Role of the ipsilateral motor cortex in mirror movements.

Kanouchi, Tadashi; Yokota, Takanori; Isa, Fumiko; Ishii, Kenji; Senda, Michio

doi:10.1136/jnnp.62.6.629

Cited by 37 publications

(21 citation statements)

References 11 publications

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“…Although unaffected-side SM1 overactivation might reflect recruitment of the uncrossed corticospinal tract, its relation with mirror movements is still a matter of debate. [1][2][3][4][5]26,27 In our study, mirror movements were documented in patients 2 and 4 at PET1 and in patients 4 and 5 at PET2, but although patients 2 and 4 did show corresponding overactivations, patient 5 did not, and in addition, patient 2 still showed this overactivation despite the fact that his mirror movements had vanished. Thus, if a relationship between unaffected hemisphere SM1 overactivation and mirror movements exists, it does not appear to be systematic.…”

Section: Discussionmentioning

confidence: 71%

Dynamics of Motor Network Overactivation After Striatocapsular Stroke: A Longitudinal PET Study Using a Fixed-Performance Paradigm

Calautti¹,

Leroy²,

Guincestre³

et al. 2001

Stroke

243

189

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Background and Purpose-Although excessive brain activation during affected hand motion after stroke is well documented, its time course has been rarely studied, and when studied, this has either been with passive movement or with active but cognitively complex task and uncontrolled performance over time, complicating interpretation. Methods-According to a prospective and longitudinal design, we studied 5 right-handed patients with right-sided hemiparesis due to first-ever left striatocapsular infarction. Three-dimensional PET H 2 O 15 studies were performed twice (Ϸ7 and Ϸ31 weeks after stroke [PET1 and PET2, respectively]) during right thumb-to-index tapping executed at the same rate in both studies (1.26 Hz, auditory cued). With SPM96 software, significant group and individual overactivations (PϽ0.05, corrected for multiple comparisons) were computed by comparison with a group of 7 healthy age-matched right-handed control subjects performing the same task. Results-Motor recovery was significant from PET1 to PET2. Both the group and individual analyses revealed striking overactivations at PET1, affecting notably the cortical hand area and the whole motor network bilaterally. These overactivations were less prominent at PET2 over both hemispheres, not only in terms of Z score but also in terms of spatial extent (almost reaching statistical significance in the affected hemisphere for the latter, Pϭ0.09). However, new overactivations were found at PET2 in the left prefrontal areas, the putamen, and the premotor cortex. Conclusions-This study is the first to document that to perform the same simple movement of the paretic fingers, the brain with subcortical infarction shows less overactivations at the late than at the early timepoint, especially on the affected side, suggesting reduced recruitment of affected-hemisphere motor networks. However, unaffected-hemisphere prefrontal, premotor, and putaminal overactivations, observed at PET2 only, may suggest late-appearing compensatory reorganization. (Stroke. 2001;32:2534-2542.)

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Section: Discussionmentioning

confidence: 71%

Dynamics of Motor Network Overactivation After Striatocapsular Stroke: A Longitudinal PET Study Using a Fixed-Performance Paradigm

Calautti¹,

Leroy²,

Guincestre³

et al. 2001

Stroke

243

189

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“…7,14 In some patients with primary MM syndromes, transcranial magnetic stimulation has disclosed an increased ipsilateral hand representation in the motor cortex of each hemisphere. 34 During a hand motor task by such subjects, PET studies have found contralateral 34 or bilateral 35 motor cortex activation. Together, these data suggest that MM after adult stroke may represent an exaggeration of the degree of bilateral motor representation normally seen in adults; some patients with cerebral palsy and primary MM may also have a different mechanism underlying MM.…”

