Brain State-Dependent Closed-Loop Modulation of Paired Associative Stimulation Controlled by Sensorimotor Desynchronization

Royter, Vladislav; Gharabaghi, Alireza

doi:10.3389/fncel.2016.00115

Cited by 35 publications

(28 citation statements)

References 96 publications

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“…The spectral power range for feedback was chosen on the basis of our previous findings. These had indicated that the effective corticospinal connectivity is mediated in this frequency band (Kraus et al, 2016b, Royter and Gharabaghi, 2016, Raco et al, 2016), which also correlated with subsequent motor gains (Naros et al, 2016). Moreover, movement-related desynchronization in the ipsilesional sensorimotor cortex is compromised in stroke patients compared to healthy controls, i.e., the more severe the patient's motor impairment, the less beta-band desynchronization (Rossiter et al, 2014).…”

Section: Methodsmentioning

confidence: 98%

Plasticity of premotor cortico-muscular coherence in severely impaired stroke patients with hand paralysis

Belardinelli

Laer

Ortiz

et al. 2017

NeuroImage: Clinical

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Motor recovery in severely impaired stroke patients is often very limited. To refine therapeutic interventions for regaining motor control in this patient group, the functionally relevant mechanisms of neuronal plasticity need to be detected. Cortico-muscular coherence (CMC) may provide physiological and topographic insights to achieve this goal. Synchronizing limb movements to motor-related brain activation is hypothesized to reestablish cortico-motor control indexed by CMC.In the present study, right-handed, chronic stroke patients with right-hemispheric lesions and left hand paralysis participated in a four-week training for their left upper extremity. A brain-robot interface turned event-related beta-band desynchronization of the lesioned sensorimotor cortex during kinesthetic motor-imagery into the opening of the paralyzed hand by a robotic orthosis. Simultaneous MEG/EMG recordings and individual models from MRIs were used for CMC detection and source reconstruction of cortico-muscular connectivity to the affected finger extensors before and after the training program. The upper extremity-FMA of the patients improved significantly from 16.23 ± 6.79 to 19.52 ± 7.91 (p = 0.0015). All patients showed significantly increased CMC in the beta frequency-band, with a distributed, bi-hemispheric pattern and considerable inter-individual variability. The location of CMC changes was not correlated to the severity of the motor impairment, the motor improvement or the lesion volume. Group analysis of the cortical overlap revealed a common feature in all patients following the intervention: a significantly increased level of ipsilesional premotor CMC that extended from the superior to the middle and inferior frontal gyrus, along with a confined area of increased CMC in the contralesional premotor cortex.In conclusion, functionally relevant modulations of CMC can be detected in patients with long-term, severe motor deficits after a brain-robot assisted rehabilitation training. Premotor beta-band CMC may serve as a biomarker and therapeutic target for novel treatment approaches in this patient group.

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Section: Methodsmentioning

confidence: 98%

Plasticity of premotor cortico-muscular coherence in severely impaired stroke patients with hand paralysis

Belardinelli

Laer

Ortiz

et al. 2017

NeuroImage: Clinical

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“…It is then just a natural step to try and incorporate available models of synaptic plasticity to underpin the desired adaptive behavior of neuroprosthetic or BCI systems; the involved strategies for closed-loop, real-time hybrid system, and the associated development of "neuromorphic" chips, also have potential to possibly augment PAS, endowing them with adaptive capabilities. In the PAS domain, such options just begin to be considered (Royter et al, 2016;Sabathiel et al, 2016); in the following, to provide a hint at available methodologies to make progress towards closed-loop, adaptive PAS systems, we first briefly touch upon the present status of implementable synaptic plasticity models, and next…”

Section: Section 4: Prospects In Neuromorphic Circuitsmentioning

confidence: 99%

The associative brain at work: Evidence from paired associative stimulation studies in humans

Suppa

Quartarone

Siebner

et al. 2017

Clinical Neurophysiology

116

135

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The original protocol of Paired Associative Stimulation (PAS) in humans implies repetitive cortical and peripheral nerve stimuli, delivered at specific inter-stimulus intervals, able to elicit non-invasively long-term potentiation (LTP)- and long-term depression (LTD)-like plasticity in the human motor cortex. PAS has been designed to drive cortical LTP/LTD according to the Hebbian rule of associative plasticity. Over the last two decades, a growing number of researchers have increasingly used the PAS technique to assess cortical associative plasticity in healthy humans and in patients with movement disorders and other neuropsychiatric diseases. The present review covers the physiology, pharmacology, pathology and motor effects of PAS. Further sections of the review focus on new protocols of "modified PAS" and possible future application of PAS in neuromorphic circuits designed for brain-computer interface.

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“…The results of this study showed that for the APB muscle, corticospinal excitability after application of MI‐PAS25 was significantly increased relative to that observed after performance of MI alone. Two previous studies have shown that corticospinal excitability induced by PAS25 is increased by concurrent application of MI (Kraus, Naros, Guggenberger, Leao, & Ziemann, ; Royter & Gharabaghi, ). Although the interstimulus interval between PAS25 and MI differed (i.e., MI followed by PAS25 vs. MI and PAS25 concurrently applied), all interventional protocols produced similar effects through the associative pairing of the different stimuli.…”

Section: Discussionmentioning

confidence: 92%

Motor learning enhanced by combined motor imagery and noninvasive brain stimulation is associated with reduced short‐interval intracortical inhibition

et al. 2019

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Background Motor imagery (MI) improves motor skill learning, which is further enhanced when MI is paired with primary motor cortex transcranial brain stimulation or with electrical stimulation of the peripheral median nerve. Applying both stimulation types (here with 25 ms intervals) is called paired associative stimulation (PAS25). The final primary motor cortex output is determined by combined excitatory and intracortical inhibitory circuits, and reducing the latter is associated with enhanced synaptic transmission and efficacy. Indeed, short‐interval intracortical inhibition (SICI) inhibits motor evoked potentials (MEPs), and motor learning has been associated with decreased SICI and increased cortical excitability. Here, we investigated whether cortical excitability and SICI are altered by PAS25 applied after MI‐induced modulation of motor learning. Methods Peak acceleration of a hand‐grasping movement and MEPs and SICI were measured before and after MI alone, PAS25 alone, and MI followed by PAS25 in 16 healthy participants to evaluate changes in motor learning, corticospinal excitability, and intracortical inhibition. Results After PAS25 alone, MEP amplitude increased while peak acceleration was unchanged. However, PAS25 applied following MI not only significantly enhanced both peak acceleration (p = 0.011) and MEP amplitude (p = 0.004) but also decreased SICI (p = 0.011). Moreover, we found that this decrease in SICI was significantly correlated with both the peak acceleration (r = 0.49, p = 0.029) and the MEP amplitude (r = 0.56, p = 0.013). Conclusions These results indicate that brain function altered by PAS25 of the motor cortex enhances MI‐induced motor learning and corticospinal excitability and decreases SICI, suggesting that SICI underlies, at least in part, PAS25 modulation of motor learning.

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Brain State-Dependent Closed-Loop Modulation of Paired Associative Stimulation Controlled by Sensorimotor Desynchronization

Cited by 35 publications

References 96 publications

Plasticity of premotor cortico-muscular coherence in severely impaired stroke patients with hand paralysis

Plasticity of premotor cortico-muscular coherence in severely impaired stroke patients with hand paralysis

The associative brain at work: Evidence from paired associative stimulation studies in humans

Motor learning enhanced by combined motor imagery and noninvasive brain stimulation is associated with reduced short‐interval intracortical inhibition

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