Altered excitation-inhibition balance in the primary sensorimotor cortex to proprioceptive hand stimulation in cerebral palsy.

OBJECTIVE: Our objective was to clarify the primary sensorimotor (SM1) cortex excitatory and inhibitory alterations in hemiplegic (HP) and diplegic (DP) cerebral palsy (CP) by quantifying SM1 cortex beta power suppression and rebound with magnetoencephalography (MEG). METHODS: MEG was recorded from 16 HP and 12 DP adolescents, and their 32 healthy controls during proprioceptive stimulation of the index fingers evoked by a movement actuator. The related beta power changes were computed with Temporal Spectral Evolution (TSE). Peak strengths of beta suppression and rebound were determined from representative channels over the SM1 cortex. RESULTS: Beta suppression was stronger contralateral to the stimulus and rebound was weaker ipsilateral to the stimulation in DP compared to controls. Beta modulation strengths did not differ significantly between HP and the control group. CONCLUSIONS: The emphasized beta suppression in DP suggests less efficient proprioceptive processing in the SM1 contralateral to the stimulation. Their weak rebound further indicates reduced intra- and/or interhemispheric cortical inhibition, which is a potential neuronal mechanism for their bilateral motor impairments. SIGNIFICANCE: The excitation-inhibition balance of the SM1 cortex related to proprioception is impaired in diplegic CP. Therefore, the cortical and behavioral proprioceptive deficits should be better diagnosed and considered to better target individualized effective rehabilitation in CP.

Functional connectivity of sensorimotor network is enhanced in spastic diplegic cerebral palsy: A multimodal study using fMRI and MEG.

OBJECTIVE: To assess the effects to functional connectivity (FC) caused by lesions related to spastic diplegic cerebral palsy (CP) in children and adolescents using multiple imaging modalities. METHODS: We used resting state magnetoencephalography (MEG) envelope signals in alpha, beta and gamma ranges and resting state functional magnetic resonance imaging (fMRI) signals to quantify FC between selected sensorimotor regions of interest (ROIs) in 11 adolescents with spastic diplegic cerebral palsy and 24 typically developing controls. Motor performance of the hands was quantified with gross motor, fine motor and kinesthesia tests. RESULTS: In fMRI, participants with CP showed enhanced FC within posterior parietal regions; in MEG, they showed enhanced interhemispheric FC between sensorimotor regions and posterior parietal regions both in alpha and lower beta bands. There was a correlation between the kinesthesia score and fronto-parietal connectivity in the control population. CONCLUSIONS: CP is associated with enhanced FC in sensorimotor network. This difference is not correlated with hand coordination performance. The effect of the lesion is likely not fully captured by temporal correlation of ROI signals. SIGNIFICANCE: Brain lesions can show as increased temporal correlation of activity between remote brain areas. We suggest this effect is likely separate from typical physiological correlates of functional connectivity.

Limb-specific thalamocortical tracts are impaired differently in hemiplegic and diplegic subtypes of cerebral palsy.

Thalamocortical pathways are considered crucial in the sensorimotor functioning of children with cerebral palsy (CP). However, previous research has been limited by non-specific tractography seeding and the lack of comparison between different CP subtypes. We compared limb-specific thalamocortical tracts between children with hemiplegic (HP, N = 15) or diplegic (DP, N = 10) CP and typically developed peers (N = 19). The cortical seed-points for the upper and lower extremities were selected (i) manually based on anatomical landmarks or (ii) using functional magnetic resonance imaging (fMRI) activations following proprioceptive-limb stimulation. Correlations were investigated between tract structure (mean diffusivity, MD; fractional anisotropy, FA; apparent fiber density, AFD) and sensorimotor performance (hand skill and postural stability). Compared to controls, our results revealed increased MD in both upper and lower limb thalamocortical tracts in the non-dominant hemisphere in HP and bilaterally in DP subgroup. MD was strongly lateralized in participants with hemiplegia, while AFD seemed lateralized only in controls. fMRI-based tractography results were comparable. The correlation analysis indicated an association between the white matter structure and sensorimotor performance. These findings suggest distinct impairment of functionally relevant thalamocortical pathways in HP and DP subtypes. Thus, the organization of thalamocortical white matter tracts may offer valuable guidance for targeted, life-long rehabilitation in children with CP.

