Effort-induced mirror movements

Arányi, Zsuzsanna; Rösler, Kai M.

doi:10.1007/s00221-002-1101-1

Cited by 102 publications

(24 citation statements)

References 35 publications

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“…For example, some studies have reported “motor irradiation” or activation of homologous muscles of the other hand when performing various types of contractions in healthy adults (Aranyi and Rosler, 2002, Shinohara, et al, 2003). Thus, after unilateral motor cortex damage the contralesional hemisphere loses some excitation as well as inhibition due to (Carson, 2005).…”

Section: Discussionmentioning

confidence: 99%

Volumetric effects of motor cortex injury on recovery of ipsilesional dexterous movements

Darling

Pizzimenti

Hynes

et al. 2011

Experimental Neurology

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Damage to the motor cortex of one hemisphere has classically been associated with contralateral upper limb paresis, but recent patient studies have identified deficits in both upper limbs. In non-human primates, we tested the hypothesis that the severity of ipsilesional upper limb motor impairment in the early post-injury phase depends on the volume of gray and white matter damage of the motor areas of the frontal lobe. We also postulated that substantial recovery would accompany minimal task practice and that ipsilesional limb recovery would be correlated with recovery of the contralesional limb. Gross (reaching) and fine hand motor functions were assessed for 3-12 months post-injury using two motor tests. Volumes of white and gray matter lesions were assessed using quantitative histology. Early changes in post-lesion motor performance were inversely correlated with white matter lesion volume indicating that larger lesions produced greater decreases in ipsilesional hand movement control. All monkeys showed improvements in ipsilesional hand motor skill during the post-lesion period, with reaching skill improvements being positively correlated with total lesion volume indicating larger lesions were associate with greater ipsilesional motor skill recovery. We suggest that reduced trans-callosal inhibition from the lesioned hemisphere may play a role in the observed skill improvements. Our findings show that significant ipsilesional hand motor recovery is likely to accompany injury limited to frontal motor areas. In humans, more pronounced ipsilesional motor deficits that invariably develop after stroke may, in part, be a consequence of more extensive subcortical white and gray matter damage.

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Section: Discussionmentioning

confidence: 99%

Volumetric effects of motor cortex injury on recovery of ipsilesional dexterous movements

Darling

Pizzimenti

Hynes

et al. 2011

Experimental Neurology

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“…There is evidence that motor overflow is due to insufficient interhemispheric inhibition via the corpus callosum. [17][18][19] Better movement quality of females could be interpreted in two ways: first, the female brain is more capable of inhibitory processes; second, this interhemispheric inhibition is a maturational process, and females are advanced by almost 2 years in bone age and puberty. To address this, the current researchers analyzed contralateral AMs for a group of adults (n=145) at ages 45 to 55 years and found no sex difference (p=0.47).…”

Section: Discussionmentioning

confidence: 99%

Quantitative reference curves for associated movements in children and adolescents

