Mechanisms of Central Motor Reorganization in Pediatric Hemiplegic Patients

Maegaki, Yoshihiro; Maeoka, Yukinori; Ishii, Shogo; Shiota, Miho; Takeuchi, Akihisa; Yoshino, Kunio; Takeshita, K

doi:10.1055/s-2007-973695

Cited by 78 publications

(43 citation statements)

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“…18 In children with congenital hemiplegia, ipsilateral connections are enhanced. 19,20 In adults with chronic stroke, their relative role is unclear although they have been associated with worse motor outcome. 21 Detection of ipsilateral pathways using functional MRI or transcranial magnetic stimulation could validate this hypothesis.…”

Section: Discussionmentioning

confidence: 99%

Corticospinal Tract Pre-Wallerian Degeneration

Domi

deVeber

Shroff

et al. 2009

Stroke

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Background and Purpose-In neonatal arterial ischemic stroke, pre-Wallerian degeneration in descending corticospinal tracts (DCST) on diffusion MRI (DWI) predicts poor outcome. This signal has not been studied in older children. Methods-A consecutive arterial ischemic stroke cohort (1 month to 18 years) with acute DWI and Ͼ12 months of follow-up were enrolled (SickKids Children's Stroke Program). DCST-DWI variables were quantified with a validated software technique and correlations to the Pediatric Stroke Outcome Measure were sought. Results-Abnormal DCST-DWI signal was detected in 20 of 29 children (69%), with 85% having motor deficits on Pediatric Stroke Outcome Measure. DCST variables correlated with hemiparesis included: (1) any abnormal signal within the course of the DCST; (2) midbrain location; (3) percentage of peduncle; (4) vertical length; and (5)

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Section: Discussionmentioning

confidence: 99%

Corticospinal Tract Pre-Wallerian Degeneration

Domi

deVeber

Shroff

et al. 2009

Stroke

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“…We propose that the more limited distal muscle motor control in older hemispherectomy subjects probably involves other subcortical mechanisms such as the cortico-reticulospinal and propriospinal inputs to the spinal cord that are less efficient than corticospinal tracts. 39 On the basis of this anatomical information, one might expect voluntary ankle dorsiflexion of each foot to be accompanied by activation within overlapping portions of S1M1, as well as adaptations induced by skills learning, such as representational expansion or increased overlap during movement of the paretic and nonparetic ankle in patients with a younger age at surgery/ injury. Our study seems to have revealed such changes.…”

Section: Discussionmentioning

confidence: 99%

Locomotor Training Remodels fMRI Sensorimotor Cortical Activations in Children After Cerebral Hemispherectomy

Bode

Mathern

Bookheimer

et al. 2007

Neurorehabil Neural Repair

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Purpose-This study examined whether locomotor training, which included body weightsupported treadmill therapy, improved walking and induced cortical representational adaptations using functional magnetic resonance imaging in the remaining sensorimotor network after cerebral hemispherectomy.Methods-Hemispherectomy patients (n = 12) under-went 2 weeks of gait training for at least 30 hours each. They were tested pre-and posttraining with the Fugl-Meyer Motor Assessment, unassisted single-limb stance time, and usual and fastest walking speeds. Three patients performed voluntary ankle movements as the functional magnetic resonance imaging activation task pre-and posttraining. Control subjects included 5 healthy children tested 2 weeks apart, 2 of whom trained on the treadmill, and 2 hemispherectomy patients who received upper extremity rehabilitation and no gait therapy.Results-Although patients reported improvements with gait training, behavioral outcomes did not significantly change. Training was associated with increased volume and intensity of cortical activation in the primary sensorimotor (S1M1), supplementary motor, motor cingulate, and secondary soma-tosensory cortex for the paretic foot, along with greater overlap in the representation for each moving foot in S1M1 and the supplementary motor area of the remaining hemisphere. Control subjects showed a decrease in activation in these cortical regions after training.Conclusions-Locomotor training of hemispherectomy patients improved mobility subjectively in association with functional magnetic resonance imaging evidence of cortical remodeling with ankle dorsiflexion. These findings support the notion that hemispherectomy patients may respond to rehabilitation interventions through mechanisms of activity-dependent cortical plasticity. The authors hypothesize that developmentally persistent descending ipsilateral and contralateral In patients with hemiparetic stroke or spinal cord trauma, recent studies support the concept that locomotor interventions can improve walking even if therapy begins years after injury. [5][6][7][8][9] The common factor that seems to lead to successful rehabilitation is repeated practice of task-related movements. 10,11 One such task-oriented intervention for walking is body weight-supported treadmill training (BWSTT). 12,13 This technique partially supports the weight of the patient to prevent the paretic leg from buckling at the knees and enables therapists to safely optimize the kinematic, kinetic, and temporal components of gait that are tied to the stance and swing phases of walking. Studies also suggest that motor gains with locomotor therapy are accompanied by cortical reorganization as observed by functional magnetic resonance imaging (fMRI). 14 For walking, fMRI during ankle dorsiflexion appears to be a good marker of training-induced cerebral plasticity. 15 The purpose of this study was to pursue these concepts in children long after hemispherectomy. We hypothesized that locomotor training that included BWSTT would be...

