Transcranial Magnetic Stimulation: A Primer

Hallett, Mark

doi:10.1016/j.neuron.2007.06.026

Cited by 1,486 publications

(1,223 citation statements)

References 118 publications

Supporting

Mentioning

1,186

Contrasting

Unclassified

Order By: Relevance

“…rTMS has been used extensively to manipulate the excitability of motor cortical structures, including M1. Highfrequency (Ͼ1 Hz) rTMS tends to increase corticospinal excitability, and low-frequency rTMS (Յ1 Hz) administered below, at, and above resting motor threshold (rMT) tends to decrease corticospinal excitability that can last for up to an hour after the stimulation is stopped (26,45). Even highfrequency magnetic brain stimulation in the form of continuous magnetic theta-burst stimulation, when administered after voluntary contractions, can depress corticospinal excitability (21).…”

mentioning

confidence: 99%

Chronic low-frequency rTMS of primary motor cortex diminishes exercise training-induced gains in maximal voluntary force in humans

Hortobágyi¹,

Richardson²,

Lomarev³

et al. 2009

Journal of Applied Physiology

Self Cite

View full text Add to dashboard Cite

Hortobágyi T, Richardson SP, Lomarev M, Shamim E, Meunier S, Russman H, Dang N, Hallett M. Chronic low-frequency rTMS of primary motor cortex diminishes exercise training-induced gains in maximal voluntary force in humans. J Appl Physiol 106: 403-411, 2009. First published November 13, 2008 doi:10.1152/japplphysiol.90701.2008Although there is consensus that the central nervous system mediates the increases in maximal voluntary force (maximal voluntary contraction, MVC) produced by resistance exercise, the involvement of the primary motor cortex (M1) in these processes remains controversial. We hypothesized that 1-Hz repetitive transcranial magnetic stimulation (rTMS) of M1 during resistance training would diminish strength gains. Forty subjects were divided equally into five groups. Subjects voluntarily (Vol) abducted the first dorsal interosseus (FDI) (5 bouts ϫ 10 repetitions, 10 sessions, 4 wk) at 70 -80% MVC. Another group also exercised but in the 1-min-long interbout rest intervals they received rTMS [VolϩrTMS, 1 Hz, FDI motor area, 300 pulses/ session, 120% of the resting motor threshold (rMT)]. The third group also exercised and received sham rTMS (VolϩSham). The fourth group received only rTMS (rTMS_only). The 37.5% and 33.3% gains in MVC in Vol and VolϩSham groups, respectively, were greater (P ϭ 0.001) than the 18.9% gain in VolϩrTMS, 1.9% in rTMS_only, and 2.6% in unexercised control subjects who received no stimulation. Acutely, within sessions 5 and 10, single-pulse TMS revealed that motor-evoked potential size and recruitment curve slopes were reduced in VolϩrTMS and rTMS_only groups and accumulated to chronic reductions by session 10. There were no changes in rMT, maximum compound action potential amplitude (M max), and peripherally evoked twitch forces in the trained FDI and the untrained abductor digiti minimi. Although contributions from spinal sources cannot be excluded, the data suggest that M1 may play a role in mediating neural adaptations to strength training. muscle; transcranial magnetic stimulation; cortical excitability IT IS WELL ESTABLISHED that neural mechanisms mediate the initial gains in maximal voluntary strength in response to chronic resistance exercise (9,16,19,20,39). However, there is disagreement concerning the magnitude and nature of involvement of specific structures of the central nervous system in neuronal adaptations to chronic exercise. A handful of studies used transcranial magnetic stimulation (TMS) to determine whether the primary motor cortex (M1) contributes to neuronal adaptations to resistance training-induced increases in voluntary force (9,25,30). Carroll et al. (9) found that resistance training did not modify the size of the TMSproduced motor-evoked potentials (MEPs) at rest, but the force of the first dorsal interosseus muscle (FDI) at which maximum MEP amplitude occurred significantly shifted from ϳ50% maximal voluntary force (maximal voluntary contraction, MVC) before training to ϳ35% MVC after training. Coupled with data produced by transcranial ele...

show abstract

mentioning

confidence: 99%

Chronic low-frequency rTMS of primary motor cortex diminishes exercise training-induced gains in maximal voluntary force in humans

