Stakeholder Perspectives on Engaging With Cerebral Palsy Research Studies After Onset of COVID-19 in the United States.

OBJECTIVE: To investigate the effect of the coronavirus disease 2019 (COVID-19) pandemic on perspectives toward participation in cerebral palsy (CP) research. DESIGN: An online survey with questions relating to the comfort levels of research participation was filled out by people who had CP or had a child with CP. SETTING: The online survey was administered through Research Electronic Data Capture platform. PARTICIPANTS: A total of 233 (n=233) individuals with CP (42.5%; n=99) or with a child with CP (57.1%; n=133) consented and at least partially completed the online survey (n=210 complete; n=23 partially complete). All participants resided in the United States. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Readiness to participate was analyzed in the context of the time point for research participation during COVID-19 and whether or not the study offered direct benefits to participants. RESULTS: Participants were consistently willing to participate sooner in studies that offered direct benefit than in those that did not. Adults responding for themselves had sooner time points for studies without direct benefit compared with parents answering for a child (P=.030). Gross Motor Function Classification System level, but not age or CP type, affected the time point for studies without direct benefit (P=.017). Personal values influenced selected time point for studies without direct benefit (P=.007), whereas environmental factors affected the time point for studies with direct benefit (P=.002). Local COVID-19 incidence rates were not associated with time points for either research type; however, respondents expected precautions to be taken if they chose to participate. CONCLUSIONS: As the pandemic evolves, researchers should consider the perspectives of potential participants as well as ethical and safety factors when reinitiating in-person CP research.

Age-dependent predictors of effective reinforcement motor learning across childhood.

Across development, children must learn motor skills such as eating with a spoon and drawing with a crayon. Reinforcement learning, driven by success and failure, is fundamental to such sensorimotor learning. It typically requires a child to explore movement options along a continuum (grip location on a crayon) and learn from probabilistic rewards (whether the crayon draws or breaks). Here, we studied the development of reinforcement motor learning using online motor tasks to engage children aged 3 to 17 and adults (cross-sectional sample, N=385). Participants moved a cartoon penguin across a scene and were rewarded (animated cartoon clip) based on their final movement position. Learning followed a clear developmental trajectory when participants could choose to move anywhere along a continuum and the reward probability depended on final movement position. Learning was incomplete or absent in 3 to 8-year-olds and gradually improved to adult-like levels by adolescence. A reinforcement learning model fit to each participant identified three age-dependent factors underlying improvement: amount of exploration after a failed movement, learning rate, and level of motor noise. We predicted, and confirmed, that switching to discrete targets and deterministic reward would improve 3 to 8-year-olds' learning to adult-like levels by increasing exploration after failed movements. Overall, we show a robust developmental trajectory of reinforcement motor learning abilities under ecologically relevant conditions i.e., continuous movement options mapped to probabilistic reward. This learning appears to be limited by immature spatial processing and probabilistic reasoning abilities in young children and can be rescued by reducing the demands in these domains.

The Scale for Assessment and Rating of Ataxia Is Reliable and Valid in the Telehealth Setting for Patients With Cerebellar Ataxia.

OBJECTIVE: Health care has increasingly expanded into a hybrid in-person/telehealth model. Patients with a variety of health conditions, including cerebellar ataxia, have received virtual health evaluations; however, it remains unknown whether some outcome measures that clinicians utilize in the telehealth setting are reliable and valid. The goal of this project is to evaluate the psychometric properties of the Scale for Assessment and Rating of Ataxia (SARA) for patients with cerebellar ataxia in the telehealth setting. METHODS: Nineteen individuals with cerebellar impairments were recruited on a voluntary basis. Participants completed 2 30-minute testing sessions during which a clinical examination and the SARA were performed. One session was performed in person, and the other session was assessed remotely. Outcome measure performance was video recorded in both environments and independently scored by 4 additional raters with varying levels of clinical experience (ranging from 6 months to 29 years). Concurrent validity was assessed with the Spearman rank order correlation coefficient (α < .05), comparing the virtual SARA scores to their gold standard in-person scores. Interrater reliability was evaluated with the intraclass correlation coefficient (ICC) (2,4) (α < .05). RESULTS: Fourteen of the 19 participants completed both in-person and telehealth SARA evaluations. We found that the in-person SARA and the telehealth SARA have large concurrent validity (Spearman rho significant at the 2-tailed α of .01 = 0.90; n = 14). Additionally, raters of varying years of experience had excellent interrater reliability for both the in-person SARA (ICC [2,4] = 0.97; n = 19) and the telehealth SARA (ICC [2,4] = 0.98; n = 14). CONCLUSION: Our results show that the telehealth SARA is comparable to the in-person SARA. Additionally, raters of varying years of clinical experience were found to have excellent interrater reliability scores for both remote and in-person SARA evaluations. IMPACT: Our study shows that the SARA can be used in the telehealth setting for patients with ataxia.

