Deficits in executed and imagined aiming performance in brain-injured children

Integrating Transcranial Direct Current Stimulation into an Existing Inpatient Physiotherapy Program to Enhance Motor Learning in an Adolescent with Traumatic Brain Injury: A Case Report

PURPOSE

Describe how transcranial direct current stimulation (tDCS) was incorporated into an inpatient physiotherapy program for an adolescent with severe traumatic brain injury (TBI), detail the motor learning focus of the physiotherapy sessions, and summarize gross motor progress.

METHOD

This case report describes an adolescent who received 20 minutes of anodal tDCS immediately prior to 16 physiotherapy sessions over four weeks. Potential side effects were tracked pre/post tDCS. Gross motor outcomes were measured pre-intervention, post-intervention, and three months post-intervention. Physiotherapy session content was analyzed using therapist documentation and the Motor Learning Strategies Rating Instrument.

RESULTS

The youth tolerated tDCS well. The primary side effect was itchiness under the electrodes during tDCS sessions. His mobility progressed from wheelchair use pre- 'tDCS + physiotherapy' to ambulation with a walker post-intervention. His Gross Motor Function Measure score increased 33.1% points pre/post intervention. Session tasks often had several foci (e.g., skill acquisition, strength, and balance) with task focus changing as the youth progressed. Various motor learning strategies were layered within tasks to support performance and learning.

CONCLUSIONS

tDCS was successfully integrated into an existing inpatient physiotherapy program for an adolescent with TBI. This protocol provides a structure for implementing, monitoring, and measuring tDCS + physiotherapy in pediatric rehabilitation.

Body Processing in Children and Adolescents with Traumatic Brain Injury: An Exploratory Study

Dysfunctions in body processing have been documented in adults with brain damage, while limited information is available for children. This study aimed to investigate body processing in children and adolescents with traumatic brain injury (TBI) (N = 33), compared to peers with typical development. Two well-known computerized body-representation paradigms, namely Visual Body Recognition and Visuo-spatial Imagery, were administered. Through the first paradigm, the body inversion and composite illusion effects were tested with a matching to sample task as measures of configural and holistic processing of others’ bodies, respectively. The second paradigm investigated with a laterality judgement task the ability to perform first-person and object-based mental spatial transformations of own body and external objects, respectively. Body stimuli did not convey any emotional contents or symbolic meanings. Patients with TBI had difficulties with mental transformations of both body and object stimuli, displaying deficits in motor and visual imagery abilities, not limited to body processing. Therefore, cognitive rehabilitation of body processing in TBI might benefit from the inclusion of both general training on visuo-spatial abilities and specific exercises aimed at boosting visual body perception and motor imagery.

Use of Motor Learning Strategies in Occupational Therapy for Children and Youth with Acquired Brain Injury

Motor learning strategies (MLS) can be used to promote motor skills acquisition in children and youth with acquired brain injury (ABI). While occupational therapists (OTs) likely use MLS in clinical practice, research has not investigated the extent and variety of their application.Aims: This study explored MLS use by OTs in pediatric ABI and factors influencing their application.Method: Individual video-recorded occupational therapy sessions for a sample of eight children/youth (ages 4-16) with ABI were evaluated via mixed methods approach. The Motor Learning Strategies Rating Instrument (MLSRI-22) quantified the extent of MLS use in each video. Directed content analysis of the videos explored the factors influencing how and when MLS were applied.Results: The most frequently used MLS were promoting problem solving, encouragement, directing attention to the body, permitting errors as part of learning, repetitive practice, and whole practice. Three themes described how and when the OTs used MLS: 1) Getting buy-in, 2) Going with the flow, and 3) Movement and thinking go hand-in-hand.Conclusions: The OTs frequently used MLS with children with ABI, appearing to select MLS based on factors related to the child, task, and environment. These findings are fundamental to future exploration of OT decision-making and evaluation of MLS effectiveness.

The development of anticipatory action planning in children with unilateral cerebral palsy

Background Previous studies suggest that compromised bimanual performance experienced by children with unilateral cerebral palsy (CP) is not only due to difficulties in action execution but may also be a result of impaired anticipatory action planning. Aims The effect of age and side of hemiplegia were examined and the relationship between anticipatory action planning, unimanual capacity and bimanual performance was explored. Methods and procedures Using a multi-centre, prospective, cross-sectional observational design, anticipatory action planning was analyzed in 104 children with unilateral cerebral palsy, aged 6-12 years, using the sword task. Outcomes and results Anticipatory action planning did not improve with age in children with unilateral CP, aged between 6-12 years. No differences were found between children with left or right hemiplegia. Finally, anticipatory action planning was not related to unimanual capacity or bimanual performance. Conclusion and implications This study demonstrates anticipatory action planning, measured using the sword task, does not improve with age in children with unilateral CP and is not related to bimanual performance or laterality. Future studies of anticipatory action planning in children with unilateral CP should consider using measures that require effective anticipatory action planning for successful task completion rather than end state comfort.

