Therapeutic Effects of an Anti-Gravity Treadmill (AlterG) Training on Neuromuscular Abnormalities Associated with Spasticity in Children with Cerebral Palsy.

We aimed to characterize the therapeutic effects of Anti-Gravity Treadmill (AlterG) Training on neuromuscular abnormalities associated with spasticity in children with cerebral palsy (CP). Eighteen subjects were divided into two groups; AlterG and control. All subjects received up to 40 minutes of training 3 times a week for 8 weeks. The control group received conventional occupational therapy. The advanced parallel-cascade system identification technique was used to characterize the neuromuscular abnormalities associated with spasticity and separated its intrinsic and reflex components. Reflex stiffness gain (GR) and intrinsic stiffness gain (K) were used to track the therapeutic effects of training on neural and muscular abnormalities. Both K and GR were strongly positioned dependent; they varied linearly with the ankle angle at dorsiflexion. Their position dependence was quantified by fitting a linear model to K and GR over dorsiflexion positions. The evaluations were performed at four-time points; i.e. the baseline (before starting the training), 1 and 2 months after starting the training, and 1 month after the completion of the training to assess the persistent effects. We determined the changes in K and GR intercept and slope parameters over these 3 months to evaluate the therapeutic effects of training on neuromuscular abnormalities. The results revealed that all K and GR parameters decreased substantially following using AlterG training and these changes were greater than those observed in the control. The results also showed that these therapeutic effects were persistent to a high extent, particularly in the AlterG group. Our findings suggested that AlterG training could be considered as a robust therapeutic intervention to reduce neuromuscular abnormalities and manage spasticity.

The Therapeutic Effects of Low-Amplitude, High-Frequency Perturbations on Neuromuscular Abnormalities Associated with Spasticity in Children with Cerebral Palsy.

We aimed to investigate the impact of ankle joint therapy with low-amplitude, high-frequency perturbation training on neuromuscular abnormalities associated with spasticity in children with Cerebral Palsy (CP). Four spastic CP children (2 males and 2 females) received a 10-session training of high-frequency and low-amplitude perturbations superimposed on passive stretches over the range of motion of their ankle as well as local perturbations at dorsiflexion position. The associated passive parameters, including total passive range of motions, passive range of motions toward dorsiflexion, stiffness, energy loss and torque dynamic gain were evaluated at the baseline and after a 10 session training. Our findings indicate that passive range of motion increased, and passive reflex stiffness, which usually increases in CP children, decreased following the completion of training. Our results demonstrate that intensive sessions of perturbation therapy could be considered an effective therapeutic mean for the management of spasticity and contracture, and eventually the enhancement of mobility of CP children.

Impact of anti-gravity locomotion (AlterG) training on structure and function of corticospinal tract and gait in children with cerebral palsy.

We aimed to characterize the impact of anti-gravity locomotion training on the structure and function of the corticospinal tract (CST) in cerebral palsy (CP). Fourteen CP children participated. Nine children were trained with an antigravity treadmill (Alter-G) and five children received occupational therapy (OT). Treatments were provided for 45 min each session, 3 sessions per week for 8 weeks. Diffusion tensor imaging (DTI) was used, and fractional anisotropy (FA), mean diffusivity (MD), radial (RD) and axial (AD) diffusivity was extracted to characterize the structure of the CST. Transcranial magnetic stimulation (TMS) was used and threshold, latency, and peak-peak amplitude of the MEP signal, elicited by the TMS, were used to quantify the function of the CST. Walking ability was evaluated by measuring gait speed, endurance, balance, and mobility. The evaluations were performed before and after the interventions. The results showed that FA improved in both sides of the brain for the AlterG group, but enhanced only in the less affected side of the OT group. MD, RD, and AD mostly improved in the more affected side of the AlterG group. The enhancement of the CST function was similar in both groups. Walking speed and endurance also enhanced in both groups, but the improvement was greater in the AlterG group. Our findings demonstrate that AlterG training can improve gait ability, and simultaneously result in brain neuroplasticity. The clinical implication is that AlterG training can be used as an effective rehabilitation approach to improve gait persistently.

Does repetitive Transcranial Magnetic Stimulation (rTMS) have therapeutic effects on Dynamic Balance of Children with Cerebral Palsy?

