Effect of observation of simple hand movement on brain activations in patients with unilateral cerebral palsy: an fMRI study

The Impact of Limited Previous Motor Experience on Action Possibility Judgments in People with Spinal Muscle Atrophy

Previous studies have shown that people with limited motor capabilities may rely on previous motor experience when making action possibility judgments for others. In the present study, we examined if having limited previous motor experience, as a consequence of spinal muscle atrophy (SMA), alters action possibility judgments. Participants with SMA and neurologically healthy (NH) sex- and age-matched controls performed a perceptual-motor judgment task using the Fitts's law paradigm. Participants observed apparent motion videos of reciprocal aiming movements with varying levels of difficulty. For each movement, participants predicted the shortest movement time (MT) at which a neurologically healthy young adult could accurately perform the task. Participants with SMA predicted significantly longer MTs compared to controls; however, the predicted MTs of both SMA and NH participants exhibited a Fitts's law relationship (i.e., the predicted MTs significantly increased as movement difficulty increased). Overall, these results provide evidence that participants with SMA who have limited, or no motor experience may make more conservative action possibility judgments for others. Critically, our finding that the pattern of action possibility judgments was not different between SMA and NH groups suggests that limited previous motor experience may not completely impair action possibility judgments.

Children with Cerebral Palsy can imagine actions like their normally developed peers

The present study aimed at assessing whether children with Cerebral Palsy (CP) can imagine object directed actions similarly to their normally developed peers. We asked children with CP (n = 12) and paired healthy controls (n = 12) to imagine in first person perspective eight daily actions, after observing them through videoclips presented on a computer screen. During motor imagery (MI) children were interrupted at a specific timepoint (e.g., at 2.5 s) from the start. Two frames extracted from the videoclips were then presented on the screen. One of the two depicted the correct timepoint at which the imagined action was interrupted, while the other represented an earlier or later timepoint. Children had to respond by pressing the key associated to the correct frame. Children also underwent VMIQ-2 questionnaire. Both groups performed similarly in the questionnaire and in the requested task, where they showed the same error rate. Errors mainly concerned the later frame, suggesting a similar strategy to solve the task in the two groups. The results support the view that children with CP can imagine actions similarly to their normally developed peers. This encourages the use of MI as a rehabilitative tool in children with motor impairment.

Effects of combat sports on cerebellar function in adolescents: a resting-state fMRI study

OBJECTIVES

To evaluate the effects of combat sports on cerebellar function in adolescents based on resting-state functional MRI (rs-fMRI).

METHODS

Rs-fMRI data were acquired from the combat sports (CS) group (n = 32, aged 14.2 ± 1.1 years) and non-athlete healthy control (HC) group (n = 29, aged 14.8 ± 0.9 years). The amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), and functional connectivity (FC) within the cerebellum was calculated and then compared between the two groups.

RESULTS

None of these participants displayed intracranial lesions on conventional MRI and microhemorrhages on SWI. Compared with the HC group, the CS group showed decreased ALFF and ReHo in the bilateral cerebellum, mainly located in the inferior regions of the cerebellum (Cerebellum_8, Cerebellum_9, Cerebellum_7b, and Cerebellum_Crus2). While increased FC was found within the cerebellar network, mainly located in the superior regions near the midline (bilateral Cerebellum_6, Cerebellum_Crus1_R, and Vermis_6). There is no internetwork FC change between the CEN and other networks.

CONCLUSION

This study confirmed extensive effects of combat sports on cerebellar rs-fMRI in adolescents, which could enhance the understanding of cerebellar regulatory mechanism under combat conditions, and provide additional information about cerebellar protective inhibition and compensatory adaptation.

ADVANCES IN KNOWLEDGE

Adolescent combat participants are an ideal model to study training-induced brain plasticity and vulnerability. Relative to task-related fMRI, rs-fMRI can bring more information about cerebellar regulation and explain the Central Governor Model more comprehensively.