Altered corpus callosum structure in adolescents with cerebral palsy: connection to gait and balance.

Cerebral palsy (CP) is the most common motor disorder in childhood. Recent studies in children with CP have associated weakened sensorimotor performance with impairments in the major brain white-matter (WM) structure, corpus callosum (CC). However, the relationship between CC structure and lower extremity performance, specifically gait and balance, remains unknown. This study investigated the transcallosal WM structure and lower limb motor stability performance in adolescents aged 10-18 years with spastic hemiplegic (n = 18) or diplegic (n = 13) CP and in their age-matched controls (n = 34). The modern diffusion-weighted MRI analysis included the diffusivity properties of seven CC subparts and the transcallosal lower limb sensorimotor tract of the dominant hemisphere. Children with CP had comprehensive impairments in the cross-sectional area, fractional anisotropy, and mean diffusivity of the CC and sensorimotor tract. Additionally, the extent of WM alterations varied between hemiplegic and diplegic subgroups, which was seen especially in the fractional anisotropy values along the sensorimotor tract. The diffusion properties of transcallosal WM were further associated with static stability in all groups, and with dynamic stability in healthy controls. Our novel results clarify the mechanistic role of the corpus callosum in adolescents with and without CP offering valuable insight into the complex interplay between the brain's WM organization and motor performance. A better understanding of the brain basis of weakened stability performance could, in addition, improve the specificity of clinical diagnosis and targeted rehabilitation in CP.

A test of the effort equalization hypothesis in children with cerebral palsy who have an asymmetric gait.

Healthy people can walk nearly effortlessly thanks to their instinctively adaptive gait patterns that tend to minimize metabolic energy consumption. However, the economy of gait is severely impaired in many neurological disorders such as stroke or cerebral palsy (CP). Moreover, self-selected asymmetry of impaired gait does not seem to unequivocally coincide with the minimal energy cost, suggesting the presence of other adaptive origins. Here, we used hemiparetic CP gait as a model to test the hypothesis that pathological asymmetric gait patterns are chosen to equalize the relative muscle efforts between the affected and unaffected limbs. We determined the relative muscle efforts for the ankle and knee extensors by relating extensor joint moments during gait to maximum moments obtained from all-out hopping reference test. During asymmetric CP gait, the unaffected limb generated greater ankle (1.36±0.15 vs 1.17±0.16 Nm/kg, p = 0.002) and knee (0.74±0.33 vs 0.44±0.19 Nm/kg, p = 0.007) extensor moments compared with the affected limb. Similarly, the maximum moment generation capacity was greater in the unaffected limb versus the affected limb (ankle extensors: 1.81±0.39 Nm/kg vs 1.51±0.34 Nm/kg, p = 0.033; knee extensors: 1.83±0.37 Nm/kg vs 1.34±0.38 Nm/kg, p = 0.021) in our force reference test. As a consequence, no differences were found in the relative efforts between unaffected and affected limb ankle extensors (77±12% vs 80±16%, p = 0.69) and knee extensors (41±17% vs 38±23%, p = 0.54). In conclusion, asymmetric CP gait resulted in similar relative muscle efforts between affected and unaffected limbs. The tendency for effort equalization may thus be an important driver of self-selected gait asymmetry patterns, and consequently advantageous for preventing fatigue of the weaker affected side musculature.

Stronger proprioceptive BOLD-responses in the somatosensory cortices reflect worse sensorimotor function in adolescents with and without cerebral palsy.