Hortobágyi¹,

Richardson²,

Lomarev³

et al. 2009

Journal of Applied Physiology

Self Cite

View full text Add to dashboard Cite

show abstract

“…TMS is a means of stimulating a specific cortical area non-invasively by delivering pulses of magnetic stimulation using a coil placed directly above the area of interest. The pulse excites cortical neurons underneath the coil (Hallett, 2007) and by recording the cortical response using EEG, the method allows direct examination of the influence of this stimulation on cortical connectivity while other influences are under experimental control (Lee et al, 2003;Massimini et al, 2005). TMS was applied to two different cortical areas across six participants in wakefulness and NREM sleep.…”

Section: Effective Connectivity Studiesmentioning

confidence: 99%

What Is Lost During Dreamless Sleep: The Relationship Between Neural Connectivity Patterns and Consciousness

Klímová

2014

Journal of European Psychology Students

View full text Add to dashboard Cite

Non-rapid eye movement (NREM) sleep is characterised by reduced consciousness; thus, studying its neural characteristics acts as a useful indication of what is needed for conscious experience. The integrated information theory (Tononi, 2008) states that the ability of different thalamocortical regions to interact is crucial for consciousness, thereby motivating research concerning connectivity changes in the thalamocortical system that accompany changing consciousness levels. This review aims to discuss investigations of functional connectivity of resting-state and large-scale brain networks, applying correlational approaches to neuroimaging data as well as studies that used brain stimulation to investigate effective connectivity. Most findings suggest a reorganisation of functional brain networks where interregion connectivity is reduced and intra-region connectivity is stronger in deep sleep than wakefulness.

show abstract

“…Two stimuli are given, a short period apart (typically 0-20 ms) [15,42,54], over the motor cortex. Often, the positioning of the TMS coil is such that an electromyogram (EMG) response can be detected at the wrist.…”

Section: Acute Effects Of Tmsmentioning

confidence: 99%

“…The rapidly changing magnetic field induces electrical currents within the cortex and stimulates activity over a wide area (a few cm 2 ) within the brain [50]. TMS has had various reports of success in rehabilitation of stroke patients and in treating Parkinson's disease [35,15,10]; however, a recent study on rehabilitation of stroke patients did not find any clinical significance in applying TMS as part of treatment [47]. TMS has also been applied in slow wave sleep to increase the numbers of slow waves occuring, and while a useful tool for probing the structure of sleep [28] it is unclear as to whether TMS has any clinical significance with regard treatment of sleep disorders [6].…”

Section: Introductionmentioning

confidence: 99%

Numerical modelling of plasticity induced by transcranial magnetic stimulation

et al. 2013

View full text Add to dashboard Cite

We use neural field theory and spike-timing dependent plasticity to make a simple but biophysically reasonable model of long-term plasticity changes in the cortex due to transcranial magnetic stimulation (TMS). We show how common TMS protocols can be captured and studied within existing neural field theory. Specifically, we look at repetitive TMS protocols such as theta burst stimulation and paired-pulse protocols. Continuous repetitive protocols result mostly in depression, but intermittent repetitive protocols in potentiation. A paired pulse protocol results in depression at short (<∼ 10 ms) and long (>∼ 100 ms) interstimulus intervals, but potentiation for mid-range intervals. The model is sensitive to the choice of neural populations that are driven by the TMS pulses, and to the parameters that describe plasticity, which may aid interpretation of the high variability in existing experimental results. Driving excitatory populations results in greater plasticity changes than driving inhibitory populations. Modelling also shows the merit in optimizing a TMS protocol based on an individual's electroencephalogram. Moreover, the model can be used to make predictions about protocols that may lead to improvements in repetitive TMS outcomes.

show abstract

Transcranial Magnetic Stimulation: A Primer

Cited by 1,486 publications

References 118 publications

Chronic low-frequency rTMS of primary motor cortex diminishes exercise training-induced gains in maximal voluntary force in humans

Chronic low-frequency rTMS of primary motor cortex diminishes exercise training-induced gains in maximal voluntary force in humans

What Is Lost During Dreamless Sleep: The Relationship Between Neural Connectivity Patterns and Consciousness

Numerical modelling of plasticity induced by transcranial magnetic stimulation

Contact Info

Product

Resources

About