From adults to pediatrics: A review noninvasive brain stimulation (NIBS) to facilitate recovery from brain injury

Stroke is a major problem worldwide that impacts over 100 million adults and children annually. Rehabilitation therapy is the current standard of care to restore functional impairments post-stroke, however its effects are limited and many patients suffer persisting functional impairments and life-long disability. Noninvasive Brain Stimulation (NIBS) has emerged as a potential rehabilitation treatment option in both adults and children with brain injury. In the last decade, Transcranial Magnetic Stimulation (TMS), Transcranial Direct Current Stimulation (tDCS) and Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) have been investigated to improve motor recovery in adults post-stroke. These promising adult findings using NIBS, however, have yet to be widely translated to the area of pediatrics. The limited studies exploring NIBS in children have demonstrated safety, feasibility, and utility of stimulation-augmented rehabilitation. This chapter will describe the mechanism of NIBS therapy (cortical excitability, neuroplasticity) that underlies its use in stroke and motor function and how TMS, tDCS, and taVNS are applied in adult stroke treatment paradigms. We will then discuss the current state of NIBS in early pediatric brain injury and will provide insight regarding practical considerations and future applications of NIBS in pediatrics to make this promising treatment option a viable therapy in children.

Effectiveness of Action Observation Training on Upper Limb Motor Function in Children with Hemiplegic Cerebral Palsy: A Systematic Review of Randomized Controlled Trials

The purpose of this review was to evaluate and examine the current best evidence for the effectiveness of action observation therapy on upper limb function rehabilitation in children with hemiplegic cerebral palsy. A comprehensive search of literature published between September 2010 and May 2020 was conducted using the following electronic databases: PubMed, Google Scholar, the Physiotherapy Evidence Database (PEDro), EMBASE, Cochrane library, and Scopus. Only randomized controlled trials evaluating the effect of action observation therapy on upper limb motor function in children with hemiplegic cerebral palsy were included. PEDro scale was used to assess the risk of bias of included trials. This study was reported according to the guideline of the PRISMA statement. The overall methodological quality of the studies was done using the PEDro scale and GRADE approach. The primary outcome measures of this review were the Melbourne Assessment Scale, Assisting Hand Assessment scale to evaluate physical function and structures. Furthermore, the ABILHAND-Kids test, and Box and Block Test primary outcome measures were used to determine the subjects’ activities and participation. Nine randomized controlled trials involving 234 participants were analyzed. The overall quality of evidence was rated from moderate to high. This review suggests action observation therapy was found to be a promising intervention for upper limb rehabilitation in children with cerebral palsy.

Brain Metabolism During A Lower Extremity Voluntary Movement Task in Children With Spastic Cerebral Palsy

Reduced selective voluntary motor control (SVMC) is a primary impairment due to corticospinal tract (CST) injury in spastic cerebral palsy (CP). There are few studies of brain metabolism in CP and none have examined brain metabolism during a motor task. Nine children with bilateral spastic CP [Age: 6-11 years, Gross Motor Function Classification System (GMFCS) Levels II-V] completed this study. SVMC was evaluated using Selective Control Assessment of the Lower Extremity (SCALE) ranging from 0 (absent) to 10 (normal). Brain metabolism was measured using positron emission tomography (PET) scanning in association with a selective ankle motor task. Whole brain activation maps as well as ROI averaged metabolic activity were correlated with SCALE scores. The contralateral sensorimotor and superior parietal cortex were positively correlated with SCALE scores (p < 0.0005). In contrast, a negative correlation of metabolic activity with SCALE was found in the cerebellum (p < 0.0005). Subsequent ROI analysis showed that both ipsilateral and contralateral cerebellar metabolism correlated with SCALE but the relationship for the ipsilateral cerebellum was stronger (R ² = 0.80, p < 0.001 vs. R ² = 0.46, p = 0.045). Decreased cortical and increased cerebellar activation in children with less SVMC may be related to task difficulty, activation of new motor learning paradigms in the cerebellum and potential engagement of alternative motor systems when CSTs are focally damaged. These results support SCALE as a clinical correlate of neurological impairment.