Our big goal in this research was to evaluate the therapeutic effects of repetitive Transcranial Magnetic Stimulation (rTMS) on cerebral palsy (CP) children with balance deficits. Four spastic hemiplegic CP children were participated; the experimental group received rTMS training 4 days a week for 3 weeks and then for the next 3 weeks they received typical occupational therapy just after rTMS therapy. The control group received placebo rTMS instead of real one accordingly. Their dynamic balance was evaluated before the start of the treatment and 6 weeks after it. Center of pressure (COP) and center of mass (COM) features were regarded as dynamic balance parameters. Our results showed that the peak to peak of COP, COM, COM-COP, COM-COP inclination angles all improved for both experimental (15-86%) and control group patients, though there was less improvement about 8-46% in features of the control patients. Our results demonstrate that intensive sessions of the rTMS training could have the potential to enhance the therapeutic effects of typical occupational therapy that can produce dynamic balance improvements in CP children compared to using the occupational therapy by itself.

Resting-State Functional Connectivity in Popular Targets for Deep Brain Stimulation in the Treatment of Major Depression: An Application of a Graph Theory.

We examined the functional connectivity of subcallosal cingulate gyrus (SCG), nucleus accumbens (NAc), and ventral caudate (VCa), the main target areas for the treatment of major depression disorder (MDD), using deep brain stimulation (DBS). MDD is one of the most common diseases in the world, and approximately 30% of MDD patients do not respond to common therapies, including psychotherapy and antidepressant medications. Alternatively, DBS has been recently used to treat MDD. Resting state fMRI was obtained from seventeen healthy subjects and seven MDD patients. The functional connectivity network of the brain was constructed for all subjects and measured by the `degree' value for each SCG, NAc, and VCa regions using the graph theory analysis. The results show that the degree values of VCa and the left SCG are higher in the MDD group than the healthy group. Furthermore, the patterns of the degree values were different for the right and left hemispheres in MDD patients. Our findings suggest that degree values and their patterns have a potential to be used as diagnosis tools to detect the brain areas with abnormal functional connectivity.

The Effects of Repetitive Transcranial Magnetic Stimulation (rTMS) on Balance Control in Children with Cerebral Palsy.

Cerebral palsy (CP) is a neurological disorder which can result in balance and mobility impairments. Four children with spastic CP participated and randomly assigned to experimental and control groups. The experimental group received 1-Hz repetitive Transcranial Magnetic Stimulation (rTMS) four times a week for 3 weeks, and the control group received sham rTMS using the similar experimental protocol. Each rTMS session lasted for 20 minutes. Postural balance was quantified by analyzing the center of pressure (COP) signal of a force plate according to the Romberg test. The balance was also evaluated using the Berg Balance Scale (BBS). The evaluations were done before and after the treatment. COP signal features showed up to 70% improvement following rTMS treatment, whereas there was no notable improvements in the control group. Similarly the BBS assessment presented balance enhancement only in the experimental group. These results, particularly under closed eye foam condition may imply an improvement in proprioception system.Our findings suggested that rTMS has a potential to be used as a therapeutic method to improve postural balance in children with CP.

The Effects of Anti-gravity Treadmill Training on Gait Characteristics in Children with Cerebral Palsy.

Cerebral palsy is a disorder that affects muscle tone, movement and motor skills. Most of the children with cerebral palsy (CP) are not able to walk or can walk in incorrect pattern and are dependent on assistive devices. Recently an antigravity treadmill has been found to be beneficial as a new therapeutic approach. Thus, we aimed to investigate the effects of antigravity treadmill training (AlterG) on gait characteristic in children with cerebral palsy. We provided a 45-minute training program, 3 times a week for 8 weeks for six CP children as our experimental group. Our control group was a group consisted of four CP children who took typical occupational therapy, accordingly. All subjects in both AlterG and control groups were evaluated at the gait lab before and after 8 weeks training. Gait patterns were characterized using spatiotemporal parameters and dynamic balance features. We also evaluated the popular clinical gait measures including walking speed and endurance, and mobility and balance.Our results demonstrated that spatiotemporal, dynamic balance and clinical features all improved more after 8 weeks AlterG training rather than control group ones. These findings suggest that AlterG training can be considered as an effective approach for improving walking ability and gait characteristics in children with cerebral palsy.

The Effects of Low Frequency Repetitive Transcranial Magnetic Stimulation on White Matter Structural Connectivity in Children with Cerebral Palsy.