Gasser

Rousson

Caflisch

et al. 2007

Develop Med Child Neuro

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Intensity of contralateral associated movements (AMs) is a measure of movement quality assessed using frequency and degree of AMs. A sample of 593 right-handed participants without disability (286 males, 307 females; aged 5y-18y 6mo) was studied with the Zurich Neuromotor Assessment (ZNA). The ZNA is a standardized testing procedure which assesses performance on standardized motor tasks according to timed performance and frequency and degree of AMs. In contrast to frequency and degree, intensity of AMs allowed the calculation of centiles which were quasi-continuous. Centile curves of contralateral AMs for the ZNA and data on inter-and intraobserver reliability are presented. The significance of age, sex, and side differences are discussed. Intensity of AMs offers clinical and scientific advantages for measurement of movement quality. There is a decrease of AMs with age depending on the complexity of tasks. Females showed consistently fewer AMs than males, whereas only minor side differences were shown.In children and adolescents with mild-to-moderate motor dysfunction, timed performance and movement quality for motor tasks need to be assessed reliably. Associated movements (AMs) are an important indicator of movement quality, 1,2 but good reliability is difficult to achieve. Major obstacles are standardization of assessment, scoring of AMs, and training of examiners.Various approaches have been pursued to assess AMs. The finger-lifting method requires the child to move a specified finger. [3][4][5] Using the clip-pinching method, AMs in the contralateral hand are judged when the child exhibits some pressure with the thumb and finger. 4,5 Data for AMs in motor tasks such as finger opposition, diadochokinesis, or walking on heels were also reported. These studies improved understanding of the development of movement quality. 7,8 However, they provided only qualitative, at best semi-quantitative information, and interobserver and test-retest reliability was mostly low. [9][10][11] Largo et al. presented the Zurich Neuromotor Assessment (ZNA) 12 as a standardized test battery with reference curves for timed performance. The ZNA comprises repetitive and alternating movements with hands and feet, repetitive and sequential finger movements, static and dynamic balance, diadochokinesis, and stress gaits. In a companion paper, 2 AMs were analyzed and rated according to frequency (11 levels, indicating the percentage of time with AMs) and degree (four levels, from no movement to marked movements). A normal range across age was provided, as a probability that a child exceeds some value, separately for frequency and degree. This formalization is not easy to use and interpretation of two ratings is not obvious. Centile curves, as for timed performance, were thought to be preferable. The separate rating of frequency and degree has been chosen to facilitate a standardized and accurate assessment of AMs. Thus, these two ratings were combined into one index of severity of AMs, called 'intensity of AMs', by multiplying the two. Th...

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“…Similarly, if the muscles of the active limb are progressively fatigued, there is a corresponding increase in the EMG activity recorded from the opposite limb (Arányi and Rösler, 2002). These data are consistent with the proposal that the extent of irradiation to the opposite limb is contingent upon the level of neural drive directed to the muscles engaged in the focal movement (Todor and Lazarus, 1986).…”

Section: Cross Activationmentioning

confidence: 99%

Neural pathways mediating cross education of motor function

Ruddy¹,

Carson²

2013

Front. Hum. Neurosci.

156

167

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Cross education is the process whereby training of one limb gives rise to enhancements in the performance of the opposite, untrained limb. Despite interest in this phenomenon having been sustained for more than a century, a comprehensive explanation of the mediating neural mechanisms remains elusive. With new evidence emerging that cross education may have therapeutic utility, the need to provide a principled evidential basis upon which to design interventions becomes ever more pressing. Generally, mechanistic accounts of cross education align with one of two explanatory frameworks. Models of the “cross activation” variety encapsulate the observation that unilateral execution of a movement task gives rise to bilateral increases in corticospinal excitability. The related conjecture is that such distributed activity, when present during unilateral practice, leads to simultaneous adaptations in neural circuits that project to the muscles of the untrained limb, thus facilitating subsequent performance of the task. Alternatively, “bilateral access” models entail that motor engrams formed during unilateral practice, may subsequently be utilized bilaterally—that is, by the neural circuitry that constitutes the control centers for movements of both limbs. At present there is a paucity of direct evidence that allows the corresponding neural processes to be delineated, or their relative contributions in different task contexts to be ascertained. In the current review we seek to synthesize and assimilate the fragmentary information that is available, including consideration of knowledge that has emerged as a result of technological advances in structural and functional brain imaging. An emphasis upon task dependency is maintained throughout, the conviction being that the neural mechanisms that mediate cross education may only be understood in this context.

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Effort-induced mirror movements

Cited by 102 publications

References 35 publications

Volumetric effects of motor cortex injury on recovery of ipsilesional dexterous movements

Volumetric effects of motor cortex injury on recovery of ipsilesional dexterous movements

Quantitative reference curves for associated movements in children and adolescents

Neural pathways mediating cross education of motor function

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