The relationship between neuroimaging and motor outcome in children with cerebral palsy: A systematic review - Part A. Structural imaging

BACKGROUND

Conventional Structural Magnetic Resonance Imaging (sMRI) is a mainstay in Cerebral Palsy (CP) diagnosis.

AIMS

A systematic literature review was performed with the aim to investigate the relationship between structural brain lesions identified by sMRI and motor outcomes in children with CP.

METHODS

Fifty-eight studies were included. The results were analysed in terms of population characteristics, sMRI (classified according to Krägeloh-Mann & Horber, 2007), gross and fine motor function and their interrelation.

OUTCOMES

White matter lesions were the most common brain lesion types and were present in 57.8 % of all children with uCP, in 67.0 % of all children with bCP and in 33 % of the group of mixed subtypes. Grey matter lesions were most frequently registered in children with dyskinesia (n = 42.2 %). No structural anomalies visualized by sMRI were reported in 5.7 % of all cases. In all lesion types, an equal distribution over the different gross motor function classification system categories was present. The included studies did not report sufficient information about fine motor function to relate these results to structural imaging.

CONCLUSIONS AND IMPLICATIONS

The relationship between brain structure and motor outcome needs to be further elucidated in a representative cohort of children with CP, using a more standardized MRI classification system.

Explicit Motor Imagery for Grasping Actions in Children With Spastic Unilateral Cerebral Palsy

Background: Motor Imagery (MI) refers to mental simulation of a motor action without producing any overt movement. Previous studies showed that children with Unilateral Cerebral Palsy (UCP) are impaired in implicit MI, as demonstrated by the performance of Hand Laterality Judgment tasks. The aim of this study was to examine the specificity of explicit MI deficits in UCP children. Methods: A group of UCP children (n = 10; aged 9-14) performed a mental chronometry task consisting in grasping an object and placing it into a container, or in imagining to perform the same action. As control, a group of typically developing (TD) children, matched by age, performed the same task. Movement durations for executed and imagined trials were recorded. A subgroup of 7 UCP children and 10 TD children also underwent a session of functional MRI to examine the activation of parieto-frontal areas typically associated to MI processes, during the imagination of reaching-grasping actions performed with the paretic hand. Results: Behavioral results revealed the existence of a correlation between executed and imagined movement durations both in TD and UCP groups. Moreover, the regression analysis in TD children showed that higher scores in mental chronometry tasks were positively correlated to increased bilateral activation of the intraparietal sulcus (IPS), superior parietal lobule (SPL), and dorsal premotor (PMd) cortex. A similar analysis revealed in the UCP group a positive correlation between a higher score in the mental chronometry task and bilateral activations of IPS, and to activation of contralesional, right PMd, and putamen during imagination of grasping movements. Conclusions: These results provide new insights on the relationship between MI capacity and motor deficits in UCP children, suggesting the possibility of the use of explicit MI training to improve patient's upper limb motor functions.

Mirror Neuron System Activation in Children With Unilateral Cerebral Palsy During Observation of Actions Performed by a Pathological Model

Background. Recent evidence suggested that Action Observation Therapy (AOT), based on observation of actions followed by immediate reproduction, could be a useful rehabilitative strategy for promoting functional recovery of children affected by unilateral cerebral palsy (UCP). AOT most likely exploits properties of the parieto-premotor mirror neuron system (MNS). This is more intensely activated when participants observe actions belonging to their own motor repertoire. Objective. The aim of the present study was to investigate the issue of whether MNS of UCP children is better activated by actions performed by a paretic hand rather than a healthy one. Methods. Using functional magnetic resonance imaging, we assessed brain activation in a homogeneous group of 10 right UCP children compared with that of 10 right-handed typically developing (TD) children, during observation of grasping actions performed by a healthy or a paretic hand. Results. The results revealed a significant activation within the MNS in both UCP and TD children, more lateralized to the left hemisphere in the TD group. Most important, region of interest (ROI) analysis on parietal and premotor regions showed that, in UCP, the MNS was more strongly activated by observation of actions performed by the paretic hand, a motor model more similar to the observer’s motor repertoire. Conclusions. This study shows that children affected by spastic UCP exhibit enhanced activation of the MNS during observation of goal-directed actions performed by a pathological model with respect to a healthy one.

