250 research outputs found
On the Use of Metaanalysis in Neuromodulatory Non-invasive Brain Stimulation
No full textWellcome Trust [091593
Consensus paper: Combining trascranial stimulation with neuroimaging (vol 2, pg 58, 2009)
No full textErratum to ‘Consensus paper: Combining trascranial
stimulation with neuroimaging’ [Brain Stimulation 2(2):58-
80]
Hartwig R. Siebner Til O. Bergmann, Sven Bestmann,
Marcello Massimini, Heidi Johansen-Berg, Hitoshi Mochizuki,
Daryl E. Bohning, Erie D. Boorman, Sergiu Groppa,
Carlo Miniussi, Alvaro Pascual-Leone, Reto Huber, Paul
C.J. Taylor, Risto J. Ilmoniemi, Luigi De Gennaro, Antonio
P. Strafella, Seppo Ka ̈hko ̈nen, Stefan Klo ̈ppel, Giovanni B.
Frisoni, Mark S. George, Mark Hallett, Stephan A. Brandt,
Matthew F. Rushworth, Ulf Ziemann, John C. Rothwell,
Nick Ward, Leonardo G. Cohen, Ju ̈rgen Baudewig, Toma ́sˇ
Paus, Yoshikazu Ugawa, Paolo M. Rossini
The publisher regrets that some of the authors’ degrees
were listed incorrectly in the above mentioned paper.
Please see corrected list below:
Hartwig R. Siebner, MD, Til O. Bergmann, MSc, Sven
Bestmann, PhD, Marcello Massimini, MD, PhD, Heidi
Johansen-Berg, PhD, Hitoshi Mochizuki, MD, PhD, Daryl
E. Bohning, PhD, Erie D. Boorman, MSc, Sergiu Groppa,
MD, Carlo Miniussi, PhD, Alvaro Pascual-Leone, MD,
PhD, Reto Huber, PhD, Paul C.J. Taylor, PhD, Risto J.
Ilmoniemi, PhD, Luigi De Gennaro, PhD, Antonio P.
Strafella, MD, PhD, Seppo Ka ̈hko ̈nen, MD, PhD, Stefan
Klo ̈ppel, MD, Giovanni B. Frisoni, MD, Mark S. George,
MD, Mark Hallett, MD, Stephan A. Brandt, MD, PhD,
Matthew F. Rushworth, PhD, Ulf Ziemann, MD, John C.
Rothwell, PhD, Nick Ward, MD, PhD, Leonardo G. Cohen,
MD, Ju ̈ rgen Baudewig, PhD, Toma ́sˇ Paus, MD, PhD
Muscle and Timing-specific Functional Connectivity between the Dorsolateral Prefrontal Cortex and the Primary Motor Cortex
No full textThe pFC has a crucial role in cognitive control, executive function, and sensory processing. Functional imaging, neurophysiological, and animal studies provide evidence for a functional connectivity between the dorsolateral pFC (DLPFC) and the primary motor cortex (M1) during free choice but not instructed choice selection tasks. In this study, twin coil, neuro-navigated TMS was used to examine the precise timing of the functional interaction between human left DLPFC and ipsilateral M1 during the execution of a free/specified choice selection task involving the digits of the right hand. In a thumb muscle that was not involved in the task, a conditioning pulse to the left DLPFC enhanced the excitability of the ipsilateral M1 during free selection more than specified selection 100 msec after presentation of the cue; the opposite effect was seen at 75 msec. However, the difference between free and externally specified conditions disappeared when a task-specific muscle was investigated. In this case, the influence from DLPFC was dominated by task involvement rather than mode of selection, suggesting that other processes related to movement execution were also operating. Finally, we show that the effects were spatially specific because they were absent when an adjacent area of DLPFC was stimulated. These results reveal temporally and spatially selective interactions between BA 46 and M1 that are both task and muscle specific
Neurophysiological investigations in patients with primary writing tremor
No full textThe pathophysiology of primary writing tremor (PWT) is still unknown: it has been classified as a focal form of essential tremor and as a tremulous form of writer’s cramp. We studied cortical and spinal excitability in patients with PWT and compared the results with published data of patients with essential tremor, and writer’s cramp. We used electrical stimulation of median and radial nerve to study reciprocal inhibition of forearm antagonist muscles and paired transcranial magnetic stimulation at short and long interstimulus intervals (ISIs) to assess intracortical excitability. Both studies were conducted on patients with PWT and on control subjects. The early (presynaptic) and late (disynaptic) phases of reciprocal inhibition were normal as was intracortical excitability at short and long ISIs. Our study suggests that the pathophysiology of PWT is different from that of writer’s cramp and partially also from that of essential tremor
Muscle and Timing-specific Functional Connectivity between the Dorsolateral Prefrontal Cortex and the Primary Motor Cortex
No full textThe pFC has a crucial role in cognitive control, executive function, and sensory processing. Functional imaging, neurophysiological, and animal studies provide evidence for a functional connectivity between the dorsolateral pFC (DLPFC) and the primary motor cortex (M1) during free choice but not instructed choice selection tasks. In this study, twin coil, neuro-navigated TMS was used to examine the precise timing of the functional interaction between human left DLPFC and ipsilateral M1 during the execution of a free/specified choice selection task involving the digits of the right hand. In a thumb muscle that was not involved in the task, a conditioning pulse to the left DLPFC enhanced the excitability of the ipsilateral M1 during free selection more than specified selection 100 msec after presentation of the cue; the opposite effect was seen at 75 msec. However, the difference between free and externally specified conditions disappeared when a task-specific muscle was investigated. In this case, the influence from DLPFC was dominated by task involvement rather than mode of selection, suggesting that other processes related to movement execution were also operating. Finally, we show that the effects were spatially specific because they were absent when an adjacent area of DLPFC was stimulated. These results reveal temporally and spatially selective interactions between BA 46 and M1 that are both task and muscle specific
