Hand function assessment in the first years of life in unilateral cerebral palsy: Correlation with neuroimaging and cortico-spinal reorganization

Development and validation of a novel model based on hand knob score and white matter injury on MRI to predict hand function in children with cerebral palsy

BACKGROUND

Childhood hand function is considered to be one of the strongest predictors of the ability to participate in daily activities as children with cerebral palsy (CP) reach adulthood. The manual ability classification system (MACS) is currently the most widely used for grading hand function in children with CP. However, the MACS method is subjective and may be affected by the raters' experience. Hand knob is an important control center for hand movement. Therefor this study aimed to develop and validate an objective model for hand function estimation in children with CP and visualize it as a nomogram.

METHODS

A total of 70 Children (2-12 years old) with CP underwent magnetic resonance imaging (MRI) scanning, MACS assessment. According to MACS, children with CP were divided into mild impairment group (grade I-III) and severe impairment group (grade IV-V). Hand function prediction models based on (I) hand knob score, (II) clinical features, and (III) the combination of clinical features and hand knob score were developed and validated separately. The models were subjected to stepwise regression according to the maximum likelihood method, and the Akaike information criterion was used to select the best model. Model discrimination was assessed using receiver operating characteristic (ROC) and calibration curves. The nomogram was finally built according to the best model.

RESULTS

The area under the curve (AUC) of the hand knob score model in the training set was 0.752, the clinical features model was 0.819, and the hand knob score and clinical features combined model was 0.880. The AUC of the hand knob score model in the validation set was 0.765, the clinical features model was 0.782, and the combined model was 0.894. The best model was the hand knob score-clinical features combined model, and the nomogram finally incorporated two assessment items: the hand knob score and white matter injury. The estimated probability of hand function injury degree of the combined model displayed good agreement with the actual occurrence probability.

CONCLUSIONS

The hand knob score-clinical features combined model can be used to preliminarily assess the degree of hand impairment in children with CP, with good calibration.

Motor planning is not restricted to only one hemisphere: evidence from ERPs in individuals with hemiplegic cerebral palsy

The evidence for the hemispheric specialization of motor planning reveals several inconsistencies between the left-lateralized hypothesis and a distributed system across the hemispheres. We compared participants with left hemiplegic cerebral palsy (HCP) to right-handed control subjects in this study's first experiment by inviting them to perform a motor planning task. Participants were required to release the start button, grasp a hexagon, and rotate it according to the instructions. In the second experiment, we compared left-HCP subjects with right-HCP subjects inviting them to perform the same task (we used the data for left-HCP subjects from the first experiment). P2 amplitude, as well as planning time, grasping time, releasing time, and initial grip selection planning patterns, were used as outcome measures in both experiments. The first experiment revealed that controls acted more quickly and chose more effective planning patterns. Also, the P2 amplitude was smaller in left-HCP subjects than in control subjects. No significant group effect was observed in the second experiment for any movement-related measure or P2. At the neural level, however, there was an interaction between 'region' and 'group,' indicating the distinction between the two groups in the right region. The results are discussed in terms of motor planning's hemispheric distribution and individual differences in the HCP group.

Hand function development of children with hemiplegic cerebral palsy: A scoping review

PURPOSE

Hemiplegic cerebral palsy (hCP) typically impacts sensorimotor control of the hand, but comprehensive assessments of the hands of children with hCP are relatively rare. This scoping review summarizes the development of hand function for children with hCP.

METHODS

This scoping review focused on the development of hand function in children with hCP. Electronic databases (PubMed, PEDro, Web of Science, CINAHL, and SpringerLink) were searched to identify studies assessing hand function in children with hCP. The search was performed using keywords (e.g., "hemiplegia"). An iterative approach verified by two authors was used to select the studies. Articles which reported quantitative data for children with hCP on any items of a specified set of hand evaluations were included. Measures were sorted into three categories: quantitative neuromechanics, clinical assessments, and clinical functional evaluations.

RESULTS

Initial searches returned 1536 articles, 131 of which were included in the final review. Trends between assessment scores and age were examined for both hands.

CONCLUSION

While several studies have evaluated hand function in children with hCP, the majority relied on clinical scales, assessments, or qualitative descriptions. Further assessments of kinematics, kinetics, and muscle activation patterns are needed to identify the underlying impairment mechanisms that should be targeted for treatment.

Motor learning in unilateral cerebral palsy and the influence of corticospinal tract reorganization

Cerebral Palsy (CP) is a complex neurological disorder, characterized by congenital motor disability associated with behaviour, perception and cognition disorders. The sensorimotor impairments represent the main hallmark of the disease, significantly impacting the quality of life. So far, few studies have investigated motor learning abilities in CP and their association with the plastic reorganization of the motor system remains largely unknown. The present proof-of-principle study explored explicit motor sequence learning in children with unilateral CP and different patterns of motor system reorganization (bilateral, ipsilateral, contralateral). Children with unilateral CP, and a group of age-matched typically developing (TD) children, underwent a sequential finger tapping task, performed with the affected hand by children with CP and with the non-dominant hand by TD children. The pattern of corticospinal tract projections in hemiparetic patients was assessed by single-pulse Transcranial Magnetic Stimulation (TMS). Results showed the presence of finger dexterity impairments in children with unilateral CP presenting with a bilateral or an ipsilateral control of the affected (trained) hand, as compared to TD children. Conversely, motor sequence learning was impaired in unilateral CP with ipsilateral or contralateral corticospinal reorganization, but not in the case of a bilateral control of the paretic hand. These preliminary findings, although referred to small clinical samples, suggest that unilateral control of the paretic upper-limb, from the ipsilateral or the contralateral motor cortex, may not be sufficient to develop typical motor learning with the affected hand, which seems to require a bilateral representation in the motor cortex. This evidence has potential implications for fine motor skills rehabilitation in CP.

