Donna Nimec

Cortical Somatosensory Reorganization in Children with Spastic Cerebral Palsy: A Multimodal Neuroimaging Study

Although cerebral palsy (CP) is among the most common causes of physical disability in early childhood, we know little about the functional and structural changes of this disorder in the developing brain. Here, we investigated with three different neuroimaging modalities [magnetoencephalography (MEG), diffusion tensor imaging (DTI), and resting-state fMRI] whether spastic CP is associated with functional and anatomical abnormalities in the sensorimotor network. Ten children participated in the study: four with diplegic CP (DCP), three with hemiplegic CP (HCP), and three typically developing (TD) children. Somatosensory (SS)-evoked fields (SEFs) were recorded in response to pneumatic stimuli applied to digits D1, D3, and D5 of both hands. Several parameters of water diffusion were calculated from DTI between the thalamus and the pre-central and post-central gyri in both hemispheres. The sensorimotor resting-state networks (RSNs) were examined by using an independent component analysis method. Tactile stimulation of the fingers elicited the first prominent cortical response at ~50u2009ms, in all except one child, localized over the primary SS cortex (S1). In five CP children, abnormal somatotopic organization was observed in the affected (or more affected) hemisphere. Euclidean distances were markedly different between the two hemispheres in the HCP children, and between DCP and TD children for both hemispheres. DTI analysis revealed decreased fractional anisotropy and increased apparent diffusion coefficient for the thalamocortical pathways in the more affected compared to less affected hemisphere in CP children. Resting-state functional MRI results indicated absent and/or abnormal sensorimotor RSNs for children with HCP and DCP consistent with the severity and location of their lesions. Our findings suggest an abnormal SS processing mechanism in the sensorimotor network of children with CP possibly as a result of diminished thalamocortical projections.

Robotic Gait Training in an Adult With Cerebral Palsy: A Case Report

Improved treatments and rehabilitation for cerebral palsy (CP) have led to an increased number of children with CP surviving into adulthood. Adults with CP show an increased prevalence of pain, fatigue, and musculoskeletal dysfunction, leading to a decrease in ambulatory function. Recent work has demonstrated the potential benefits of intensive task‐specific gait training, including the use of robotic‐driven gait orthoses, on motor recovery in children with CP [ 1,2 ]. In contrast, reports of interventions aimed at improving motor function in adults with CP are lacking. This case study reports on the outcomes of a 6‐week intervention of robotic‐assisted gait training administered to a 52‐year‐old woman with right hemiplegia attributable to CP. Improvements were noted in balance, walking speed, and time to negotiate stairs at posttraining and follow‐up. Gait analysis showed an increase in step length and a reduction in the period of double support. In conclusion, robotic‐assisted gait training may be beneficial in enhancing locomotor function in adults with CP.

A novel sensorized shoe system to classify gait severity in children with cerebral palsy

The clinical management of children with Cerebral Palsy (CP) relies upon periodic assessments of changes in the severity of gait deviations in response to clinical interventions. Current clinical practice is limited to sporadic assessments in a clinical environment and hence it is limited in its ability to estimate the impact of CP-related gait deviations in real-life conditions. Frequent home-based quantitative assessments of the severity of gait deviations would be extremely useful in scheduling clinical visits and gathering feedback about the effectiveness of intervention strategies. The use of a wearable system would allow clinicians to gather information about the severity of gait deviations in the home setting. In this paper, we present ActiveGait, a novel sensorized shoe-based system for monitoring gait deviations. The ActiveGait system was used to gather data, under supervised and unsupervised conditions, from a group of 11 children with various levels of CP-related gait deviation severities. We present a methodology to derive severity measures based on features extracted from Center of Pressure (CoP) trajectories. Results show that a Random Forest classifier is able to estimate severity scores based on the Edinburgh Visual Scale with a level of accuracy >;80% adequate for clinical use.