Stroke in the Developing Brain: Neurophysiologic Implications of Stroke Timing, Location, and Comorbid Factors.

BACKGROUND: Pediatric stroke, which is unique in that it represents a static insult to a developing brain, often leads to long-term neurological disability. Neuroplasticity in infants and children influences neurophysiologic recovery patterns after stroke; therefore outcomes depend on several factors including the timing and location of stroke and the presence of comorbid conditions. METHODS: In this review, we discuss the unique implications of stroke occurring in the fetal, perinatal, and childhood/adolescent time periods. First, we highlight the impact of the developmental stage of the brain at the time of insult on the motor, sensory, cognitive, speech, and behavioral domains. Next, we consider the influence of location of stroke on the presence and severity of motor and nonmotor outcomes. Finally, we discuss the impact of associated conditions on long-term outcomes and risk for stroke recurrence. RESULTS: Hemiparesis is common after stroke at any age, although the severity of impairment differs by age group. Risk of epilepsy is elevated in all age groups compared with those without stroke. Outcomes in other domains vary by age, although several studies suggest worse cognitive outcomes when stroke occurs in early childhood compared with fetal and later childhood epochs. Conditions such as congenital heart disease, sickle cell disease, and moyamoya increase the risk of stroke and leave patients differentially vulnerable to neurodevelopmental delay, stroke recurrence, silent infarcts, and cognitive impairment. CONCLUSIONS: A comprehensive understanding of the interplay of various factors is essential in guiding the clinical care of patients with pediatric stroke.

A novel video game for remote studies of motor adaptation in children.

Here we designed a motor adaptation video game that could be played remotely (at home) through a web browser. This required the child to adapt to a visuomotor rotation between their hand movement and a ball displayed in the game. The task had several novel features, specifically designed to allow the study of the developmental trajectory of adaptation across a wide range of ages. We test the concurrent validity by comparing children's performance on our remote task to the same task performed in the laboratory. All participants remained engaged and completed the task. We quantified feedforward and feedback control during this task. Feedforward control, a key measure of adaptation, was similar at home and in the laboratory. All children could successfully use feedback control to guide the ball to a target. Traditionally, motor learning studies are performed in a laboratory to obtain high quality kinematic data. However, here we demonstrate concurrent validity of kinematic behavior when conducted at home. Our online platform provides the flexibility and ease of collecting data that will enable future studies with large sample sizes, longitudinal experiments, and the study of children with rare diseases.

Customized gaming system engages young children in reaching and balance training.

Purpose: Trunk stability, an important prerequisite for many activities of daily living, can be impaired in children with movement disorders. Current treatment options can be costly and fail to fully engage young participants. We developed an affordable, smart screen-based intervention and tested if it engages young children in physical therapy goal driven exercises. Methods: Here we describe the ADAPT system, Aiding Distanced and Accessible Physical Therapy, which is a large touch-interactive device with customizable games. One such game, "Bubble Popper," encourages high repetitions of weight shifts, reaching, and balance training as the participant pops bubbles in sitting, kneeling, or standing positions. Results: Sixteen participants aged 2-18 years were tested during physical therapy sessions. The number of screen touches and length of game play indicate high participant engagement. In trials lasting less than 3 min, on average, older participants (12-18 years) made 159 screen touches per trial while the younger participants (2-7 years) made 97. In a 30-min session, on average, older participants actively played the game for 12.49 min while younger participants played for 11.22 min. Conclusion: The ADAPT system is a feasible means to engage young participants in reaching and balance training during physical therapy.

Between Limb Muscle Co-activation Patterns in the Paretic Arm During Non-paretic Arm Tasks in Hemiparetic Cerebral Palsy.

