Study of the silent period following motor evoked potential by magnetic stimulation method**This work was presented, in part, at the 9th Annual Orthopaedic Research Meeting of the Japanese Orthopaedic Association, Kobe, Japan, 7-8 October 1994, and at the Xth International Congress of EMG and Clinical Neurophysiology, Kyoto, Japan, 15-19 October 1995.

1996 ◽  
Vol 1 (5) ◽  
pp. 301-306
Author(s):  
Naohito Suyama ◽  
Hiroyuki Shindo ◽  
Tadashi Iizuka
Keyword(s):  
Magnetic Stimulation ◽  
Evoked Potential ◽  
Clinical Neurophysiology ◽  
Japanese Orthopaedic Association ◽  
Motor Evoked Potential ◽  
Silent Period ◽  
International Congress ◽  
Orthopaedic Research ◽  
Stimulation Method ◽  
Research Meeting

The effect of acetaminophen ingestion on cortico-spinal excitability

2013 ◽  
Vol 91 (2) ◽  
pp. 187-189 ◽  
Author(s):  
Alexis R. Mauger ◽  
James G. Hopker
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Evoked Potential ◽  
Motor Evoked Potential ◽  
Silent Period ◽  
Sodium Currents ◽  
Cortical Silent Period ◽  
Voltage Gated ◽  
Spinal Excitability

Acetaminophen (ACT) facilitates the inhibition of voltage-gated calcium and sodium currents, which may effect cortico-spinal excitability. Twelve subjects ingested acetaminophen or a placebo and underwent transcranial magnetic stimulation to assess the motor evoked potential (MEP), and cortical silent period (CSP). ACT significantly increased MEP response (P > 0.05) but had no effect on CSP (P > 0.05). This indicates that ACT increases MEP and should be controlled for in studies where these measures are of interest.

scholarly journals Modulation of the Corticomotor Excitability by Repetitive Peripheral Magnetic Stimulation on the Median Nerve in Healthy Subjects

2021 ◽  
Vol 15 ◽  
Author(s):  
Yanbing Jia ◽  
Xiaoyan Liu ◽  
Jing Wei ◽  
Duo Li ◽  
Chun Wang ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Healthy Subjects ◽  
Magnetic Stimulation ◽  
Evoked Potential ◽  
Sham Group ◽  
Motor Evoked Potential ◽  
Dominant Hand ◽  
Corticomotor Excitability ◽  
Hand Dexterity ◽  
Stimulation Group

Objective: We aimed to examine the effects of repetitive peripheral nerve magnetic stimulation (rPNMS) on the excitability of the contralateral motor cortex and motor function of the upper limb in healthy subjects.Methods: Forty-six healthy subjects were randomly assigned to either a repetitive peripheral nerve magnetic stimulation group (n = 23) or a sham group (n = 23). The repetitive peripheral nerve magnetic stimulation group received stimulation using magnetic pulses at 20 Hz, which were applied on the median nerve of the non-dominant hand, whereas the sham group underwent the same protocol without the stimulation output. The primary outcome was contralateral transcranial magnetic stimulation (TMS)-induced corticomotor excitability for the abductor pollicis brevis of the stimulated hand in terms of resting motor threshold (rMT), the slope of recruitment curve, and peak amplitude of motor evoked potential (MEP), which were measured at baseline and immediately after each session. The secondary outcomes were motor hand function including dexterity and grip strength of the non-dominant hand assessed at baseline, immediately after stimulation, and 24 h post-stimulation.Results: Compared with the sham stimulation, repetitive peripheral nerve magnetic stimulation increased the peak motor evoked potential amplitude immediately after the intervention. The repetitive peripheral nerve magnetic stimulation also increased the slope of the recruitment curve immediately after intervention and enhanced hand dexterity after 24 h. However, the between-group difference for the changes was not significant. The significant changes in hand dexterity and peak amplitude of motor evoked potential after repetitive peripheral nerve magnetic stimulation were associated with their baseline value.Conclusions: Repetitive peripheral nerve magnetic stimulation may modulate the corticomotor excitability together with a possible lasting improvement in hand dexterity, indicating that it might be helpful for clinical rehabilitation.

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.

A new concept in the electrophysiological evaluation of syringomyelia

2008 ◽  
Vol 8 (6) ◽  
pp. 517-523 ◽  
Author(s):  
Florian Roser ◽  
Florian H. Ebner ◽  
Marina Liebsch ◽  
Klaus Dietz ◽  
Marcos Tatagiba
Keyword(s):  
Evoked Potential ◽  
Clinical Symptoms ◽  
Early Stage ◽  
Motor Evoked Potential ◽  
Silent Period ◽  
Preoperative Assessment ◽  
Central Canal ◽  
Spinothalamic Tract ◽  
Specific Symptom ◽  
Electrophysiological Measurements

Object The current neurophysiological assessment of syringomyelia is inadequate. Early-stage syringomyelia is anatomically predisposed to affect decussating spinothalamic fibers that convey pain and sensation primarily. Silent periods have been proven to be a sensitive tool for detecting alterations in this pathway. Methods Thirty-seven patients with syringomyelia were included in this prospective study. Routine electrophysiological measurements were applied including somatosensory evoked potential (SSEP) and motor evoked potential (MEP) recordings for all extremities. The silent periods were recorded from the pollicis brevis muscle, and electrical stimuli were applied to the ipsilateral digiti II. To establish baseline values, the authors had 28 healthy controls undergo monitoring. Sensitivity and specificity values were statistically evaluated according to the main clinical symptoms (paresis, dissociative syndrome, and pain). Results All control individuals had normal silent periods in voluntarily activated muscle. In syringomyelia patients, the affected limb showed pathological silent periods with all symptoms (sensitivity 30–50%). Pain was the most specific symptom (90%), despite SSEP and MEP values that were within the normal range. Conclusions Silent period testing is a sensitive neurophysiological technique and an invaluable tool for preoperative assessment of syringomyelia. Silent periods are associated with early dysfunction of thin myelinated spinothalamic tract fibers, even when routine electrophysiological measurements still reveal normal values. Conduction abnormalities that selectively abolish the silent periods can distinguish between hydromyelia (a physiologically dilated central canal) and space-occupying syringomyelia.

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