Aberrant Interhemispheric Functional Organization in Children with Dyskinetic Cerebral Palsy

Background

Hemispheric asymmetry is one fundamental principle of neuronal organization. Interhemispheric connectivity and lateralization of intrinsic networks in the resting-state brain demonstrate the interhemispheric functional organization and can be affected by disease processes. This study aims to investigate the interhemispheric organization in children with dyskinetic cerebral palsy (DCP) based on resting-state functional MRI (fMRI).

Methods

24 children with DCP and 20 healthy children were included. Voxel-mirrored homotopic connectivity (VMHC) was calculated to detect the interhemispheric connectivity, and the lateralization of the resting-state networks was performed to examine the asymmetry of the intrinsic networks of brain.

Results

Decreased interhemispheric connectivity was found at visual, motor, and motor-control related regions in children with DCP, while high cognitive related networks including the central executive network, the frontoparietal network, and the salience network represented decreased asymmetry in children with DCP. Abnormal VMHC in visual areas, as well as the altered lateralization in inferior parietal lobule and supplementary motor area, showed correlation with the gross motor function and activities of daily living in children with DCP.

Conclusion

These findings indicate that the interhemispheric functional organization alteration exists in children with DCP, suggesting that abnormal interhemispheric interaction may be a pathophysiological mechanism of motor and cognitive dysfunction of CP.

Análise da ativação muscular durante o movimento de alcance nas condições ativo, ativo-assistido e autoassistido em pacientes pós-AVE

RESUMO O Acidente Vascular Encefálico (AVE) é uma patologia que frequentemente causa limitações motoras nos Membros Superiores (MMSS) gerando prejuízos funcionais nos movimentos de alcance. O objetivo do estudo foi analisar o recrutamento muscular do membro superior parético durante três condições de alcance: ativo, ativo-assistido e autoassistido, através de dados eletromiográficos das fibras anteriores do Músculo Deltoide (MD), Bíceps Braquial (BB) e Tríceps Braquial (TB). Estudo do tipo transversal que utilizou como testes clínicos o miniexame do estado mental, escala de equilíbrio de Berg, medida de independência funcional, escala modificada de Ashworth e escala de Fugl-Meyer - seção MMSS. A coleta dos dados eletromiográficos de superfície foi realizada utilizando-se o eletromiógrafo e eletrodos de configuração bipolar da EMG System do Brasil com três canais posicionados nos pontos motores do MD (fibras anteriores), BB e TB de ambos os membros superiores. As variáveis clínicas apresentaram resultados de comprometimento motor, cognitivo e funcional leves. Os dados eletromiográficos mostraram que o MD e TB durante o alcance ativo-assistido contraíram mais que no alcance autoassistido (p<0.05). Os MD e TB apresentaram diferenças significativas durante os movimentos de alcance, enquanto que o músculo BB não mostrou alterações. Entre os diversos tipos de alcance, o ativo-assistido foi o que proporcionou maior ativação muscular. Sugere-se que sejam feitos ensaios clínicos para verificar a eficácia dos treinamentos.

Functional Connectivity Alterations in Children with Spastic and Dyskinetic Cerebral Palsy