Current insights in the development of children's motor imagery ability

Over the last two decades, the number of studies on motor imagery in children has witnessed a large expansion. Most studies used the hand laterality judgment paradigm or the mental chronometry paradigm to examine motor imagery ability. The main objective of the current review is to collate these studies to provide a more comprehensive insight in children’s motor imagery development and its age of onset. Motor imagery is a form of motor cognition and aligns with forward (or predictive) models of motor control. Studying age-related differences in motor imagery ability in children therefore provides insight in underlying processes of motor development during childhood. Another motivation for studying age-related differences in motor imagery is that in order to effectively apply motor imagery training in children (with motor impairments), it is pertinent to first establish the age at which children are actually able to perform motor imagery. Overall, performance in the imagery tasks develops between 5 and 12 years of age. The age of motor imagery onset, however, remains equivocal, as some studies indicate that children of 5 to 7 years old can already enlist motor imagery in an implicit motor imagery task, whereas other studies using explicit instructions revealed that children do not use motor imagery before the age of 10. From the findings of the current study, we can conclude that motor imagery training is potentially a feasible method for pediatric rehabilitation in children from 5 years on. We suggest that younger children are most likely to benefit from motor imagery training that is presented in an implicit way. Action observation training might be a beneficial adjunct to implicit motor imagery training. From 10 years of age, more explicit forms of motor imagery training can be effectively used.

Use of video observation and motor imagery on jumping performance in national rhythmic gymnastics athletes

The aim of this study was to evaluate whether a mental training protocol could improve gymnastic jumping performance. Seventy-two rhythmic gymnasts were randomly divided into an experimental and control group. At baseline, experimental group completed the Movement Imagery Questionnaire Revised (MIQ-R) to assess the gymnast ability to generate movement imagery. A repeated measures design was used to compare two different types of training aimed at improving jumping performance: (a) video observation and PETTLEP mental training associated with physical practice, for the experimental group, and (b) physical practice alone for the control group. Before and after six weeks of training, their jumping performance was measured using the Hopping Test (HT), Drop Jump (DJ), and Counter Movement Jump (CMJ). Results revealed differences between jumping parameters F(1,71)=11.957; p<.01, and between groups F(1,71)=10.620; p<.01. In the experimental group there were significant correlations between imagery ability and the post-training Flight Time of the HT, r(34)=-.295, p<.05 and the DJ, r(34)=-.297, p<.05. The application of the protocol described herein was shown to improve jumping performance, thereby preserving the elite athlete's energy for other tasks.

Differences in motor imagery time when predicting task duration in alpine skiers and equestrian riders

Athletes' ability to use motor imagery (MI) to predict the speed at which they could perform a motor sequence has received little attention. In this study, 21 alpine skiers and 16 equestrian riders performed MI based on a prediction of actual performance time (a) after the course inspection, (b) before the start, and (c) after the actual performance. MI and physical times were similar in expert skiers during each imagery session, while novice skiers and novice and expert riders underestimated the actual course duration. These findings provide evidence that the temporal accuracy of an imagery task prediction depends on the performer's expertise level and characteristics of the motor skill.

Passive motion paradigm: an alternative to optimal control

IN THE LAST YEARS, OPTIMAL CONTROL THEORY (OCT) HAS EMERGED AS THE LEADING APPROACH FOR INVESTIGATING NEURAL CONTROL OF MOVEMENT AND MOTOR COGNITION FOR TWO COMPLEMENTARY RESEARCH LINES: behavioral neuroscience and humanoid robotics. In both cases, there are general problems that need to be addressed, such as the "degrees of freedom (DoFs) problem," the common core of production, observation, reasoning, and learning of "actions." OCT, directly derived from engineering design techniques of control systems quantifies task goals as "cost functions" and uses the sophisticated formal tools of optimal control to obtain desired behavior (and predictions). We propose an alternative "softer" approach passive motion paradigm (PMP) that we believe is closer to the biomechanics and cybernetics of action. The basic idea is that actions (overt as well as covert) are the consequences of an internal simulation process that "animates" the body schema with the attractor dynamics of force fields induced by the goal and task-specific constraints. This internal simulation offers the brain a way to dynamically link motor redundancy with task-oriented constraints "at runtime," hence solving the "DoFs problem" without explicit kinematic inversion and cost function computation. We argue that the function of such computational machinery is not only restricted to shaping motor output during action execution but also to provide the self with information on the feasibility, consequence, understanding and meaning of "potential actions." In this sense, taking into account recent developments in neuroscience (motor imagery, simulation theory of covert actions, mirror neuron system) and in embodied robotics, PMP offers a novel framework for understanding motor cognition that goes beyond the engineering control paradigm provided by OCT. Therefore, the paper is at the same time a review of the PMP rationale, as a computational theory, and a perspective presentation of how to develop it for designing better cognitive architectures.

Co-regulation of movement speed and accuracy by children with heavy prenatal alcohol exposure

The study investigated how children with heavy prenatal alcohol exposure regulate movement speed and accuracy during goal-directed movements. 16 children ages 7 to 17 years with confirmed histories of heavy in utero alcohol exposure, and 21 nonalcohol-exposed control children completed a series of reciprocal tapping movements between two spatial targets. 5 different targets sets were presented, representing a range of task difficulty between 2 and 6 bits of information. Estimates of percent error rate, movement time, slope, and linear fit of the resulting curve confirmed that for goal-directed, reciprocal tapping responses, performance of the group with prenatal alcohol exposure was described by a linear function, as predicted by Fitts' law, by sacrificing movement accuracy. The index of performance was the same for the two groups: it initially increased, then leveled off for more difficult movements.