Recurrent CSPs after Transcranial Magnetic Stimulation of Motor Cortex in Restless Legs Syndrome

Aims.The aim of this study was to investigate the motor control and central silent period (CSP) in restless legs syndrome (RLS).Methods.Transcranial magnetic stimulation was focused on the dominant and nondominant hemispheric areas of motor cortex in six subjects with RLS and six controls. The responses were recorded on the contralateral abductor digiti minimi (ADM) and tibialis anterior (TA) muscles with intramuscular needle electrodes.Results.No significant differences were found in the motor conduction or central motor conduction time, in the latency, or in the duration of the CSPs between or within the groups, but multiple CSPs were observed in both groups. The number of the CSPs was significantly higher in both ADMs and in the dominant TA (P≤0.01) in the RLS group compared to the controls.Conclusion.Descending motor pathways functioned correctly in both groups. The occurrence of the recurrent CSPs predominantly in the RLS group could be a sign of a change of function in the inhibitory control system. Further research is needed to clarify the role of the intramuscular recording technique and especially the role of the subcortical generators in the feedback regulation of the central nervous system in RLS.

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Interhemispheric Connectivity in Idiopathic Cervical Dystonia and Spinocerebellar Ataxias: A Transcranial Magnetic Stimulation Study

Clinical EEG and Neuroscience ◽

10.1177/1550059420957487 ◽

2020 ◽

pp. 155005942095748 ◽

Cited By ~ 1

Author(s):

Tommaso Bocci ◽

Davide Baloscio ◽

Roberta Ferrucci ◽

Lucia Briscese ◽

Alberto Priori ◽

...

Keyword(s):

Transcranial Magnetic Stimulation ◽

Cervical Dystonia ◽

Magnetic Stimulation ◽

Silent Period ◽

Cortical Inhibition ◽

Common Disease ◽

Conduction Time ◽

Mutational Load ◽

Spinocerebellar Ataxias ◽

Interhemispheric Communication

Background and Rationale Hyperkinetic movement disorders represent a heterogeneous group of diseases, different from a genetic and clinical perspective. In the past, neurophysiological approaches provided different, sometimes contradictory findings, pointing to an impaired cortical inhibition as a common electrophysiological marker. Our aim was to evaluate changes in interhemispheric communication in patients with idiopathic cervical dystonia (ICD) and spinocerebellar ataxias (SCAs). Materials and Methods Eleven patients with ICD, 7 with genetically confirmed SCA2 or SCA3, and 10 healthy volunteers were enrolled. The onset latency and duration of the ipsilateral silent period (iSPOL and iSPD, respectively), as well as the so-called transcallosal conduction time (TCT), were then recorded from the abductor pollicis brevis of the right side using an 8-shaped focal coil with wing diameters of 70 mm; all these parameters were evaluated and compared among groups. In SCAs, changes in neurophysiological measures were also correlated to the mutational load. Results iSPD was significantly shorter in patients with SCA2 and SCA3, when compared both to control and ICD ( P < .0001); iSPOL and TCT were prolonged in SCAs patients ( P < .001). Changes in iSPD, iSPOL, and TCT in SCAs are significantly correlated with the mutational load ( P = .01, P = .02, and P = .002, respectively). Discussion This is the first study to assess changes in interhemispheric communication in patients with SCAs and ICD, using a transcranial magnetic stimulation protocol. Together with previous data in Huntington’s disease, we suggest that these changes may underlie, at least in part, a common disease mechanism of polyglutamine disorders.

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Transcranial Magnetic Stimulation as a Tool to Study the Role of the Motor Cortex in Human Muscle Function

Neuromuscular Aspects of Sport Performance ◽

10.1002/9781444324822.ch8 ◽

2010 ◽

pp. 115-134 ◽

Cited By ~ 2

Author(s):

Janne Avela ◽

Markus Gruber

Keyword(s):

Transcranial Magnetic Stimulation ◽

Motor Cortex ◽

Muscle Function ◽

Magnetic Stimulation ◽

Human Muscle

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Transcranial magnetic stimulation

10.1093/med/9780199688395.003.0014 ◽

2016 ◽

Cited By ~ 1

Author(s):

Kerry R. Mills

Keyword(s):

Transcranial Magnetic Stimulation ◽

Motor Neurons ◽

Magnetic Stimulation ◽

Motor Evoked Potential ◽

Silent Period ◽

Demyelinating Diseases ◽

Conduction Time ◽

Spinal Motor Neurons ◽

Basic Physics ◽

Clinical Measures

Transcranial magnetic stimulation (TMS) has been exploited to advance knowledge of corticospinal physiology and, in a number of conditions, to aid diagnosis and quantify corticospinal abnormalities. The basic physics of magnetic stimulation is described along with the effects of stimulating coils with different dimensions and shape. The effects of single TMS pulses over motor cortex to cause a descending volley of D and I waves, and their effects on spinal motor neurons resulting in a motor evoked potential (MEP) are described. Guidelines for the safe use of TMS are given. Methods to estimate useful clinical measures of corticospinal function, such as threshold, MEP amplitude, central motor conduction time, silent period and input:output relation are given, as is the means to quantify corticospinal conduction using the triple stimulation technique. The clinical utility of TMS in neurodegenerations, central demyelinating diseases, stroke, spinal cord disease, movement disorders, and functional disorders is discussed.