Cerebral palsy (CP) has long been investigated to be associated with a range of motor and cognitive dysfunction. As the two most common CP subtypes, spastic cerebral palsy (SCP) and dyskinetic cerebral palsy (DCP) may share common and distinct elements in their pathophysiology. However, the common and distinct dysfunctional characteristics between SCP and DCP on the brain network level are less known. This study aims to detect the alteration of brain functional connectivity in children with SCP and DCP based on resting-state functional MRI (fMRI). Resting-state networks (RSNs) were established based on the independent component analysis (ICA), and the functional network connectivity (FNC) was performed on the fMRI data from 16 DCP, 18 bilateral SCP, and 18 healthy children. Compared with healthy controls, altered functional connectivity within the cerebellum network, sensorimotor network (SMN), left frontoparietal network (LFPN), and salience network (SN) were found in DCP and SCP groups. Furthermore, the disconnections of the FNC consistently focused on the visual pathway; covariance of the default mode network (DMN) with other networks was observed both in DCP and SCP groups, while the DCP group had a distinct connectivity abnormality in motor pathway and self-referential processing-related connections. Correlations between the functional disconnection and the motor-related clinical measurement in children with CP were also found. These findings indicate functional connectivity impairment and altered integration widely exist in children with CP, suggesting that the abnormal functional connectivity is a pathophysiological mechanism of motor and cognitive dysfunction of CP.

Reorganization of the Action Observation Network and Sensory-Motor System in Children with Unilateral Cerebral Palsy: An fMRI Study

Little is known about the action observation network (AON) in children with unilateral cerebral palsy (UCP). Using fMRI, we aimed to explore AON and sensory-motor network (SMN) in UCP children and compare them to typically developed (TD) children and analyse the relationship between AON (re-)organization and several neurophysiological and clinical measures. Twelve UCP children were assessed with clinical scales and transcranial magnetic stimulation (TMS). For the fMRI study, they underwent a paradigm based on observation of complex and simple object-manipulation tasks executed by dominant and nondominant hand. Moreover, UCP and TD children carried out a further fMRI session to explore SMN in both an active motor and passive sensory task. AON in the UCP group showed higher lateralization, negatively related to performances on clinical scales, and had greater activation of unaffected hemisphere as compared to the bilateral representation in the TD group. In addition, a good congruence was found between bilateral or contralateral activation of AON and activation of SMN and TMS data. These findings indicate that our paradigm might be useful in exploring AON and the response to therapy in UCP subjects.

Effects of a single session of transcranial direct current stimulation on upper limb movements in children with cerebral palsy: A randomized, sham-controlled study

INTRODUCTION

Motor impairment in children with spastic hemiparetic cerebral palsy (CP) is generally more prominent in the affected upper limb, leading to limitations in hand function stemming from deficiencies in motor coordination and selective motor control as well as muscle weakness, slower execution of movements and deficient integration of sensory-motor information.

OBJECTIVE

Determine the effect of a single session of anodal transcranial direct current stimulation (tDCS) combined with functional training on the spatiotemporal variables of upper arm movements in children with spastic hemiparesis.

METHOD

A randomized, sham-controlled trial with a blinded evaluator was conducted involving 20 children with CP between 6 and 12 years of age. The spatiotemporal variables of the upper limbs were analyzed by comparing the results of Evaluation 1 (before stimulation) and Evaluation 2 (immediately after stimulation). The protocol consisted of a 20-minute session of functional training of the paretic upper limb combined with tDCS administered over the primary motor cortex of the hemisphere contralateral to the motor impairment at an intensity of 1 mA. The participants were randomly allocated to two groups: experimental group (anodal tDCS) and control group (sham tDCS).

RESULTS

Statistically significant (p < 0.05) reductions in total movement duration and returning movement duration were found in both the paretic and non-paretic limbs in the group submitted to active tDCS. No significant differences were found in the control group for any of the variables analyzed.

CONCLUSION

A single session of anodal tDCS over the primary motor cortex of the hemisphere ipsilateral to the brain lesion led to momentary motor improvements in both upper limbs of the children with spastic hemiparetic CP analyzed in the present study.