Cerebral palsy (CP) is a motor disorder where the motor defects are partly due to impaired proprioception. We studied cortical proprioceptive responses and sensorimotor performance in adolescents with CP and their typically-developed (TD) peers. Passive joint movements were used to stimulate proprioceptors during functional magnetic resonance imaging (fMRI) session to quantify the proprioceptive responses whose associations to behavioral sensorimotor performance were also examined. Twenty-three TD (15 females, age: mean ± standard deviation 14.2 ± 2.4 years) and 18 CP (12 females, age: mean ± standard deviation, 13.8 ± 2.3 years; 12 hemiplegic, 6 diplegic) participants were included in this study. Participants' index fingers and ankles were separately stimulated at 3 Hz and 1 Hz respectively with pneumatic movement actuators. Regions-of-interest were used to quantify BOLD-responses from the primary sensorimotor (SM1) and secondary (SII) somatosensory cortices and were compared across the groups. Associations between responses strengths and sensorimotor performance measures were also examined. Proprioceptive responses were stronger for the individuals with CP compared to their TD peers in SM1 (p < 0.001) and SII (p < 0.05) cortices contralateral to their more affected index finger. The ankle responses yielded no significant differences between the groups. The CP group had worse sensorimotor performance for hands and feet (p < 0.001). Stronger responses to finger stimulation in the dominant SM1 (p < 0.001) and both dominant and non-dominant SII (p < 0.01, p < 0.001) cortices were associated with the worse hand sensorimotor performance across all participants. Worse hand function was associated with stronger cortical activation to the proprioceptive stimulation. This association was evident both in adolescents with CP and their typically-developed controls, thus it likely reflects both clinical factors and normal variation in the sensorimotor function. The specific mechanisms need to be clarified in future studies.

The gait is less stable in children with cerebral palsy in normal and dual-task gait compared to typically developed peers.

There is limited evidence about gait stability and its alteration by concurrent motor and cognitive tasks in children with cerebral palsy (CP). We examined gait stability and how it is altered by constrained cognitive or motor task in CP and their typically developed (TD) controls. Gait kinematics were recorded using inertial-measurement units (IMU) from 18 patients with hemiplegia (13.5 ± 2.4 years), 12 with diplegia (13.0 ± 2.1 years), and 31 TD controls (13.5 ± 2.2 years) during unconstrained gait, and motor (carrying a tray) and cognitive (word naming) task constrained gait at preferred speed (~400 steps/task). Step duration, its standard deviation and refined-compound-multiscale entropy (RCME) were computed independently for vertical and resultant horizontal accelerations. Gait complexity was higher for patients with CP than TD in all tasks and directions (p < 0.001-0.01), being pronounced in vertical direction, cognitive task and for diplegic patients (p < 0.05-0.001). The gait complexity increased more (i.e. higher dual-task cost) from the unconstrained to the constrained gait in CP compared to TD (p < 0.05). Step duration was similar in all groups (p > 0.586), but its variation was higher in CP than TD (p < 0.001-0.05), and during the constrained than unconstrained gait in all groups (p < 0.01-0.001). The gait in children with CP was more complex and the dual-task cost was higher primarily for children with diplegic CP than TD during cognitive task, indicating that attentional load hinders their gait more. This raises the hypothesis that more attention and cortical resources are needed to compensate for the impaired gait in children with CP.

Soleus H-Reflex and Its Modulation With Vibration in Idiopathic Toe Walkers and Typically Developing Children.

Idiopathic toe walking is a relatively common developmental condition often leading to secondary problems such as pain and muscle contractures in the lower extremities. The cause of idiopathic toe walking is unknown, which hinders the development of treatment strategies. To test whether children with idiopathic toe walking have functional alterations in their spinal motor circuits, we studied the properties of the soleus H-reflex and its modulation with vibration in 26 idiopathic toe walkers and 16 typically developing children. At the group level, the H-reflex properties did not differ, but at the individual level, in 7 of 25 idiopathic toe walkers, some of the H-reflex parameters fell out of normal limits of typically developing children. However, the H-reflex was suppressed by vibration to the Achilles tendon similarly in both the idiopathic toe walkers and typically developing children. In conclusion, idiopathic toe walking in some children can be associated with functional alterations in their spinal motor circuits.

Multiprofessional evaluation in clinical practice: establishing a core set of outcome measures for children with cerebral palsy.