The relationship between neuroimaging and motor outcome in children with cerebral palsy: A systematic review - Part A. Structural imaging

BACKGROUND

Conventional Structural Magnetic Resonance Imaging (sMRI) is a mainstay in Cerebral Palsy (CP) diagnosis.

AIMS

A systematic literature review was performed with the aim to investigate the relationship between structural brain lesions identified by sMRI and motor outcomes in children with CP.

METHODS

Fifty-eight studies were included. The results were analysed in terms of population characteristics, sMRI (classified according to Krägeloh-Mann & Horber, 2007), gross and fine motor function and their interrelation.

OUTCOMES

White matter lesions were the most common brain lesion types and were present in 57.8 % of all children with uCP, in 67.0 % of all children with bCP and in 33 % of the group of mixed subtypes. Grey matter lesions were most frequently registered in children with dyskinesia (n = 42.2 %). No structural anomalies visualized by sMRI were reported in 5.7 % of all cases. In all lesion types, an equal distribution over the different gross motor function classification system categories was present. The included studies did not report sufficient information about fine motor function to relate these results to structural imaging.

CONCLUSIONS AND IMPLICATIONS

The relationship between brain structure and motor outcome needs to be further elucidated in a representative cohort of children with CP, using a more standardized MRI classification system.

PredictMed: A logistic regression-based model to predict health conditions in cerebral palsy

Logistic regression-based predictive models are widely used in the healthcare field but just recently are used to predict comorbidities in children with cerebral palsy. This article presents a logistic regression approach to predict health conditions in children with cerebral palsy and a few examples from recent research. The model named PredictMed was trained, tested, and validated for predicting the development of scoliosis, intellectual disabilities, autistic features, and in the present study, feeding disorders needing gastrostomy. This was a multinational, cross-sectional descriptive study. Data of 130 children (aged 12-18 years) with cerebral palsy were collected between June 2005 and June 2015. The logistic regression-based model uses an algorithm implemented in R programming language. After splitting the patients in training and testing sets, logistic regressions are performed on every possible subset (tuple) of independent variables. The tuple that shows the best predictive performance in terms of accuracy, sensitivity, and specificity is chosen as a set of independent variables in another logistic regression to calculate the probability to develop the specific health condition (e.g. the need for gastrostomy). The average of accuracy, sensitivity, and specificity score was 90%. Our model represents a novelty in the field of some cerebral palsy-related health outcomes treatment, and it should significantly help doctors' decision-making process regarding patient prognosis.

A Platform for Rehabilitation of Finger Individuation in Children with Hemiplegic Cerebral Palsy

The brain injury that results in cerebral palsy CP may adversely affect fine motor control of the hand. The degradation of manual dexterity in the fingers profoundly impacts overall functionality of the upper limb, yet research efforts to facilitate rehabilitation of finger individuation in children with CP have been limited. This study describes the development of an integrated hardware and software platform for training and evaluating finger individuation. A pneumatically actuated glove provides extension assistance or flexion resistance independently to each digit in concert with playing a virtual reality keyboard. This setup enables intensive and efficient practice of fine motor control of either or both hands. Bimanual training options range from mirror movements to fully independent motions and rhythms in each hand, thereby enabling maintenance of the proper level of challenge. Additionally, an instrument was created to provide assessment of individuated fingertip force generation in order to evaluate effectiveness of the training. Preliminary data were obtained from children both with and without CP using this tool.

Motor Evoked Potentials as Potential Biomarkers of Early Atypical Corticospinal Tract Development in Infants with Perinatal Stroke

Diagnosis of cerebral palsy (CP) after perinatal stroke is often delayed beyond infancy, a period of rapid neuromotor development with heightened potential for rehabilitation. This study sought to assess whether the presence or absence of motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) could be an early biomarker of atypical development within the first year of life. In 10 infants with perinatal stroke, motor outcome was assessed with a standardized movement assessment. Single-pulse TMS was utilized to assess presence of MEPs. Younger infants (3-6 months CA, n = 5, 4/5 (80%)) were more likely to present with an MEP from the more-affected hemisphere (MAH) compared to older infants (7-12 months CA, n = 5, 0/5, (0%)) (p = 0.048). Atypical movement was demonstrated in the majority of infants with an absent MEP from the MAH (5/6, 83%) compared to those with a present MEP (1/4, 25%) (p = 0.191). We found that age influences the ability to elicit an MEP from the MAH, and motor outcome may be related to MAH MEP absence. Assessment of MEPs in conjunction with current practice of neuroimaging and motor assessments could promote early detection and intervention in infants at risk of CP.