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive treatment technique for recovery of movement disorders by altering cortical plasticity. In this research, we studied the effects of low-frequency rTMS on white matter (WM) structural connectivity and clinical parameters in children with cerebral palsy (CP).,Four spastic hemiplegic CP children were randomly divided into experimental and control groups. In the experimental group, at first, 1Hz rTMS treatment was performed 4 days/week for 3 weeks on two hemiplegia patients over a contralesional primary motor cortex (M1). Then, 1Hz rTMS treatment was performed 4 days/week for 3 weeks followed by a 30min occupational therapy (OT). In the control group, two CP children received sham rTMS for 3 weeks and then sham rTMS combined with OT for 3 weeks in the same schedule as the experimental group. Evaluations performed using diffusion tensor imaging (DTI), and clinical measurements of gait performance before and after the treatment. Graph theoretical analysis was used to characterize topological changes of structural connectivity. Our findings demonstrate the 1Hz rTMS is effective in improving motor activity in spastic hemiplegic CP children, and is more effective when combined with OT.

The Effects of Lower Body Positive Pressure Treadmill Training on Dynamic Balance of Children with Cerebral Palsy.

We aimed to characterize the therapeutic effects of Anti-gravity (AlterG) body weight supported treadmill training on the impaired balance of children with cerebral palsy (CP). Four spastic CP children participated; two received AlterG training 3 times a week for 8 weeks and the other two received typical occupational therapy accordingly. Their dynamic balance was evaluated before the start of the treatment and 2 months after it. Features related to the center of pressure (COP) and the center of mass (COM) were considered as dynamic balance parameters. Our results showed that the maximum velocity and acceleration of the COP and COM, the average variability (RMS) and peak to peak of the COM-COP separation, and RMS of velocity and acceleration of the COM and COP were all improved for both AlterG training patients (15-90%), though there was a limited improvement of 0.2-24% in some features of the control patients. Our results demonstrate that intensive sessions of the AlterG training program could have the potential to be used as a therapeutic tool that can produce dynamic balance improvements in CP children compared to that of typical occupational therapy.

Assessment of neuroplasticity of corticospinal tract induced by antigravity treadmill (AlterG) in cerebral palsy children.

The aim of this study was to assess neuroplasticity that occurred in the corticospinal tract (CST) following antigravity treadmill (AlterG) training. AlterG can facilitate walking by having up to an 80% reduction of weight-bearing in patients. Systematic and intensive gait training for sufficient periods of time may lead to neuroplasticity and walking capacity improvement. AlterG gait training was done for eight weeks, 3 sessions per week, and 45 minutes each session. Three cerebral palsy (CP) children participated in this study. The function and structure of CST on the brain's more affected side were evaluated using Transcranial Magnetic Stimulation (TMS) and Diffusion Tensor Imaging (DTI). Also, some common clinical tests were performed to evaluate walking capacity and endurance. DTI features such as fractional anisotropy (FA) and mean diffusivity (MD) as well as some TMS features were extracted to estimate structural changes of the CST. The evaluations were performed before and after 8week AlterG training. The results showed an improvement in the DTI metrics of the CST following AlterG training. Also, TMS parameters were improved and these changes in CST function and structure were concurrent with changes in walking capacity. These results suggest that AlterG training can be used as a therapeutic tool to provide an effective and persistent gait improvement in CP children.

The impact of AlterG training on balance and structure of vestibulospinal tract in cerebral palsy children.

We aimed to investigate the effects of an antigravity treadmill (AlterG) on the balance and structure of the vestibulospinal tract. The AlterG can reduce the weightbearing of patients and hence can facilitate their locomotion. Three children with cerebral palsy (CP) received AlterG training three days per week for eight weeks with each session lasting 45 minutes. The balance of children was evaluated using the Berg balance test and the Timed Up and Go (TUG) test. The diffusion tensor imaging (DTI) method was employed to quantify changes of the structure of the vestibulospinal tract. Evaluations were performed before and after the 8-week training. DTI metrics including fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD) and axial diffusivity (AD) were measured to evaluate the vestibulospinal tract structure. The results showed that the mean FA of the vestibulospinal tract increased and other metrics decreased for all subjects. Our findings indicated that the balance and structure of the vestibulospinal tract were improved up to 30% for all children following the 8-week AlterG training. This indicates that the balance improvement of the CP children following the AlterG training was accompanied with persistent neuroplasticity in their brain. The clinical implication is that the AlterG training has a potential to be used as an effective therapeutic tool for the treatment of balance impairment in CP children.

The impact of an anti-gravity treadmill (AlterG) training on walking capacity and corticospinal tract structure in children with cerebral palsy.