AIM: To develop a national consensus on outcome measures that define functional ability in children with cerebral palsy (CP) according to the International Classification of Functioning, Disability and Health (ICF) framework. METHOD: The project started in 2008 in neuropaediatric units of two university hospitals and one outpatient clinic. Each professional group selected representatives to be knowledge brokers for their own specialty. Based on the evidence, expert opinion, and the ICF framework, multiprofessional teams selected the most valid measures used in clinical practice (2009-2010). Data from 269 children with CP were analysed, classified by the Gross Motor Function Classification System, Manual Ability Classification System, and Communication Function Classification System, and evaluated. RESULTS: The process aimed at improving and unifying clinical practice in Finland through a national consensus on the core set of measures. The selected measures were presented by professional groups, and consensus was reached on the recommended core set of measures to be used in all hospitals treating children with CP in Finland. INTERPRETATION: A national consensus on relevant and feasible measures is essential for identifying differences in the effectiveness of local practices, and for conducting multisite intervention studies. This project showed that multiprofessional rehabilitation practices can be improved through respect for and inclusion of everyone involved.

[Riding therapy in the rehabilitation of mobility-impaired children]. / Ratsastusterapia liikuntavammaisten lasten kuntoutuksessa.

Riding therapy is a comprehensive and functional form of rehabilitation, in which the rehabilitee, the horse and the riding therapist collaborate in order to achieve individually assigned goals that support rehabilitation. In Finland, riding therapy is therapeutic rehabilitation carried out by riding therapists who have undergone approved training. The therapy is mainly implemented in an individual form, but small group working is also applied, e.g. in the form of pair therapy and therapeutic vaulting. In Europe, this form of rehabilitation has been divided into hippotherapy supporting motor functions and heilpedagogical riding therapy functioning in support of upbringing.

[Toe walking--follow or treat?]. / Varvaskävely--seurata vai hoitaa?

Idiopathic toe walking refers to continual or intermittent symmetrical gait pattern, in which the normal heel strike is lacking and the weight of the gait is on the ball of the foot. Many toe walkers are able to walk normally if they so wish. Diagnosis is established by excluding any neurological, neuromuscular, structural and orthopedic causes. Toe walkers often exhibit problems in sensory integration. Idiopathic toe walking is considered a benign phenomenon, usually self-limiting before school age, but upon becoming prolonged it may cause physical and social handicap for the child.

Does single-event multilevel surgery enhance physical functioning in the real-life environment in children and adolescents with cerebral palsy (CP)?: patient perceptions five years after surgery.

Orthopedic procedures are a method of treating gait deviations and musculoskeletal pathology that develop with age in cerebral palsy (CP). Recently single-event multilevel surgery (SEMLS) has become common practice. Although there is evidence that SEMLS could improve gait, it is unclear whether it will enhance overall physical functioning and coping strategies in the real-life environment. It is unclear how improved walking capacity affects actual functioning and enables greater independence. The aim of this study was to examine the perceptions of adolescents concerning the results of surgery on personal physical functioning in the environment five or more years after SEMLS. In this study, qualitative data were gathered by open interviews and analyzed using phenomenographic approach, which aims to study variation in human understanding and perceptions of the phenomenon in question. Gait Profile Score (GPS) was used to describe the objective change. The results indicate that SEMLS had a clear positive effect on the participants' physical functioning capacity, particularly experienced as better walking ability. GPS improved by 3.5° five years postoperatively. Surgery could enhance physical activity and the motivation to maintain mobility in the future. The perceptions of the effect of surgery on physical functioning in the real-life environment varied from a challenge-avoiding, support-seeking agency to a highly active, independent agency in daily life. Our rehabilitation practice after multilevel surgery should be more focused on enhancing active agency in collaboration with adolescents with CP and their families.

[Quantitative analysis of gait in children]. / Lasten kvantitatiivinen kävelyanalyysi.

Quantitative analysis of gait yields precise numerical data about gait. It includes three-dimensional modeling of joint movements (kinematics), analysis of reaction forces directed to the body (kinetics) as well as measurements of activation of major groups of muscles (EMG), energy consumption and pressure load on the foot. Quantitative analysis of gait and the associated clinical examination complement each other, enabling a precise and objective evaluation of gait abnormalities. Quantitative analysis of gait is suitable for patients who are more than five years old, walk independently or with walking aids, and are able to cooperate.

