scholarly journals Myths and Methodologies: How loud is the story told by the transcranial magnetic stimulation‐evoked silent period?

2019 ◽  
Vol 104 (5) ◽  
pp. 635-642 ◽  
Author(s):  
Jakob Škarabot ◽  
Ricardo N. O. Mesquita ◽  
Callum G. Brownstein ◽  
Paul Ansdell
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Silent Period

scholarly journals Intracortical and Intercortical Motor Disinhibition to Transcranial Magnetic Stimulation in Newly Diagnosed Celiac Disease Patients

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1530
Author(s):  
Francesco Fisicaro ◽  
Giuseppe Lanza ◽  
Carmela Cinzia D’Agate ◽  
Raffaele Ferri ◽  
Mariagiovanna Cantone ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Rating Scale ◽  
De Novo ◽  
Motor Evoked Potentials ◽  
Silent Period ◽  
Cross Sectional ◽  
Transcallosal Inhibition ◽  
Resting Motor Threshold

Background: Celiac disease (CD) may present or be complicated by neurological and neuropsychiatric manifestations. Transcranial magnetic stimulation (TMS) probes brain excitability non-invasively, also preclinically. We previously demonstrated an intracortical motor disinhibition and hyperfacilitation in de novo CD patients, which revert back after a long-term gluten-free diet (GFD). In this cross-sectional study, we explored the interhemispheric excitability by transcallosal inhibition, which has never been investigated in CD. Methods: A total of 15 right-handed de novo, neurologically asymptomatic, CD patients and 15 age-matched healthy controls were screened for cognitive and depressive symptoms to the Montreal Cognitive Assessment (MoCA) and the 17-item Hamilton Depression Rating Scale (HDRS), respectively. TMS consisted of resting motor threshold, amplitude, latency, and duration of the motor evoked potentials, duration and latency of the contralateral silent period (cSP). Transcallosal inhibition was evaluated as duration and latency of the ipsilateral silent period (iSP). Results: MoCA and HDRS scored significantly worse in patients. The iSP and cSP were significantly shorter in duration in patients, with a positive correlation between the MoCA and iSP. Conclusions: An intracortical and interhemispheric motor disinhibition was observed in CD, suggesting the involvement of GABA-mediated cortical and callosal circuitries. Further studies correlating clinical, TMS, and neuroimaging data are needed.

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

2020 ◽  
pp. 155005942095748 ◽  
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.

Prolonged cortical silent period after transcranial magnetic stimulation in generalized epilepsy

Neurology ◽  
2001 ◽  
Vol 57 (4) ◽  
pp. 706-708 ◽  
Author(s):  
R. A.L. Macdonell ◽  
M. A. King ◽  
M. R. Newton ◽  
J. M. Curatolo ◽  
D. C. Reutens ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Silent Period ◽  
Cortical Silent Period ◽  
Generalized Epilepsy

Transcranial magnetic stimulation

2016 ◽  
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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