Tasks of daily life require the independent use of the arms and hands. Individuals with hemiparetic cerebral palsy (HCP) often experience difficulty with fine motor tasks demonstrating mirrored movements between the arms. In this study, bilateral muscle activations were quantified during single arm isometric maximum efforts and submaximal reaching tasks. The magnitude and direction of mirrored activation was examined in 14 individuals with HCP and 9 age-matched controls. Participants generated maximum voluntary torques (MVTs) in five different directions and completed ballistic reaches while producing up to 80% of shoulder abduction MVT. Electromyography (EMG) signals were recorded from six upper extremity muscles bilaterally. Participants with HCP demonstrated more mirrored activation when volitionally contracting the non-paretic (NP) arm than the paretic arm (F = 83.543, p < 0.001) in isometric efforts. Increased EMG activation during reach acceleration resulted in a larger increase in rest arm co-activation when reaching with the NP arm compared to the paretic arm in the HCP group (t = 8.425, p < 0.001). Mirrored activation is more pronounced when driving the NP arm and scales with effort level. This directionality of mirroring is indicative of the use of ipsilaterally terminating projections of the corticospinal tract (CST) originating in the non-lesioned hemisphere. Peripheral measures of muscle activation provide insight into the descending pathways available for control of the upper extremity after early unilateral brain injury.

The Upper Extremity Flexion Synergy Is Minimally Expressed in Young Individuals With Unilateral Cerebral Palsy Following an Early Brain Injury.

Hemiparetic stroke in adulthood often results in the grouped movement pattern of the upper extremity flexion synergy thought to arise from an increased reliance on cortico-reticulospinal pathways due to a loss of lateral corticospinal projections. It is well established that the flexion synergy induces reaching constraints in individuals with adult-onset hemiplegia. The expression of the flexion synergy in individuals with brain injuries onset earlier in the lifespan is currently unknown. An early unilateral brain injury occurring prior to six months post full-term may preserve corticospinal projections which can be used for independent joint control and thus minimizing the expression of the flexion synergy. This study uses kinematics of a ballistic reaching task to evaluate the expression of the flexion synergy in individuals with pediatric hemiplegia (PH) ages six to seventeen years. Fifteen individuals with brain injuries before birth (n = 8) and around full-term (n = 7) and nine age-matched controls with no known neurological impairment completed a set of reaches in an admittance controlled robotic device. Descending drive, and the possible expression of the upper extremity flexion synergy, was modulated by increasing shoulder abduction loading. Individuals with early-onset PH achieved lower peak velocities when reaching with the paretic arm compared to controls; however, no differences in reaching distance were found between groups. Relative maintenance in reaching seen in individuals with early brain injuries highlights minimal expression of the flexion synergy. We interpret this conservation of independent control of the paretic shoulder and elbow as the use of more direct corticospinal projections instead of indirect cortico-reticulospinal pathways used in individuals with adult-onset hemiplegia.

Development of a Method to Quantify Abnormal Kinetic and Kinematic Coupling Patterns during Functional Movements in the Paretic Arm and Hand of Individuals with Pediatric Hemiplegia.

A main focus of clinical interventions for adults after a stroke and children with hemiplegia is upper limb motor impairments. Robotic and motion capture technologies have been used to quantify the presence of abnormal joint coupling patterns in the arm and hand in adults who have had a stroke. Similar impairments have been observed clinically in children with hemiplegia, however, quantitative measurement tools tailored for this population are lacking. Here, we describe the integration of haptic robotics, pressure recording, and motion capture designed specifically for use with pediatric participants. Preliminary results demonstrate that these measurement techniques are effective in quantifying deficits in reaching abilities in this population.

Estimating Voluntary Activation Of The Elbow And Wrist Muscles In Chronic Hemiparetic Stroke Using Twitch Interpolation Methodology.

One of the cardinal motor deficits that occurs after stroke is paresis, a decrease in the voluntary activation of muscles. Paresis leads to a decrease in voluntary joint strength, impacting stroke survivors' ability to perform activities of daily living (ADLs). Quantifying this decrease in voluntary activation is important when designing rehabilitation interventions to address movement impairments and restore the ability to perform ADLs. Twitch interpolation is an experimental technique developed to quantify muscle voluntary activation [1]. This method has been used widely across pathologies but often limited to assessment of the voluntary activation of the plantar flexors, given the ease of activating these muscles through stimulation of the tibial nerve [2]. The complex innervation of elbow and wrist musculature imposes practical difficulties when applying the twitch interpolation technique to these joints [1]. Therefore, only a few studies have used this technique to examine the pathological [3]-[5] upper extremity, with little quantitative data documenting the degree of paresis present in the upper limb after stroke. The goal of this study is to evaluate the feasibility of applying twitch interpolation to quantify voluntary activation of the elbow and wrist flexors and extensors in chronic stroke survivors.