Cortical correlates of TMS-induced phantom hand movements revealed with concurrent TMS-fMRI
No full textWe studied an amputee patient who experiences a conscious sense of movement (SoM) in her phantom hand, without significant activity in remaining muscles, when transcranial magnetic stimulation (TMS) is applied at appropriate intensity over the corresponding sector of contralateral motor cortex. We used the novel methodological combination of TMS during fMRI to reveal the neural correlates of her phantom SoM. A critical contrast concerned trials at intermediate TMS intensities: low enough not to produce overt activity in remaining muscles; but high enough to produce a phantom SoM on approximately half such trials. Comparing trials with versus without a phantom SoM reported phenomenally, for the same intermediate TMS intensities, factored out any non-specific TMS effects on brain activity to reveal neural correlates of the phantom SoM itself. Areas activated included primary motor cortex, dorsal premotor cortex, anterior intraparietal sulcus, and caudal supplementary motor area, regions that are also involved in some hand movement illusions and motor imagery in normals. This adds support to proposals that a conscious sense of movement for the hand can be conveyed by activity within corresponding motor-related cortical structures. (c) 2006 Elsevier Ltd. All rights reserved.Medical Research Council [G0500784]; Wellcome Trus
High-dose high-intensity Queen Square upper-limb rehabilitation for people with chronic stroke (INTENSIVE): protocol for a single-centre, randomised controlled trial
No full textIntroduction There is currently insufficient high-quality evidence to make general recommendations about high-dose high-intensity upper-limb rehabilitation programmes. Here we describe a randomised controlled trial that will determine the efficacy of two forms of high-dose, high-intensity upper-limb rehabilitation provided in a rehabilitation unit setting.Methods and analysis Patients with moderate upper-limb impairment (n=105, at least 6 months after stroke) will be randomised to either (1) high-dose high-intensity conventional upper-limb rehabilitation, (2) high-dose high-intensity virtual reality-based upper-limb rehabilitation and (3) usual care (a waiting list control group). Groups 1 and 2 will receive a minimum of 45 hours of active time on task over 3 weeks. Outcome measures will be collected at (T1) baseline; (T2) immediately post intervention and (T3) 3 months after the intervention has finished. The primary outcome measure will be the Fugl-Meyer Upper Extremity Assessment at 3 months after the intervention. Secondary outcome measures will be clinical, kinematic and neurophysiological using transcranial magnetic stimulation and electroencephalography. Explanatory measures will include MRI-based markers for integrity of the corticospinal tract, dorsal column-medial lemniscal pathway, grey and white matter and lesion load. The aim is to detect a difference of 7.25 points on the Fugl-Meyer Upper Extremity Assessment between each treatment group and the waitlist control group, with a power of 0.9 and significance of 0.025 (to account for two primary analyses). Analysis of change in the primary and secondary outcome measures will be performed using mulitple regression analysis.Ethics and dissemination The study protocol (V.1) has been approved by the Wales Research Ethics Committee 2 Cardiff (Rec reference: 22/WA/0065) on 15 March 2022. All recruited participants will provide informed consent. Trial results will be disseminated through peer-reviewed publications, presentations at major stroke/neurorehabilitation conferences and outreach to relevant stakeholder communities.Trial registration number NCT05527262.This study is sponsored by the Joint Research Office at University College London: Mr Pushpsen Joshi. The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article. This research was funded by the Stroke Association grant (Dr LTT- SA PDF 20\100007). The views expressed are those of the author(s) and not necessarily those of the funder. This research is also funded by the Jon Moulton Charity Trust
Functional MRI of cortical activations induced by transcranial magnetic stimulation (TMS).
No full textThe effects of repetitive transcranial magnetic stimulation (rTMS) on human brain activity and associated hemodynamics were investigated by blood-oxygenation-level-dependent (BOLD) MRI using echo-planar imaging at 2.0 T. Apart from bilateral activation of the auditory cortex by the audible rTMS discharges (23 bursts, 1 s duration, 10 Hz, 10-20 s interstimulus intervals), BOLD responses were restricted to cortical representations of actual finger movements performed either voluntarily or evoked by suprathreshold rTMS of the motor cortex. Neither subthreshold rTMS of the motor cortex nor suprathreshold rTMS of the lateral premotor cortex induced a detectable BOLD response. These findings suggest that neuronal depolarization as induced by rTMS modulates the spiking output of a brain area but does not automatically alter cerebral blood flow and oxygenation. The observation of BOLD MRI activations probably reflects the afferent intracortical processing of real movements. (C) 2001 Lippincott Williams & Wilkins
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