Relationship between somatosensory deficit and brain somatosensory system after early brain lesion: A morphometric study

Cerebral Palsy (CP) is a group of permanent motor disorders due to non-progressive damage to the developing brain. Poor tactile discrimination is common in children with unilateral CP. Previous findings suggest the crucial role of structural integrity of the primary (S1) and secondary (S2) somatosensory areas located in the ipsilesional hemisphere for somatosensory function processing. However, no focus on the relationship between structural characteristics of ipsilesional S1 and S2 and tactile discrimination function in paretic hands has been proposed. Using structural MRI and a two-point discrimination assessment (2 PD), we explore this potential link in a group of 21 children (mean age 13 years and 7 months) with unilateral CP secondary to a periventricular white matter injury (PWMI) or middle cerebral artery infarct (MCA). For our whole sample there was a significant negative correlation between the 2 PD and the gray matter volume in the ipsilesional S2 (rho = -0.50 95% confidence interval [-0.76, -0.08], one-tailed p-value = 0.0109) and in the ipsilesional S1 (rho = -0.57, 95% confidence interval [-0.81, -0.19], one-tailed p-value = 0.0032). When studying these relationships with regard to the lesion types, we found these correlations were non-significant in the patients with PWMI but stronger in patients with MCA. According to our results, the degree of sensory impairment is related to the spared gray matter volume in ipsilesional S1 and S2 and is marked after an MCA stroke. Our work contributes to a better understanding of why some patients with CP have variable somatosensory deficit following an early brain lesion.

Activating the motor system through action observation: is this an efficient approach in adults and children?

Observing an action performed by another person to learn a new movement is a frequent experience in adult daily life, such as in sports. However, it is an especially common circumstance during the development of motor skills in childhood. Studies on healthy humans indicate that action observation induces a facilitation in the observer's motor system. This effect is supported by an action-perception matching mechanism available both in adults and in children. Because of the simplicity of action observation, it has been proposed to apply this method in clinical contexts. After a brief, non-exhaustive introduction of the essential features underlying action observation in healthy people, we review recent studies reporting beneficial effects of rehabilitative training based on a combination of action perception and execution. We focus on therapeutic interventions for patients with upper-limb motor disabilities such as adults after stroke or children with hemiplegia due to cerebral palsy. Further, we consider data from basic science demonstrating that the facilitation induced by visual perception of the action can be modulated by the combination of multimodal stimuli related to the movement (e.g. visual and acoustic action-related inputs). In line with this, we discuss possible new directions to improve basic knowledge and therapeutic applications of action observation.

Effect of a single session of transcranial direct-current stimulation on balance and spatiotemporal gait variables in children with cerebral palsy: A randomized sham-controlled study

BACKGROUND

Transcranial direct-current stimulation (tDCS) has been widely studied with the aim of enhancing local synaptic efficacy and modulating the electrical activity of the cortex in patients with neurological disorders.

OBJECTIVE

The purpose of the present study was to determine the effect of a single session of tDCS regarding immediate changes in spatiotemporal gait and oscillations of the center of pressure (30 seconds) in children with cerebral palsy (CP).

METHOD

A randomized controlled trial with a blinded evaluator was conducted involving 20 children with CP between six and ten years of age. Gait and balance were evaluated three times: Evaluation 1 (before the stimulation), Evaluation 2 (immediately after stimulation), and Evaluation 3 (20 minutes after the stimulation). The protocol consisted of a 20-minute session of tDCS applied to the primary motor cortex at an intensity of 1 mA. The participants were randomly allocated to two groups: experimental group - anodal stimulation of the primary motor cortex; and control group - placebo transcranial stimulation.

RESULTS

Significant reductions were found in the experimental group regarding oscillations during standing in the anteroposterior and mediolateral directions with eyes open and eyes closed in comparison with the control group (p<0.05). In the intra-group analysis, the experimental group exhibited significant improvements in gait velocity, cadence, and oscillation in the center of pressure during standing (p<0.05). No significant differences were found in the control group among the different evaluations.

CONCLUSION

A single session of tDCS applied to the primary motor cortex promotes positive changes in static balance and gait velocity in children with cerebral palsy.

Effect of transcranial direct-current stimulation combined with treadmill training on balance and functional performance in children with cerebral palsy: a double-blind randomized controlled trial

Background

Cerebral palsy refers to permanent, mutable motor development disorders stemming from a primary brain lesion, causing secondary musculoskeletal problems and limitations in activities of daily living. The aim of the present study was to determine the effects of gait training combined with transcranial direct-current stimulation over the primary motor cortex on balance and functional performance in children with cerebral palsy.