[Multi-level surgery of a limb improves walking ability of a CP child]. / Alaraajojen monitasokirurgia parantaa CP-vammaisen lapsen kävelykykyä.

UNLABELLED: BACKGROUND. Correction of the deformities of the lower limbs in CP children is currently attempted in one go by using multi-level surgery in one operation involving multiple procedures. MATERIAL AND METHODS. We examined from patient records the surgical outcomes and operative harms of 40 CP children operated in the HUS Department of Gynecology and Pediatrics in 2000 to 2010. Clinical examination and analysis of gait were the most important methods of assessment. RESULTS AND CONCLUSION: Most CP children benefited from the operation, with a considerable improvement in their walking posture.

Reactivity of sensorimotor oscillations is altered in children with hemiplegic cerebral palsy: A magnetoencephalographic study.

Cerebral palsy (CP) is characterized by difficulty in control of movement and posture due to brain damage during early development. In addition, tactile discrimination deficits are prevalent in CP. To study the function of somatosensory and motor systems in CP, we compared the reactivity of sensorimotor cortical oscillations to median nerve stimulation in 12 hemiplegic CP children vs. 12 typically developing children using magnetoencephalography. We also determined the primary cortical somatosensory and motor representation areas of the affected hand in the CP children using somatosensory-evoked magnetic fields and navigated transcranial magnetic stimulation, respectively. We hypothesized that the reactivity of the sensorimotor oscillations in alpha (10 Hz) and beta (20 Hz) bands would be altered in CP and that the beta-band reactivity would depend on the individual pattern of motor representation. Accordingly, in children with CP, suppression and rebound of both oscillations after stimulation of the contralateral hand were smaller in the lesioned than intact hemisphere. Furthermore, in two of the three children with CP having ipsilateral motor representation, the beta- but not alpha-band modulations were absent in both hemispheres after affected hand stimulation suggesting abnormal sensorimotor network interactions in these individuals. The results are consistent with widespread alterations in information processing in the sensorimotor system and complement current understanding of sensorimotor network development after early brain insults. Precise knowledge of the functional sensorimotor network organization may be useful in tailoring individual rehabilitation for people with CP.

Bilateral alterations in somatosensory cortical processing in hemiplegic cerebral palsy.

AIM: In individuals with cerebral palsy (CP), cerebral insults during early development may induce profound reorganization of the motor representation. This study determined the extent of alterations in cortical somatosensory functions in adolescents with hemiplegic CP with subcortical brain lesions. METHOD: We recorded somatosensory evoked magnetic fields in response to hand area stimulation from eight adolescents with hemiplegic CP (five females and three males; mean age 14y 6mo, SD 2y 3mo) and eight age- and sex-matched healthy comparison adolescents (mean age 15y 4mo, SD 2y 4mo). All participants in the CP group had purely subcortical brain lesions in magnetic resonance images. RESULTS: The somatosensory representation of the affected limb was contralateral (i.e. ipsilesional), but detailed inspection of the evoked responses showed alterations bilaterally. In the primary somatosensory cortex, the representation areas of digits II and V were in both hemispheres closer to each other in participants with CP than in comparison participants [ANOVA main effect group F(1,14) =5.58; p=0.03]. In addition, the morphology of median nerve evoked fields was altered in the participants with CP. INTERPRETATION: In hemiplegic CP, modification of the somatosensory cortical network extends beyond what would be expected based on the unilateral symptoms and the anatomical lesion. Further understanding of the functional alterations in the sensorimotor networks may aid in developing more precisely designed rehabilitation strategies.

The updated European Consensus 2009 on the use of Botulinum toxin for children with cerebral palsy.

An interdisciplinary European group of clinical experts in the field of movement disorders and experienced Botulinum toxin users has updated the consensus for the use of Botulinum toxin in the treatment of children with cerebral palsy (CP). A problem-orientated approach was used focussing on both published and practice-based evidence. In part I of the consensus the authors have tabulated the supporting evidence to produce a concise but comprehensive information base, pooling data and experience from 36 institutions in 9 European countries which involves more than 10,000 patients and over 45,000 treatment sessions during a period of more than 280 treatment years. In part II of the consensus the Gross Motor Function Measure (GMFM) and Gross Motor Function Classification System (GMFCS) based Motor Development Curves have been expanded to provide a graphical framework on how to treat the motor disorders in children with CP. This graph is named "CP(Graph) Treatment Modalities - Gross Motor Function" and is intended to facilitate communication between parents, therapists and medical doctors concerning (1) achievable motor function, (2) realistic goal-setting and (3) treatment perspectives for children with CP. The updated European consensus 2009 summarises the current understanding regarding an integrated, multidisciplinary treatment approach using Botulinum toxin for the treatment of children with CP.

