Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control最新文献

{"title":"Postural reflexes in patients with HIV-1 infection","authors":"Dennis J Beckley ,&nbsp;Bastiaan R Bloem ,&nbsp;Eileen M Martin ,&nbsp;Victoria P Panzer ,&nbsp;Michael P Remler","doi":"10.1016/S0924-980X(98)00040-X","DOIUrl":"10.1016/S0924-980X(98)00040-X","url":null,"abstract":"<div><p><strong>Objective</strong>: We studied whether medium latency (ML) and long latency (LL) postural reflexes, which are abnormal in a number of neurological conditions including basal ganglia disorders, provide an early marker of CNS involvement in HIV-positive patients.</p><p><strong>Methods</strong>: Leg reflexes were elicited in 9 neurologically normal HIV-positive patients and 10 healthy controls who were standing upright, using toe-up forceplate rotations of varying amplitude (4° and 10°) and predictability (serial and random).</p><p><strong>Results</strong>: For predictable amplitude perturbations, posturally destabilizing ML and stabilizing LL responses in HIV-seropositives did not differ from controls. However, for unpredictable amplitude perturbations, HIV-positive patients inappropriately manifested a mid-size default LL response, in contrast to healthy subjects who showed a maximum size default response.</p><p><strong>Conclusions</strong>: These results suggest that impaired modulation of LL reflex processing occurs in early stages of HIV infection, prior to the onset of clinical postural instability, and this dysregulation may be influenced by cognitive factors.</p></div>","PeriodicalId":100400,"journal":{"name":"Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control","volume":"109 5","pages":"Pages 402-408"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0924-980X(98)00040-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20759346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The physiological origin of the slow afterwave in muscle action potentials1","authors":"Zoia C Lateva,&nbsp;Kevin C McGill","doi":"10.1016/S0924-980X(98)00048-4","DOIUrl":"https://doi.org/10.1016/S0924-980X(98)00048-4","url":null,"abstract":"<div><p><strong>Objective</strong><span>: Both intramuscularly-recorded motor unit action potentials (MUAPs) and surface recorded MUAPs and compound muscle action potentials<span> (CMAPs) have slow afterwaves which can contribute as much as half their measured duration. This study tested the hypothesis that the slow afterwave has its physiological origin in the negative afterpotential of the muscle fiber intracellular action potential (IAP).</span></span></p><p><strong>Methods</strong><span>: We investigated the slow afterwave in MUAPs and CMAPs from brachial biceps, tibialis anterior, first dorsal interosseous, thenar and hypothenar muscles in 15 normal subjects, and using computer simulations.</span></p><p><strong>Results</strong>: The slow afterwaves did not match the time constant of the amplifier's high-pass filter, and so were not filtering artifacts. They lasted long after propagation had terminated at the muscle/tendon junction, and so were not due to the temporal or spatial dispersion of propagating single-fiber potentials. Their amplitude and polarity varied with the recording site as predicted by computer simulations that modeled the IAP as having a negative afterpotential. They also changed with double-pulse stimulation and decreasing temperature in ways consistent with the results of intracellular studies of the IAP negative afterpotential.</p><p><strong>Conclusions</strong>: The presented results support our hypothesis that the slow afterwave is a manifestation of the IAP negative afterpotential.</p></div>","PeriodicalId":100400,"journal":{"name":"Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control","volume":"109 5","pages":"Pages 462-469"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0924-980X(98)00048-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91764552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dependence of the transcranially induced silent period on the `instruction set' and the individual reaction time","authors":"J Mathis,&nbsp;D de Quervain,&nbsp;C.W Hess","doi":"10.1016/S0924-980X(98)00042-3","DOIUrl":"10.1016/S0924-980X(98)00042-3","url":null,"abstract":"<div><p><strong>Objectives and methods</strong><span>: We looked for influences of the experimental condition on the silent period (SP) from transcranial motor cortex stimulation and analyzed how the instruction given to the subject, as well as the individual reaction time, might affect the duration of the SP in the biceps brachii muscle.