Methods

A double-blind randomized controlled study was carried out with 24 children aged five to 12 years with cerebral palsy randomly allocated to two intervention groups (blocks of six and stratified based on GMFCS level (levels I-II or level III).The experimental group (12 children) was submitted to treadmill training and anodal stimulation of the primary motor cortex. The control group (12 children) was submitted to treadmill training and placebo transcranial direct-current stimulation. Training was performed in five weekly sessions for 2 weeks. Evaluations consisted of stabilometric analysis as well as the administration of the Pediatric Balance Scale and Pediatric Evaluation of Disability Inventory one week before the intervention, one week after the completion of the intervention and one month after the completion of the intervention. All patients and two examiners were blinded to the allocation of the children to the different groups.

Results

The experimental group exhibited better results in comparison to the control group with regard to anteroposterior sway (eyes open and closed; p<0.05), mediolateral sway (eyes closed; p<0.05) and the Pediatric Balance Scale both one week and one month after the completion of the protocol.

Conclusion

Gait training on a treadmill combined with anodal stimulation of the primary motor cortex led to improvements in static balance and functional performance in children with cerebral palsy.

Trial Registration

Ensaiosclinicos.gov.br/RBR-9B5DH7

Effect of motor imagery in children with unilateral cerebral palsy: fMRI study

Background

Motor imagery is considered as a promising therapeutic tool for rehabilitation of motor planning problems in patients with cerebral palsy. However motor planning problems may lead to poor motor imagery ability.

Aim

The aim of this functional magnetic resonance imaging study was to examine and compare brain activation following motor imagery tasks in patients with hemiplegic cerebral palsy with left or right early brain lesions. We tested also the influence of the side of imagined hand movement.

Method

Twenty patients with clinical hemiplegic cerebral palsy (sixteen males, mean age 12 years and 10 months, aged 6 years 10 months to 20 years 10 months) participated in this study. Using block design, brain activations following motor imagery of a simple opening-closing hand movement performed by either the paretic or nonparetic hand was examined.

Results

During motor imagery tasks, patients with early right brain damages activated bilateral fronto-parietal network that comprise most of the nodes of the network well described in healthy subjects. Inversely, in patients with left early brain lesion brain activation following motor imagery tasks was reduced, compared to patients with right brain lesions. We found also a weak influence of the side of imagined hand movement.

Conclusion

Decreased activations following motor imagery in patients with right unilateral cerebral palsy highlight the dominance of the left hemisphere during motor imagery tasks. This study gives neuronal substrate to propose motor imagery tasks in unilateral cerebral palsy rehabilitation at least for patients with right brain lesions.

The effect of video-guidance on passive movement in patients with cerebral palsy: fMRI study

In patients with cerebral palsy (CP), neuroimaging studies have demonstrated that passive movement and action-observation tasks have in common to share neuronal activation in all or part of areas involved in motor system. Action observation with simultaneous congruent passive movements may have additional effects in the recruitment of brain motor areas. The aim of this functional magnetic resonance imaging (fMRI) study was to examine brain activation in patients with unilateral CP during passive movement with and without simultaneous observation of simple hand movement. Eighteen patients with unilateral CP (fourteen male, mean age 14 years and 2 months) participated in the study. Using fMRI block design, brain activation following passive simple opening-closing hand movement of either the paretic or nonparetic hand with and without simultaneous observation of a similar movement performed by either the left or right hand of an actor was compared. Passive movement of the paretic hand performed simultaneously to the observation of congruent movement activated more "higher motor areas" including contralesional pre-supplementary motor area, superior frontal gyrus (extending to premotor cortex), and superior and inferior parietal regions than nonvideo-guided passive movement of the paretic hand. Passive movement of the paretic hand recruited more ipsilesional sensorimotor areas compared to passive movement of the nonparetic hand. Our study showed that the combination of observation of congruent hand movement simultaneously to passive movement of the paretic hand recruits more motor areas, giving neuronal substrate to propose video-guided passive movement of paretic hand in CP rehabilitation.