Contralateral and ipsilateral EMG responses to transcranial magnetic stimulation during recovery of arm and hand function after stroke

Turton, Ailie; Wroe, S; Trepte, N.; Fraser, Carole; Lemon, Roger

doi:10.1016/0924-980x(96)95560-5

Cited by 406 publications

(296 citation statements)

References 39 publications

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“…Therefore, the results of the present and other studies, which show an enhancement of LTP-like PASinduced plasticity, and a reduction of LTD-like plasticity by SSRIs Normann et al, 2007), make these drugs interesting substances for improving learning and motor performance in several clinical conditions (eg, in motor or speech rehabilitation after stroke). Especially with regard to stroke and depression, where LTP-like plasticity seems to be reduced, and/or LTD-like plasticity enhanced by disease-related processes (Foy et al, 1987;Schaechter, 2004;Traversa et al, 1997;Traversa et al, 1998;Turton et al, 1996;Xu et al, 1997), the results of the present study can at least partially explain why SSRIs can reduce symptoms.…”

Section: General Remarksmentioning

confidence: 57%

Effect of Serotonin on Paired Associative Stimulation-Induced Plasticity in the Human Motor Cortex

Batsikadze

Paulus

Kuo

et al. 2013

Neuropsychopharmacol

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Serotonin modulates diverse brain functions. Beyond its clinical antidepressant effects, it improves motor performance, learning and memory formation. These effects might at least be partially caused by the impact of serotonin on neuroplasticity, which is thought to be an important foundation of the respective functions. In principal accordance, selective serotonin reuptake inhibitors enhance long-term potentiation-like plasticity induced by transcranial direct current stimulation (tDCS) in humans. As other neuromodulators have discernable effects on different kinds of plasticity in humans, here we were interested to explore the impact of serotonin on paired associative stimulation (PAS)-induced plasticity, which induces a more focal kind of plasticity, as compared with tDCS, shares some features with spike timing-dependent plasticity, and is thought to be relative closely related to learning processes. In this single-blinded, placebo-controlled, randomized crossover study, we administered a single dose of 20 mg citalopram or placebo medication and applied facilitatory-and excitability-diminishing PAS to the left motor cortex of 14 healthy subjects. Cortico-spinal excitability was explored via single-pulse transcranial magnetic stimulation-elicited MEP amplitudes up to the next evening after plasticity induction. After citalopram administration, inhibitory PAS-induced after-effects were abolished and excitatory PAS-induced after-effects were enhanced trendwise, as compared with the respective placebo conditions. These results show that serotonin modulates PAS-induced neuroplasticity by shifting it into the direction of facilitation, which might help to explain mechanism of positive therapeutic effects of serotonin in learning and medical conditions characterized by enhanced inhibitory or reduced facilitatory plasticity, including depression and stroke.

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Section: General Remarksmentioning

confidence: 57%

Effect of Serotonin on Paired Associative Stimulation-Induced Plasticity in the Human Motor Cortex

Batsikadze

Paulus

Kuo

et al. 2013

Neuropsychopharmacol

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“…[33••,42]). Perhaps then, the difference between some conditions of motor deficit and motor skill is simply a matter of the number of available muscle synergies and the appropriateness of those muscle synergies [43,44].…”

Section: Muscle Synergiesmentioning

confidence: 99%

Neuromechanics of muscle synergies for posture and movement

Ting

McKay

2007

Current Opinion in Neurobiology

381

251

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Recent research suggests that the nervous system controls muscles by activating flexible combinations of muscle synergies to produce a wide repertoire of movements. Muscle synergies are like building blocks, defining characteristic patterns of activation across multiple muscles that may be unique to each individual, but perform similar functions. The identification of muscle synergies has strong implications for the organization and structure of the nervous system, providing a mechanism by which task-level motor intentions are translated into detailed, low-level muscle activation patterns. Understanding the complex interplay between neural circuits and biomechanics that give rise to muscle synergies will be critical to advancing our understanding of neural control mechanisms for movement.

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“…Transcranial magnetic stimulation (TMS) has gained considerable acceptance as a method to non-invasively study adaptive changes in motor cortex as a consequence of repeated practice or learning in able-bodied individuals (e.g., Tinazzi and Zanette 1998) and as a consequence of injury in individuals who have suffered strokes, limb amputation and spinal cord injury (e.g., Turton et al 1996;Liepert et al 1998;Capaday et al 2000;Park et al 2004). For example, effects of some rehabilitation techniques following brain injury have been evaluated by estimating the motor cortical area that is responsive to suprathreshold stimulation of a muscle of interest (e.g., Liepert et al 1998).…”

Section: Introductionmentioning

confidence: 99%

Variability of motor potentials evoked by transcranial magnetic stimulation depends on muscle activation

2006

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The purpose of this research was to determine whether motor cortex excitability assessed using transcranial magnetic stimulation (TMS) is less variable when subjects maintain a visually controlled low-level contraction of the muscle of interest. We also examined the dependence of single motor evoked potential (MEP) amplitude on stimulation intensity and pre-stimulus muscle activation level using linear and non-linear multiple regression analysis. Eight healthy adult subjects received single pulse TMS over the left motor cortex at a point where minimal stimulation intensity was required to produce MEPs in extensor digitorum communis (EDC). Voluntary activation of the muscle was controlled by visual display of a target force (indicated by a stable line on an oscilloscope) and the isometric force produced as the subject attempted to extend the fingers (indicated by a line on the oscilloscope representing the finger extension force) while subjects were instructed to: exert zero extension force (0%) and produce forces equal to 5 and 10% of maximum voluntary finger extension under separate conditions. Relative variability (coefficient of variation) of single MEPs at a constant stimulus intensity and of pre-stimulus muscle EMG was lower during maintained 5 and 10% contractions than at 0% contraction levels. Therefore, maintaining a stable low intensity contraction helps stabilize cortical and spinal excitability. Multiple regression analyses showed that a linear dependence of single MEPs on stimulation intensity and pre-stimulus muscle activation level produced similar fits to those for a non-linear dependence on stimulus intensity and a linear dependence on pre-stimulus EMG. Thus, a simple linear method can be used to assess dependence of single MEP amplitudes on both stimulus intensity (to characterize slope of the recruitment curve) and low intensity background muscle activation level.

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Contralateral and ipsilateral EMG responses to transcranial magnetic stimulation during recovery of arm and hand function after stroke

Cited by 406 publications

References 39 publications

Effect of Serotonin on Paired Associative Stimulation-Induced Plasticity in the Human Motor Cortex

Effect of Serotonin on Paired Associative Stimulation-Induced Plasticity in the Human Motor Cortex

Neuromechanics of muscle synergies for posture and movement

Variability of motor potentials evoked by transcranial magnetic stimulation depends on muscle activation

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