</span><strong>Results</strong>: The duration of the SP was found to critically depend on the subject's voluntary reaction of the target muscle immediately after the stimulus. With low stimulus intensity and low background force, the duration of the silent period was significantly <em>longer</em> in 10 of 13 subjects (<em>P</em>=0.002) when they were instructed to relax quickly after the stimulus rather than to maintain the force at constant level. A significant <em>shortening</em> of the SP (<em>P</em>=0.02) was observed when the subjects were instructed to perform a rapid contraction of the target muscle in reaction to the cortical stimulus. With low stimulus intensity and high background force, the same influence of the instruction set was found in 6 of 13 subjects. When the subjects were left without precise instruction, the SP duration was unpredictable. In 10 subjects, the SP corresponded to that obtained with the instruction to maintain the force at constant level. However, in 3 subjects it was prolonged to the value observed in the `relax' instruction. With greater stimulus intensities, the effect of the instruction set on the SP duration was generally smaller. A significant prolongation was nevertheless found at low background forces with rapid relaxation (<em>P</em>&lt;0.001), and a significant shortening was found at high background forces with rapid contraction (<em>P</em>&lt;0.001) after the stimulus. The SP duration observed with 20% of maximal voluntary contraction (MVC) significantly correlated with the individual reaction time. No such correlation was found for the SP obtained with 80% MVC. The SP was slightly longer at 20% MVC, as compared to 80% MVC within each instruction group. This effect was significant (<em>P</em>&lt;0.05) at low stimulus intensities. <strong>Conclusions</strong>: Therefore, when assessing the SP duration for diagnostic purposes, not only the stimulus intensity but also the background force and the voluntary reaction must be standardized. Furthermore, great stimulus intensities and high background forces should be used to minimise the effects of instruction set and individual reaction time.</p></div>","PeriodicalId":100400,"journal":{"name":"Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control","volume":"109 5","pages":"Pages 426-435"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0924-980X(98)00042-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20761069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-latency response to transcranial magnetic stimulation in patients with hemifacial spasm","authors":"Atsuhiro Kojima ,&nbsp;Takayuki Ohira ,&nbsp;Moriichiro Takase ,&nbsp;Takeshi Kawase","doi":"10.1016/S0924-980X(98)00019-8","DOIUrl":"10.1016/S0924-980X(98)00019-8","url":null,"abstract":"<div><p><em>Objective</em><span><span>: We studied the long-latency response of the orbicularis oris muscle elicited with transcranial magnetic stimulation in patients with </span>hemifacial spasm (HFS) and evaluated the excitability of the facial nucleus. </span><em>Methods</em><span>: We compared the thresholds on both sides in 8 normal volunteers and 7 patients with hemifacial spasm. The thresholds were determined as the lowest intensity required to produce motor evoked potentials with an amplitude of at least 50 </span><em>μ</em><span>V in the orbicularis oris muscle. Average values were given as means±standard deviation. Wilcoxon's rank sum test was used for comparisons between the sides of normal subjects and of patients with HFS with respect to the threshold stimulus. </span><em>Results</em>: There was no significant difference between the thresholds on the two sides of the normal subjects (mean 1.88±5.30%, <em>P</em>&gt;0.05). In patients with HFS, there was a significant difference between the thresholds on the spasm side and the normal side (mean 20.7±13.0%, <em>P</em><span>&lt;0 05) In one patient studied after MVD, the difference between both sides disappeared. </span><em>Conclusion</em>: The difference between the thresholds in patients with HFS and the normalization in threshold after MVD suggested that the mechanism of HFS was hyperexcitability of the facial nucleus.</p></div>","PeriodicalId":100400,"journal":{"name":"Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control","volume":"109 4","pages":"Pages 285-289"},"PeriodicalIF":0.0,"publicationDate":"1998-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0924-980X(98)00019-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20665363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Latency of changes in spinal motoneuron excitability evoked by transcranial magnetic brain stimulation in spinal cord injured individuals","authors":"Natalia Alexeeva,&nbsp;James G Broton,&nbsp;Blair Calancie","doi":"10.1016/S0924-980X(98)00021-6","DOIUrl":"10.1016/S0924-980X(98)00021-6","url":null,"abstract":"<div><p><strong>Objectives</strong>: To examine the basis for delay in the excitatory effects of transcranial magnetic stimulation (TMS) of motor cortex on motoneuron pools of muscles left partially-paralyzed by traumatic spinal cord injury (SCI).</p><p><strong>Methods</strong>: The effect of subthreshold transcranial magnetic stimulation (TMS) on just-suprathreshold H-reflex amplitude was examined in subjects (<em>n</em>=10) with incomplete cervical SCI, and in able-bodied (AB) subjects (<em>n</em>=20) for comparison. EMG activity was recorded from the soleus and the abductor hallucis muscles, and H-reflex was elicited by stimulation of the tibial nerve behind the knee. Comparison of the peak-to-peak amplitude of the TMS-conditioned H-reflex to that of the H-reflex alone (i.e. unconditioned H-reflex) was made for different conditioning-test intervals with multivariate analysis of variance and (when called for) <em>t</em> testing.