Section: Discussionmentioning

confidence: 99%

Quantitative Assessment of Mirror Movements After Stroke

Nelles

Cramer

Schaechter

et al. 1998

Stroke

127

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Background and Purpose-Mirror movements (MM) are involuntary synchronous movements of one limb during voluntary unilateral movements of the opposite limb. We measured MM in stroke and control subjects and evaluated whether MM after stroke are related to motor function. Methods-Twenty-three patients and 16 control subjects were studied. A computerized dynamometer was used during two squeezing tasks to measure intended movements from the active hand as well as MM from the opposite hand. Motor deficits were measured with the arm motor component of the Fugl-Meyer scale. Results-During paretic hand squeezing, MM in the unaffected hand were detected in 70% (repetitive squeeze) to 78%(sustained squeeze) of stroke patients. For both tasks, this was significantly (PϽ0.05) greater than the incidence of MM in the paretic hand or in either hand of control subjects (17% to 44%), except when compared with the incidence of MM in the dominant hand of control subjects (56%; Pϭ0.17). The incidence of MM in the paretic hand was not significantly different from that seen in either hand of control subjects. Patients with MM in the unaffected hand had significantly greater motor deficit than patients without MM. Patients with MM in the paretic hand had significantly better motor function than patients without MM. Conclusions-Simultaneously recording motor performances of both hands provides precise information to characterize MM. MM in the unaffected hand and in the paretic hand are associated with different degrees of motor deficit after stroke. Evaluation of MM may be useful for studying mechanisms of stroke recovery.

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“…In support of this hypothesis, when people plan a complex sequence of unilateral movements (Verstynen and Ivry 2011) or a coordinated movement of the upper and lower limbs (van den Berg et al 2011), MEPs are larger in homologous muscles of the resting hand. This spillover may arise from interhemispheric connections between homologous muscles (Kanouchi et al 1997;Kobayashi et al 2003) or the engagement of bihemispheric planning processes (Cramer et al 1999;Hanakawa et al 2005;Shibasaki et al 1993;Verstynen et al 2005). Moreover, as the complexity of movement execution increases, greater inhibition may be required to uncouple the two hands (Meyer-Lindenberg et al 2002), with failures of this form of inhibition underlying the manifestation of mirror movements (Verstynen and Ivry 2011).…”

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confidence: 99%

Inhibition during response preparation is sensitive to response complexity

Greenhouse

Saks

Hoang

et al. 2015

Journal of Neurophysiology

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Greenhouse I, Saks D, Hoang T, Ivry RB. Inhibition during response preparation is sensitive to response complexity. J Neurophysiol 113: 2792-2800, 2015. First published February 25, 2015 doi:10.1152/jn.00999.2014.-Motor system excitability is transiently suppressed during the preparation of movement. This preparatory inhibition is hypothesized to facilitate response selection and initiation. Given that demands on selection and initiation processes increase with movement complexity, we hypothesized that complexity would influence preparatory inhibition. To test this hypothesis, we probed corticospinal excitability during a delayed-response task in which participants were cued to prepare right-or left-hand movements of varying complexity. Single-pulse transcranial magnetic stimulation was applied over right primary motor cortex to elicit motor evoked potentials (MEPs) from the first dorsal interosseous (FDI) of the left hand. MEP suppression was greater during the preparation of responses involving coordination of the FDI and adductor digiti minimi relative to easier responses involving only the FDI, independent of which hand was cued to respond. In contrast, this increased inhibition was absent when the complex responses required sequential movements of the two muscles. Moreover, complexity did not influence the level of inhibition when the response hand was fixed for the trial block, regardless of whether the complex responses were performed simultaneously or sequentially. These results suggest that preparatory inhibition contributes to response selection, possibly by suppressing extraneous movements when responses involve the simultaneous coordination of multiple effectors.

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Role of the ipsilateral motor cortex in mirror movements.

Cited by 37 publications

References 11 publications

Dynamics of Motor Network Overactivation After Striatocapsular Stroke: A Longitudinal PET Study Using a Fixed-Performance Paradigm

Dynamics of Motor Network Overactivation After Striatocapsular Stroke: A Longitudinal PET Study Using a Fixed-Performance Paradigm

Quantitative Assessment of Mirror Movements After Stroke

Inhibition during response preparation is sensitive to response complexity

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