Does microcurrent stimulation increase the range of movement of ankle dorsiflexion in children with cerebral palsy?

AIM: To determine whether microcurrent stimulation (MENS) increases the range of motion (ROM) of the ankle joint in children with cerebral palsy. DESIGN: Twelve children with spastic hemiplegia (age range 4.5 to 16 years) with moderate myocontracture of the triceps surae, received MENS for 1 h five times a week for 4 weeks. An equally long baseline period was preceded. The assessments were: active and passive ROM of ankle dorsiflexion, popliteal flexion and ankle dorsiflexion in maximal flexion of knees in standing position while maintaining the heels in contact with the floor, one foot standing and hopping on one foot. RESULTS: After the treatment with MENS, the passive ROM of ankle dorsiflexion with both knees flexed and extended (p<0.001) increased significantly. Increases were also observed in popliteal flexion (p<0.001) and ankle dorsiflexion (p=0.0012) during maximal flexion of the knees in a standing position. The ROM of active dorsiflexion with the knee flexed (p<0.05) and one foot standing (p<0.05) also improved. Children and parents found this treatment easy to carry out. CONCLUSIONS: MENS relieves myocontracture and can enhance conventional rehabilitation programmes for children with cerebral palsy.

Electrostimulation at sensory level improves function of the upper extremities in children with cerebral palsy: a pilot study.

The aim of this study was to evaluate the effect of electrical stimulation (ES) on the function of the upper extremities in children with cerebral palsy (CP). The participants were 12 children (seven females and five males) with spastic hemiplegia (mean age 5 years 7 months, SD 3 years 9 months). Indications were weak wrist dorsiflexion and elbow extension. The ES was given at sensory level (20-40 minutes) on the infraspinatus muscle and on the wrist dorsiflexors during 12 regularly scheduled physical and occupational therapy sessions (during 4-5 weeks). The Goal Attainment Scale, the Zancolli classification of hand function, muscle testing according to Daniels and Worthington, and King hypertonicity scale were used for evaluation. Assessments were made twice before (between 4 weeks) and twice after (between 12 weeks) the stimulation period except the King hypertonicity scale, which was used once before and 3 months after the stimulation period. Active elbow extension, wrist dorsiflexion, and forearm supination with the elbow flexed and extended improved when the results of assessments before ES were compared with those made immediately before (p<0.001) and three months after (p<0.01) this treatment. Results of this pilot uncontrolled study suggest that ES at sensory level can be used as an adjunct to physiotherapy and/or occupational therapy in children with spastic hemiplegia. These results will be used as basis for further research.

Effect of sensory-level electrical stimulation of the tibialis anterior muscle during physical therapy on active dorsiflexion of the ankle of children with cerebral palsy.

PURPOSE: The aim of the study was to determine whether add-on electrical stimulation (ES) at the sensory level improves ankle dorsiflexion in children with cerebral palsy. METHOD: Seventeen children (three to nine years of age) with spastic hemiplegia or diplegia with weak or absent active ankle dorsiflexion received ES therapy applied to the tibialis anterior muscle during ordinary scheduled physical therapy sessions for one month. The ES was given at the sensory level alone with the aim of increasing the child's sensory awareness of the voluntary movement of the ankle. RESULTS: Statistically significant improvement occurred in active ankle dorsiflexion with the knee flexed and extended between the first (pre) test and the subsequent tests (zero, two, and nine months later). Active toe flexion and extension and active inversion and eversion of the feet improved significantly. CONCLUSION: ES at the sensory level combined with physical therapy improves active and passive motion of the ankle and foot that persists months after stimulation component is removed.