We studied the effects of an anti-gravity treadmill (AlterG) training on walking capacity and corticospinal tract structure in children with Cerebral Palsy (CP). AlterG can help CP children walk on the treadmill by reducing their weights up to 80% and maintain their balance during locomotion. AlterG training thus has the potential to improve walking capacity permanently as it can provide systematic and intense locomotor training for sufficiently long period of time and produce brain neuroplasticity. AlterG training was given for 45 minutes, three times a week for two months. The neuroplasticity of corticospinal tract was evaluated using Diffusion Tensor Imaging (DTI). The fractional Anisotropy (FA) feature was extracted to quantify structural changes of the corticospinal tract. Walking capacity was evaluated using popular clinical measurements of gait; i.e., walking speed, mobility and balance. The evaluations were done before and after training. Our results revealed that AlterG training resulted in an increase in average FA value of the corticospinal tract following the training. The outcome measures of clinical assessments of gait presented enhanced walking capacity of the CP subjects. Our findings indicated that the improved walking capacity was concurrent with the enhancement of the corticospinal tract structure. The clinical implication is that AlterG training may be considered as a therapeutic tool for permanent gait improvement in CP children.

Therapeutic effects of an anti-gravity locomotor training (AlterG) on postural balance and cerebellum structure in children with Cerebral Palsy.

We evaluated the therapeutic effects of anti-gravity locomotor treadmill (AlterG) training on postural stability in children with Cerebral Palsy (CP) and spasticity, particularly in the lower extremity. AlterG can facilitate walking by reducing the weight of CP children by up to 80%; it can also help subjects maintain an appropriate posture during the locomotor AlterG training. Thus, we hypothesized that AlterG training, for a sufficient period of time, has a potential to produce cerebellum neuroplasticity, and consequently result in an effective permanent postural stability. AlterG training was given for 45 minutes, three times a week for two months. Postural balance was evaluated using posturography. The parameters of the Romberg based posturography were extracted to quantify the Center of Balance (CoP). The neuroplasticity of Cerebellum was evaluated using a Diffusion Tensor Imaging (DTI). The evaluations were done pre- and post-training. The Fractional Anisotropy (FA) feature was used for quantifying structural changes in the cerebellum. The results showed that AlterG training resulted in an increase in average FA value of the cerebellum white matter following the training. The results of the posturography evaluations showed a consistent improvement in postural stability. These results were consistent in all subjects. Our findings indicated that the improvement in the posture was accompanied with the enhancement of the cerebellum white matter structure. The clinical implication is that AlterG training can be considered a therapeutic tool for an effective and permanent improvement of postural stability in CP children.

Therapeutic effects of an anti-gravity treadmill (AlterG) training on gait and lower limbs kinematics and kinetics in children with cerebral palsy.

We aimed to investigate the effects of the lower body weight support treadmill (AlterG) training on kinetics and kinematics of the lower extremities in children with cerebral palsy (CP). We provided a 45-minute training program, 3 times a week for 8 weeks. AlterG can support the subject's weight up to 70% so that the subject will be able to walk more comfortably to reach a more correct walking pattern. The kinematics and kinetics were evaluated using an isokinetic dynamometer. The locomotion parameters were assessed in the gait laboratory. Subjects performance was evaluated at four time points: baseline (prior to training), 1 and 2 months after the beginning of training, and one month after the end of the training (as a follow-up evaluation). The results showed that the major gait, kinematic, and kinetic parameters improved after the AlterG training and were persistent. These findings suggest that the AlterG training can be considered as a therapeutic tool for improving the lower limb performance and locomotion in children with CP.

Pendulum test measure correlates with gait parameters in children with cerebral palsy.

Individuals with cerebral palsy (CP) usually suffer from different impairments including gait impairment and spasticity. Spastic hypertonia is a defining feature of spasticity and manifests as a mechanical abnormality. The objective of this study was to determine the relationship between spastic hypertonia and gait impairments in spastic children with CP, addressing an important controversial issue. Spastic hypertonia was quantified using the pendulum test. The gait impairments were evaluated using the motion capture system in a gait laboratory. Our results showed significant correlations among gait parameters; i.e. walking speed, step length, and the pendulum test measures. This indicates that neuromuscular abnormalities are associated with spasticity and may contribute to gait impairments. The clinical implication is that the impaired gait in children with CP may be improved with the treatment of neuromuscular abnormalities.

Estimation of gait parameter using sonoelastography in children with cerebral palsy.

We aimed to study the relationship between neuromuscular abnormalities associated with spasticity and gait impairments in spastic children with hemiplegia cerebral palsy (CP). Neuromuscular abnormalities of the tibialis anterior and medial gastrocnemius muscles of the spastic ankle were quantified using sonoelastography with two major features; i.e. entropy and histogram ratio of sonoelastography images. Gait impairments were evaluated in the gait laboratory using motion capture system, and the spatial and temporal features were extracted. The correlation analysis showed a significant relation between both the entropy and histogram ratio of sonoelastography images with walking speed and step time. The findings demonstrate that the neuromuscular abnormalities associated with spasticity may contribute to gait impairments in children with CP.