</p><p><strong>Results</strong>: The absolute latencies of motor responses to suprathreshold TMS delivered during a weak voluntary contraction of the soleus and abductor hallucis were significantly prolonged in the SCI group relative to AB subjects. For the TMS-conditioned H-reflex, the time-course effect of TMS on the H-reflex amplitude in different AB subjects included an early effect (typically facilitation, but occasionally inhibition) seen between −5 and 0 ms, followed by a later period (i.e. &gt;5 ms) of H-reflex facilitation. In contrast, the earliest indication of a TMS effect on H-reflex excitability in SCI subjects was between 5 and 10 ms after TMS. This difference between SCI and AB subjects of approximately 10 ms was similar to the prolongation of TMS-evoked response latencies in the soleus and the abductor hallucis muscles of the SCI subjects.</p><p><strong>Conclusions</strong>: The results suggest that motor conduction slowing after traumatic SCI most likely occurs across the population of the descending tract axons mediating the TMS-evoked motor responses.</p></div>","PeriodicalId":100400,"journal":{"name":"Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control","volume":"109 4","pages":"Pages 297-303"},"PeriodicalIF":0.0,"publicationDate":"1998-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0924-980X(98)00021-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20665365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reproducibility of electromyographic recordings of submaximal concentric and eccentric muscle contractions in humans","authors":"S.D.G Finucane,&nbsp;T Rafeei,&nbsp;J Kues,&nbsp;R.L Lamb,&nbsp;T.P Mayhew","doi":"10.1016/S0924-980X(98)00020-4","DOIUrl":"10.1016/S0924-980X(98)00020-4","url":null,"abstract":"<div><p><strong>Objectives</strong><span>: to determine the intratester and intertester reliability of measures of electromyographic activity (EMG) of submaximal concentric and eccentric contractions and to compare the reliability of normalized and non-normalized measures of EMG. There were 10 subjects, of 22–33 years old.</span></p><p><strong>Methods</strong><span>: Subjects performed submaximal concentric and eccentric contractions at 60°/s, and maximal isometric contractions<span> (MIC) of their knee extensors. The target power of the submaximal contractions was 90%±10% of the subject's maximal concentric power. EMG was recorded via bipolar surface electrodes from 3 of the quadriceps femoris muscles. The rmsEMG for submaximal contractions that were within the target power range were determined. The rmsEMG for the submaximal contractions were normalized to the rmsEMG of the maximal isometric contractions. Intraclass correlation coefficients (ICC version 1.1) were calculated to determine intratester and intertester reliability.</span></span></p><p><strong>Results</strong>: For non-normalized rmsEMG, ICC values for intratester reliability ranged from 0.62 to 0.91 for concentric and from 0.84 to 0.97 for eccentric contractions. ICC values for intertester reliability ranged from 0.66 to 0.96 for concentric and 0.78 to 0.90 for eccentric contractions.</p><p><strong>Conclusions</strong>: Non-normalized rmsEMG of submaximal concentric and eccentric isokinetic contractions were found to be reliable. Normalization did not lead to consistently improved reliability.</p></div>","PeriodicalId":100400,"journal":{"name":"Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control","volume":"109 4","pages":"Pages 290-296"},"PeriodicalIF":0.0,"publicationDate":"1998-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0924-980X(98)00020-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20665364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time dependent selective recurrent discharge of motor units in F-response1","authors":"Sunil Pradhan","doi":"10.1016/S0924-980X(98)00028-9","DOIUrl":"10.1016/S0924-980X(98)00028-9","url":null,"abstract":"<div><p><span>The interaction among the recurrent discharge of motor units is studied in surface recorded composite F-response. In the first experiment, 200 serially elicited polyphasic F-responses from foot muscles of patients with different lower motor neurone (LMN) disorders were rearranged to understand the behaviour of individual negative and positive peaks. These peaks were considered on the basis of simultaneous recording with a single fibre EMG needle, to be the partial expression of either a single motor unit potential (MUP) or more than one MUP generated simultaneously. In another experiment, two serially averaged F-responses (50 each) were superimposed over each other to look for their similarities at 15 min intervals 6 times. Result analysis indicated interaction of MUPs by in-phase summation and out-of-phase subtraction. Less affected MUPs recurred as negative or positive peaks in morphologically different