceptable for two consecutive participants, the next participant group was recruited to test/refine the next parameter. The final paradigm involved an event-related design of a single dorsiflexion movement against individualized resistance, with two runs per leg. It included a pre-scan session to increase child comfort and determine task resistance. This paradigm produced valid data for laterality index (LI) calculations to determine the ratio of activity in each hemisphere. Ventricle and lesion masks were used in non-linear image registration, and individual thresholds were used for extent-based LI calculations. LI of dominant ankle movements were contralateral (LI ≥ +0.2) for TD children (mean LI = +0.89, std = 0.27) and children with UCP (mean LI = +0.86, std = 0.26). For the affected ankle of children with UCP, LI values indicated ipsilateral and/or contralateral activation (mean LI = +0.02, std = 0.71, range -0.92 to +1.00). This fMRI paradigm will support investigations of cortical activation and mechanisms of skill improvement following lower limb interventions.