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“…Eventually, the contralesional hemisphere can become equipped with fast-conducting ipsilateral projections to the paretic extremities (Eyre et al 2001;Staudt et al 2002a). This type of cortico-spinal (re)organization can occur throughout the pre-and perinatal period (Staudt et al 2004), during the first months of life (Eyre et al 2007) and, in one case report, even up to the age of 2 years (Maegaki et al 1997). In children beyond this age and in adult stroke patients, such fast-conducting projections have, to date, never been reported.…”

Section: Reorganization In the Motor Systemmentioning

confidence: 95%

Reorganization after pre‐ and perinatal brain lesions*

2010

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The developing human brain can compensate for pre-and perinatally acquired focal lesions more effectively than the adult brain. The mechanisms by which this effective reorganization is achieved vary considerably between different functional systems, reflecting differences in the normal maturation of these systems. In the motor system, descending cortico-spinal motor projections have already reached their spinal target zones at the beginning of the third trimester of pregnancy, with initially bilateral projections from each hemisphere. During normal development, the ipsilateral projections are gradually withdrawn, whereas the contralateral projections persist. When, during this period, a unilateral brain lesion disrupts the cortico-spinal projections of one hemisphere, the ipsilateral projections from the contralesional hemisphere will persist. This allows the contralesional hemisphere to take over motor control over the paretic extremities. Although this mechanism of reorganization is available throughout the pre-and perinatal period, the efficacy of this ipsilateral takeover of motor functions decreases with increasing age at the time of the insult. In the somatosensory system, ascending thalamo-cortical somatosensory projections have not yet reached their cortical target zones at the beginning of the third trimester of pregnancy. Therefore, these projections can still 'react' to brain lesions acquired during this period, and can form 'axonal bypasses' around periventricular white matter lesions to reach their original cortical target areas in the postcentral gyrus. Thus, somatosensory functions can be well preserved even in cases of large periventricular lesions. In contrast, when the postcentral gyrus itself is affected, no signs for reorganization have been observed. Accordingly, somatosensory functions are often poor in these patients. Language functions can be normal even in patients with extensive early left-hemispheric brain lesions. This is achieved by language organization in the right hemisphere, which takes place in brain regions homotopic to the classical left-hemispheric language areas in normal subjects. In patients with periventricular lesions, the degree of right-hemispheric takeover of language functions correlates with the severity of structural damage to facial (and, thus, articulatory) motor projections.

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Mechanisms of Central Motor Reorganization in Pediatric Hemiplegic Patients

Cited by 78 publications

References 1 publication

Corticospinal Tract Pre-Wallerian Degeneration

Corticospinal Tract Pre-Wallerian Degeneration

Locomotor Training Remodels fMRI Sensorimotor Cortical Activations in Children After Cerebral Hemispherectomy

Reorganization after pre‐ and perinatal brain lesions*

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