Insights into motor learning from a viewpoint of transcranial magnetic stimulation

Several protocols of non-invasive transcranial magnetic stimulation have been developed in the past decades. Single-and paired-pulse transcranial magnetic stimulation are painless, and noninvasive tools to evaluate cortical and corticospinal excitability in cerebral cortex compared with transcranial electric stimulation. Motor evoked potential induced by paired-pulse transcranial magnetic stimulation can particularly assess changes of the cortical excitability after motor learning, such as motor skill and motor practice in sports and functional recovery in rehabilitation. However, the effect of electric current in transcranial magnetic stimulation on pyramidal neuron and interneuron in gray and white matters is not actually understood well yet in the field of sports and rehabilitation sciences. Here, we show the important basic knowledge of neurophysiology and transcranial magnetic stimulation and introduce some studies of cortical plasticity and motor learning by using transcranial magnetic stimulation

Transcranial magnetic stimulation

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenTranscranial Magnetic Stimulation (TMS) is a new non-invasive method to investigate the central nervous system. Initially it was used to assess the functional integrity of the pyramidal pathways but more recently various other aspects of brain function have been studied including cortical excitability. By localised interference with brain function, it is possible to use TMS to assess the relationship between various brain regions and cognitive functions. The therapeutic effect of TMS has been explored in the treatment of neurological diseases and psychiatric disorders such as epilepsy, cerebellar ataxia and depressive illness.Segulörvun heila í gegnum höfuðkúpu er notuð til rannsókna á miðtaugakerfi. Upphaflega var þessi aðferð þróuð til að meta starfsemi og ástand hreyfitauga­brauta milli heila og mænu, en er nú einnig notuð til margvíslegra rannsókna á heilastarfsemi. Meta má hömlunar- og örvunarástand heilabarkar sem getur breyst vegna heilasjúkdóma og við lyfjagjöf. Með staðbundinni truflun á starfsemi taugafrumna eftir segulörvun hefur verið hægt að kanna tengsl milli heilasvæða og hugrænna ferla. Í ljós hefur komið möguleg notkun segulörvunar í meðferð taugasjúkdóma og geðraskana. Rannsóknir hvað þetta varðar hafa meðal annars beinst að flogaveiki, mænu- og hnykilhrörnun og djúpri geðlægð

Neuroethical Considerations Regarding Transcranial Magnetic Stimulation

Along with advances in brain technologies comes the ability to enhance the cognitive and affective states of normal people. In this essay, I examine a relatively young technology used in cognitive neuroscience called transcranial magnetic stimulation (TMS). I explain what it is, how it works and what some of its applications are. I suggest that a potential source of reservation one might have regarding brain-altering enhancement is the threat it seemingly poses to the subjective importance of mental states. I then consider the possibility of its being used as an enhancement device and question the authenticity of abilities of individuals that are enhanced by use of TMS. I conclude that judgments regarding the appropriateness of such neurocognitive enhancements should be considered on a case by case basis

Transcranial magnetic stimulation as a new tool to control pain perception.

Treatment for chronic pain is frequently unsuccessful or characterized by side-effects. The high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) has been suggested in the management of refractory chronic pain. Various studies have shown that HF-rTMS sessions of long-duration applied at primary motor cortex induce pain relief through mechanisms of plastic changes. Efficacy of rTMS mostly depends on stimulation parameters, but this aspect requires better characterization. A rationale to target other cortical areas exists. Current data are promising, but a careful analysis of stimulation settings and maintenance treatment design are need

Immediate impact of transcranial magnetic stimulation on brain structure: short-term neuroplasticity following one session of cTBS

Recent evidence demonstrates that activation-dependent neuroplasticity on a structural level can occur in a short time (2 hour or less) in humans. However, the exact time scale of structural plasticity in adult human brain remains unclear. Using voxel-based morphometry (VBM), we investigated changes in gray matter (GM) after one session of continuous theta-burst stimulation (cTBS) delivered to the anterior temporal lobe (ATL). Twenty-five participants were received cTBS over the left ATL or occipital pole as a control site outside of the scanner and had structural and functional imaging. During functional imaging, participants performed a semantic association task. VBM result revealed decreased GM in the left ATL and right cerebellum after ATL stimulation compared to the control stimulation. In addition, cTBS over the left ATL induced slower reaction time in sematic task performance, reduced regional activity at the target site, and altered functional connectivity between the left and right ATL during semantic processing. Furthermore, the ATL GM changes were associated with the functional connectivity changes in the ATL-connectivity during semantic processing. These structural alterations are mirrored by functional changes in cortical excitability attributed to the GM changes and demonstrate the rapid dynamics of cortical plasticity. Our findings support fast adjusting neuronal systems, such as postsynaptic morphology changes and neuronal turnover. Our results suggest that TBS is able to produce powerful changes in regional synaptic activity in human adult brain