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Disrupted Central Inhibition after Transcranial Magnetic Stimulation of Motor Cortex in Schizophrenia with Long-Term Antipsychotic Treatment

ISRN Psychiatry ◽

10.1155/2013/876171 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Aulikki Ahlgrén-Rimpiläinen ◽

Hannu Lauerma ◽

Seppo Kähkönen ◽

Ilpo Rimpiläinen

Keyword(s):

Transcranial Magnetic Stimulation ◽

Motor Cortex ◽

Magnetic Stimulation ◽

Motor Evoked Potentials ◽

Silent Period ◽

Single Pulse ◽

Contralateral Side ◽

Antipsychotic Treatment ◽

Stimulation Of

Aims. Schizophrenia is a neuropsychiatric disorder associated with mental and motor disturbances. We aimed to investigate motor control, especially central silent period (CSP) in subjects with schizophrenia (n=11) on long-term antipsychotic treatment compared to healthy controls (n=9). Methods. Latency and duration of motor evoked potentials (MEPs) and CSPs were measured with the help of single pulse transcranial magnetic stimulation (TMS) and intramuscular electrodes. After stimulation of the dominant and nondominant motor cortex of abductor digiti minimi (ADM) and tibialis anterior (TA) muscle areas, respective responses were measured on the contralateral side. Results. MEPs did not differ significantly between the groups. Multiple CSPs were found predominantly in subjects with schizophrenia, which showed a higher number of CSPs in the dominant ADM and the longest summarized duration of CSPs in the nondominant ADM (P<0.05) compared to controls. Conclusions. There were multiple CSPs predominantly in the upper extremities and in the dominant body side in subjects with schizophrenia. Behind multiple CSPs may lie an impaired regulation of excitatory or inhibitory neurotransmitter systems in central motor pathways. Further research is needed to clarify the role of the intramuscular recording methods and the effect of antipsychotics on the results.

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Interictal inhibitory mechanisms in patients with cryptogenic motor cortex epilepsy: a study of the silent period following transcranial magnetic stimulation

Electroencephalography and Clinical Neurophysiology ◽

10.1016/s0013-4694(98)00035-2 ◽

1998 ◽

Vol 107 (1) ◽

pp. 1-7 ◽

Cited By ~ 37

Author(s):

M Cincotta ◽

A Borgheresi ◽

S Lori ◽

M Fabbri ◽

G Zaccara

Keyword(s):

Transcranial Magnetic Stimulation ◽

Motor Cortex ◽

Magnetic Stimulation ◽

Silent Period ◽

Inhibitory Mechanisms

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Contribution of transcranial magnetic stimulation in restless legs syndrome: pathophysiological insights and therapeutical approaches

Sleep Medicine ◽

10.1016/j.sleep.2019.12.009 ◽

2020 ◽

Vol 71 ◽

pp. 124-134 ◽

Cited By ~ 1

Author(s):

Raffaele Nardone ◽

Luca Sebastianelli ◽

Viviana Versace ◽

Francesco Brigo ◽

Stefan Golaszewski ◽

...

Keyword(s):

Transcranial Magnetic Stimulation ◽

Restless Legs Syndrome ◽

Magnetic Stimulation ◽

Restless Legs

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Late Cortical Disinhibition in Human Motor Cortex: A Triple-Pulse Transcranial Magnetic Stimulation Study

Journal of Neurophysiology ◽

10.1152/jn.00782.2009 ◽

2010 ◽

Vol 103 (1) ◽

pp. 511-518 ◽

Cited By ~ 60

Author(s):

R. F. H. Cash ◽

U. Ziemann ◽

K. Murray ◽

G. W. Thickbroom

Keyword(s):

Transcranial Magnetic Stimulation ◽

Motor Cortex ◽

Magnetic Stimulation ◽

Short Interval ◽

Motor Evoked Potential ◽

Silent Period ◽

Intracortical Inhibition ◽

Human Motor Cortex ◽

Acid Type ◽

Human Motor

In human motor cortex transcranial magnetic stimulation (TMS) has been used to identify short-interval intracortical inhibition (SICI) corresponding to γ-aminobutyric acid type A (GABAA) effects and long-interval intracortical inhibition (LICI) and the cortical silent period (SP) corresponding to postsynaptic GABAB effects. Presynaptic GABAB effects, corresponding to disinhibition, can also be identified with TMS and have been shown to be acting during LICI by measuring SICI after a suprathreshold priming stimulus (PS). The duration of disinhibition is not certain and, guided by studies in experimental preparations, we hypothesized that it may be longer-lasting than postsynaptic inhibition, leading to a period of late cortical disinhibition and consequently a net increase in corticospinal excitability. We tested this first by measuring the motor-evoked potential (MEP) to a test stimulus (TS), delivered after a PS at interpulse intervals (IPIs) ≤300 ms that encompassed the period of PS-induced LICI and its aftermath. MEP amplitude was initially decreased, but then increased at IPIs of 190–210 ms, reaching 160 ± 17% of baseline 200 ms after PS ( P < 0.05). SP duration was 181 ± 5 ms. A second experiment established that the onset of the later period of increased excitability correlated with PS intensity ( r2 = 0.99) and with the duration of the SP ( r2 = 0.99). The third and main experiment demonstrated that SICI was significantly reduced in strength at all IPIs ≤220 ms after PS. We conclude that TMS-induced LICI is associated with a period of disinhibition that is at first masked by LICI, but that outlasts LICI and gives rise to a period during which disinhibition predominates and net excitability is raised. Identification of this late period of disinhibition in human motor cortex may provide an opportunity to explore or modulate the behavior of excitatory networks at a time when inhibitory effects are restrained.

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