Enhancing robotic gait training via augmented feedback

Recent work has examined the feasibility of robotic-assisted gait training in pediatric patients, including children with cerebral palsy (CP). Herein we present a case series describing clinical outcomes in four children with CP who underwent gait training using a robotic driven gait orthosis (DGO) (Pediatric Lokomat©). Children had a diagnosis of spastic diplegia due to CP. They were paired based on functional abilities and observed gait characteristics. Two children had a GMFCS of III and showed excessive ankle plantarflexion during stance. The other two children had a GMFCS of II and displayed a crouch gait pattern. Each subject participated in a 6-week intervention of robotic-assisted gait training that involved three 30-minute sessions per week. Pre-and post-training evaluations were performed including clinical tests of standing and walking function, walking speed, and walking endurance. Clinical gait analysis was also performed using a motion capture system to assess changes in gait mechanics. All subjects showed an improvement in locomotor function. For lower functioning children, this may be mediated by improved trunk control. The use of augmented feedback was associated with larger. However, these results have to be considered with caution because of the limited sample size of the study.

Reorganization of the somatosensory cortex in hemiplegic cerebral palsy associated with impaired sensory tracts

Functional neuroimaging studies argue that sensory deficits in hemiplegic cerebral palsy (HCP) are related to deviant somatosensory processing in the ipsilesional primary somatosensory cortex (S1). A separate body of structural neuroimaging literature argues that these deficits are due to structural damage of the ascending sensory tracts (AST). The relationship between the functional and structural integrity of the somatosensory system and the sensory performance is largely unknown in HCP. To address this relationship, we combined findings from magnetoencephalography (MEG) and probabilistic diffusion tractography (PDT) in 10 children with HCP and 13 typically developing (TD) children. With MEG, we mapped the functionally active regions in the contralateral S1 during tactile stimulation of the thumb, middle, and little fingers of both hands. Using these MEG-defined functional active regions as regions of interest for PDT, we estimated the diffusion parameters of the AST. Somatosensory function was assessed via two-point discrimination tests. Our MEG data showed: (i) an abnormal somatotopic organization in all children with HCP in either one or both of their hemispheres; (ii) longer Euclidean distances between the digit maps in the S1 of children with HCP compared to TD children; (iii) suppressed gamma responses at early latencies for both hemispheres of children with HCP; and (iv) a positive correlation between the Euclidean distances and the sensory tests for the more affected hemisphere of children with HCP. Our MEG-guided PDT data showed: (i) higher mean and radian diffusivity of the AST in children with HCP; (ii) a positive correlation between the axial diffusivity of the AST with the sensory tests for the more affected hemisphere; and (iii) a negative correlation between the gamma power change and the AD of the AST for the MA hemisphere. Our findings associate for the first time bilateral cortical functional reorganization in the S1 of HCP children with abnormalities in the structural integrity of the AST, and correlate these abnormalities with behaviorally-assessed sensory deficits.

Predictors of Postoperative Rehabilitation Therapy Following Congenital Heart Surgery

Background Patients with congenital heart disease are at risk of motor, cognitive, speech, and feeding difficulties after cardiac surgery. Rehabilitation therapy could improve functional outcomes in this population if applied in the acute postcardiac surgical in‐hospital stay. However, information on the types of acute postcardiac surgery therapy needs in children is scarce. Our goal was to describe rehabilitation therapy following congenital heart surgery and pre/intraoperative factors associated with need for therapy. Methods and Results This is a retrospective cohort study of patients <18 years undergoing heart surgery at our center from January 1, 2013 to January 31, 2015. Demographic, and pre‐, intra‐, and postoperative clinical and rehabilitation therapy (physical, occupational, speech, feeding therapy, and neurodevelopment intervention) data were collected. Need for rehabilitation therapy in the acute postoperative period, particularly following palliative repair, was the outcome variable in a multivariable logistic regression model to identify independent pre‐ and intraoperative factors associated with therapy. A total of 586 out of 1415 (41%) subjects received rehabilitation therapy postsurgery. Certain subgroups had increased rehabilitation therapy use such as neonates (80%). On multivariable analysis, palliative repair, prematurity, genetic syndrome, presurgical hospital stay of more than 1 day, and prolonged cardiopulmonary bypass time were independently associated with rehabilitation therapy. Conclusions Nearly half of patients who underwent post–congenital heart surgery received rehabilitation therapy. Frequency of use and types of therapy vary according to patient characteristics; however, certain pre‐ and intraoperative factors are associated with need for rehabilitation therapy, and may aid decision‐making for appropriate resource allocation.