Dorsolateral Prefrontal Cortex: A Possible Target for Modulating Dyskinesias in Parkinson's Disease by Repetitive Transcranial Magnetic Stimulation

We studied whether five sessions of 10 Hz repetitive transcranial magnetic stimulation (rTMS treatment) applied over the dorsolateral prefrontal cortex (DLPFC) or the primary motor cortex (MC) in advanced Parkinson's disease (PD) patients would have any effect on L-dopa-induced dyskinesias and cortical excitability. We aimed at a randomised, controlled study. Single-pulse transcranial magnetic stimulation (TMS), paired-pulse transcranial magnetic stimulation, and the Unified Parkinson's Disease Rating Scale (UPDRS parts III and IV) were performed prior to, immediately after, and one week after an appropriate rTMS treatment. Stimulation of the left DLPFC induced a significant motor cortex depression and a trend towards the improvement of L-dopa-induced dyskinesias

Ergastava transkraniaalse magnetstimulatsiooni mõju petukäitumisele

The present study investigated the effects of excitation of the dorsolateral prefrontal cortex (DLPFC) with repetitive transcranial magnetic stimulation (rTMS) on deceptive behaviour. The event-related potential (ERP) component P300 is well known as a neural marker of deception. P300 amplitude was examined in response to critical, familiar, and neutral stimuli in a task similar to the concealed information test. The electroencephalography (EEG) of 13 volunteers was recorded combined with rTMS. We did not find a difference in response to rTMS between right and left DLPFC as initially expected. However, TMS elicited a higher mean P300 amplitude to the critical stimulus compared to sham condition. Therefore, noninvasive prefrontal cortex excitation by rTMS can be used to increase the sensitivity of P300 to critical items in an analogue of the concealed information test

Mechanisms and therapeutic applications of electromagnetic therapy in Parkinson's disease

© 2015 Vadalà et al. Electromagnetic therapy is a non-invasive and safe approach for the management of several pathological conditions including neurodegenerative diseases. Parkinson's disease is a neurodegenerative pathology caused by abnormal degeneration of dopaminergic neurons in the ventral tegmental area and substantia nigra pars compacta in the midbrain resulting in damage to the basal ganglia. Electromagnetic therapy has been extensively used in the clinical setting in the form of transcranial magnetic stimulation, repetitive transcranial magnetic stimulation, high-frequency transcranial magnetic stimulation and pulsed electromagnetic field therapy which can also be used in the domestic setting. In this review, we discuss the mechanisms and therapeutic applications of electromagnetic therapy to alleviate motor and non-motor deficits that characterize Parkinson's disease

Voluntary activation of human knee extensors measured using transcranial magnetic stimulation

The aim of this study was to determine the applicability and reliability of a transcranial magnetic stimulation twitch interpolation technique for measuring voluntary activation of a lower limb muscle group. Cortical voluntary activation of the knee extensors was determined in nine healthy men on two separate visits by measuring superimposed twitch torques evoked by transcranial magnetic stimulation during isometric knee extensions of varying intensity. Superimposed twitch amplitude decreased linearly with increasing voluntary torque between 50 and 100% of mean maximal torque, allowing estimation of resting twitch amplitude and subsequent calculation of voluntary activation. There were no systematic differences for maximal voluntary activation within day (mean ± S.D. 90.9 ± 6.2 versus 90.7 ± 5.9%; P = 0.98) or between days (90.8 ± 6.0 versus 91.2 ± 5.7%; P = 0.92). Systematic bias and random error components of the 95% limits of agreement were 0.23 and 9.3% within day versus −0.38 and 7.5% between days. Voluntary activation was also determined immediately after a 2 min maximal voluntary isometric contraction; in four of these subjects, voluntary activation was determined 30 min after the sustained contraction. Immediately after the sustained isometric contraction, maximal voluntary activation was reduced from 91.2 ± 5.7 to 74.2 ± 12.0% (P < 0.001), indicating supraspinal fatigue. After 30 min, voluntary activation had recovered to 85.4 ± 8.8% (P = 0.39 versus baseline). These results demonstrate that transcranial magnetic stimulation enables reliable measurement of maximal voluntary activation and assessment of supraspinal fatigue of the knee extensors