Real-time tracking of laparoscopic instruments using kinect for training in virtual reality.

Training of laparoscopic surgery in Virtual Reality (VR) environment has been proved as an effective step before clinical practice. Tracking the position of instruments in realtime is an essential part of developing a VR trainer. In this study, we used Microsoft Kinect and color markers instead of using similar traditional means such as mechanical sensors. The orientation and position of instruments were determined and compared with the results obtained using the SinaSim commercial laparoscopic surgery trainer, which measures these values using encoders. The final results indicated that even though the newly developed systems possess an inferior accuracy compared to the mechanical sensors, low cost and portability makes it capable of replacing traditional methods of tracking.

Can an anti-gravity treadmill improve stability of children with cerebral palsy?

We aimed to study the effects of an anti-gravity treadmill (AlterG) training on balance and postural stability in children with cerebral palsy (CP). AlterG training was performed 3 days/week for 8 weeks, with up to 45 minutes of training per session. The subject was evaluated before and after the 8-week training. The effects of training on the balance and postural stability was evaluated based on the Romberg test that was performed by using a posturography device. The parameters quantifying Center-of-Pressure (CoP) were calculated using different analytical approaches including power spectral density and principal components analyses. All of the key parameters including the Stabilogram, the Fast Fourier Transform (FFT) Energy, the Eigenvectors, and the Eigenvalues of CoP were modified between 14%-84%. The results indicated that the balance features were improved substantially after training. The clinical implication is that the AlterG has the potential to effectively improve postural stability in children with cerebral palsy.

The correlation between transcranial magnetic stimulation parameters and neuromuscular properties in children with cerebral palsy.

We studied the correlation between corticospinal signaling and neuromuscular properties in children with Cerebral Palsy (CP). Corticospinal signaling was evaluated using Transcranial Magnetic Stimulation (TMS). Neuromuscular properties were quantified using Hoffmann reflex (H-reflex), sonoelastography, clinical measurements, and isokinetic measures. In particular, we determined the relationship between the TMS parameters of the ankle joint and the neuromuscular features of ankle extensors and flexors as well as popular clinical measures of gait speed, endurance, balance and mobility. Seventeen CP patients and twelve healthy control subjects were evaluated. Our findings showed that the motor evoked potential (MEP) latency of TMS was significantly longer in CP than in healthy subjects. The MEP-latency was significantly correlated with the H-reflex response (r=0.71, p-value=0.04) and isokinetic features; i.e. max acceleration extension time (r=0.5, p-value=0.005), and max flexion time in the cycle (r=0.5, p-value =0.002). No significant correlation was observed between MEP-latency and clinical measurements of gait and sonoelastography of ankle muscles. The results suggest that the changes in corticospinal signaling could contribute to muscle weakness and hyperexcitability of reflexes observed in children with CP.

Reciprocal inhibition becomes facilitation after spinal cord injury: clinical application of a system identification approach.

Alteration in spinal inputs from descending pathways following spinal cord injury (SCI) affects different mechanisms including reciprocal Ia inhibition. However, whether there is a consistent pattern of change in reciprocal inhibition following SCI is uncertain. Typical attempts to evaluate reciprocal inhibition have been restricted to electrophysiological measurements, which may have limited translation to function. Our objective was to address the uncertainty regarding changes in reciprocal inhibition after SCI by quantitatively evaluating reciprocal inhibition of ankle extensors from ankle flexors using our novel, more functionally relevant system identification approach. To evaluate reciprocal inhibition using the system identification technique, a series of small-amplitude PseudoRandom Binary Sequence (PRBS) perturbations were applied to the ankle when subjects contracted their dorsiflexors. Depression of reflex stiffness with tibialis anterior (TA) activation was evaluated as reciprocal inhibition. Our results showed that reflex stiffness decreased continuously as dorsiflexor torque increased in the healthy control subjects whereas it remained almost unchanged in the SCI subjects, indicating the absence of reciprocal inhibition in patients. This pattern was consistent with the results obtained from electrophysiological measures in a exploratory control experiment revealing depression of the control H-reflex but no change to the SCI H-reflex. These findings suggest that our system identification mechanical technique is a reliable and valid approach for evaluating reciprocal inhibition. Furthermore, our results demonstrate that reciprocal inhibition can diminish or change to reciprocal facilitation after SCI, which in turn can result in reflex hyperexcitability and unwanted activity of ankle extensors triggered by TA activity. This suggests that reciprocal facilitation may play a major role in pathophysiology of spasticity and impaired function.