Non-Invasive Brain Stimulation in Children With Unilateral Cerebral Palsy: A Protocol and Risk Mitigation Guide

Non-invasive brain stimulation has been increasingly investigated, mainly in adults, with the aims of influencing motor recovery after stroke. However, a consensus on safety and optimal study design has not been established in pediatrics. The low incidence of reported major adverse events in adults with and without clinical conditions has expedited the exploration of NIBS in children with paralleled purposes to influence motor skill development after neurological injury. Considering developmental variability in children, with or without a neurologic diagnosis, adult dosing and protocols may not be appropriate. The purpose of this paper is to present recommendations and tools for the prevention and mitigation of adverse events (AEs) during NIBS in children with unilateral cerebral palsy (UCP). Our recommendations provide a framework for pediatric NIBS study design. The key components of this report on NIBS AEs are (a) a summary of related literature to provide the background evidence and (b) tools for anticipating and managing AEs from four international pediatric laboratories. These recommendations provide a preliminary guide for the assessment of safety and risk mitigation of NIBS in children with UCP. Consistent reporting of safety, feasibility, and tolerability will refine NIBS practice guidelines contributing to future clinical translations of NIBS.

Structural Brain Damage and Upper Limb Kinematics in Children with Unilateral Cerebral Palsy

Background: In children with unilateral cerebral palsy (uCP) virtually nothing is known on the relation between structural brain damage and upper limb (UL) kinematics quantified with three-dimensional movement analysis (3DMA). This explorative study aimed to (1) investigate differences in UL kinematics between children with different lesion timings, i.e., periventricular white matter (PWM) vs. cortical and deep gray matter (CDGM) lesions and (2) to explore the relation between UL kinematics and lesion location and extent within each lesion timing group. Methods: Forty-eight children (age 10.4 ± 2.7 year; 29 boys; 21 right-sided; 33 PWM; 15 CDGM) underwent an UL 3DMA during a reach-to-grasp task. Spatiotemporal parameters [movement duration, (timing of) maximum velocity, trajectory straightness], the Arm Profile Score (APS) and Arm Variable Scores (AVS) were extracted. The APS and AVS refer to the total amount of movement pathology and movement deviations of the wrist, elbow, shoulder, scapula and trunk respectively. Brain lesion location and extent were scored based on FLAIR-images using a semi-quantitative MRI-scale. Results: Children with CDGM lesions showed more aberrant spatiotemporal parameters (p < 0.03) and more movement pathology (APS, p = 0.003) compared to the PWM group, mostly characterized by increased wrist flexion (p = 0.01). In the CDGM group, moderate to high correlations were found between lesion location and extent and duration, timing of maximum velocity and trajectory straightness (r = 0.53-0.90). Lesion location and extent were further moderately correlated with distal UL movement pathology (wrist flexion/extension, elbow pronation/supination, elbow flexion/extension; r = 0.50-0.65) and with the APS (r = 0.51-0.63). In the PWM group, only a few and low correlations were observed, mostly between damage to the PLIC and higher AVS of elbow flexion/extension, shoulder elevation and trunk rotation (r = 0.35-0.42). Regression analysis revealed damage to the temporal lobe with lesion timing as interactor (27%, p = 0.002) and the posterior limb of the internal capsule (PLIC) (7%, p = 0.04) as the strongest predictors, explaining 34% of the variance in APS. Conclusion: UL kinematic deviations are more influenced by lesion location and extent in children with later (CDGM) versus earlier lesions (PWM), except for proximal movement pathology. Damage to the PLIC is a significant predictor for UL movement pathology irrespective of lesion timing.

The neurophysiology of paediatric movement disorders

PURPOSE OF REVIEW

To demonstrate how neurophysiological tools have advanced our understanding of the pathophysiology of paediatric movement disorders, and of neuroplasticity in the developing brain.

RECENT FINDINGS

Delineation of corticospinal tract connectivity using transcranial magnetic stimulation (TMS) is being investigated as a potential biomarker for response to therapy. TMS measures of cortical excitability and neuroplasticity are also being used to investigate the effects of therapy, demonstrating neuroplastic changes that relate to functional improvements. Analyses of evoked potentials and event-related changes in the electroencephalogaphy spectral activity provide growing evidence for the important role of aberrant sensory processing in the pathophysiology of many different movement disorders. Neurophysiological findings demonstrate that children with clinically similar phenotypes may have differing underlying pathophysiology, which in turn may explain differential response to therapy. Neurophysiological parameters can act as biomarkers, providing a means to stratify individuals, and are well suited to provide biofeedback. They therefore have enormous potential to facilitate improvements to therapy.

SUMMARY

Although currently a small field, the role of neurophysiology in paediatric movement disorders is poised to expand, both fuelled by and contributing to the rapidly growing fields of neuro-rehabilitation and neuromodulation and the move towards a more individualized therapeutic approach.