F-responses. Certain peaks were observed more frequently than the others. Two serially averaged F-responses were nearly identical on superimposition over each other but their morphologies differed at different time intervals. The study suggests more frequent generation of F-response in a specific group of alpha </span>motoneurones at one point of time, which is replaced by another group at another point of time. The characteristic variation in F parameters is, however, mainly due to the interaction of these frequently generated F-response MUPs with other sporadically generated ones. This interaction can be appreciated on visual screening of F-responses in patients with lower motor neurone disorders, perhaps because of a reduction in the number of participating MUPs.</p></div>","PeriodicalId":100400,"journal":{"name":"Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control","volume":"109 4","pages":"Pages 341-349"},"PeriodicalIF":0.0,"publicationDate":"1998-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0924-980X(98)00028-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20664662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anticipatory postural adjustments in conditions of postural instability","authors":"Alexander S Aruin ,&nbsp;William R Forrest ,&nbsp;Mark L Latash","doi":"10.1016/S0924-980X(98)00029-0","DOIUrl":"10.1016/S0924-980X(98)00029-0","url":null,"abstract":"<div><p><strong>Objectives</strong>: The purpose of this study was to investigate anticipatory postural adjustments (APAs) in standing subjects who performed a standard motor action triggering a standard postural perturbation (releasing a 2.2 kg load from extended arms) in conditions of different stability requirements.</p><p><strong>Methods</strong><span>: The degree of stability was varied either by balancing on special boards with long and narrow support beams or by instructions to the subjects. In the first series of experiments 13 subjects stood on the board facing either perpendicular to the beam (instability in a sagittal plane) or along the beam (instability in frontal plane); different widths of the beam were used to vary the degree of instability. During the second series of experiments (6 subjects) inclined and one-legged postures were used to induce instability in sagittal and frontal planes respectively. EMG activity of rectus abdominis, erector spinae, rectus femoris, biceps femoris, tibialis anterior, and soleus muscles were recorded. Statistical methods included repeated measures analysis of variance (ANOVA) with direction of instability and level of instability being major factors, descriptive statistics, and post hoc Student's </span><em>t</em> tests.</p><p><strong>Results</strong>: The integral measure of changes in the background electromyographic activity of postural muscles during APAs depended on two factors related to the postural task: (1) standing on a platform with a narrow support area led to an attenuation of the APAs; and (2) these effects were stronger when instability was in a sagittal rather than in the frontal plane. The anticipatory component in the displacement of the center of pressure did not show a clear attenuation that would depend on the direction of instability.</p><p><strong>Conclusions</strong>: We suggest a hypothesis that, in conditions of high stability demands, the central nervous system may suppress APAs as a protection against their possible destabilizing effects. These effects are more pronounced when the direction of an expected perturbation is in the plane of instability.</p></div>","PeriodicalId":100400,"journal":{"name":"Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control","volume":"109 4","pages":"Pages 350-359"},"PeriodicalIF":0.0,"publicationDate":"1998-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0924-980X(98)00029-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20664663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Responses of masseter muscles to transcranial magnetic stimulation in patients with amyotrophic lateral sclerosis","authors":"C Trompetto,&nbsp;C Caponnetto,&nbsp;A Buccolieri,&nbsp;R Marchese,&nbsp;G Abbruzzese","doi":"10.1016/S0924-980X(98)00025-3","DOIUrl":"10.1016/S0924-980X(98)00025-3","url":null,"abstract":"<div><p><span><span>We recorded motor responses evoked by transcranial magnetic stimulation (TMS) in the </span>masseter muscles<span><span> of 30 patients with amyotrophic lateral sclerosis (ALS), 10 patients with cervical spondylotic </span>myelopathy (CSM) and 22 age-matched normal controls. Responses to direct activation of the trigeminal motor root (R-MEPs) were normal both in ALS and CSM patients. Responses to activation of cortico-bulbar descending fibers (C-MEPs) were absent or delayed in 19 ALS patients (63.3%). Abnormalities of masseter C-MEPs were more frequent than abnormalities of limb MEPs and could be observed both in patients with (77.8%) and without (41.7%) clinical </span></span>bulbar signs<span>. Masseter C-MEPs were normal in all CSM patients. Recording masseter responses to TMS can reveal the frequent impairment of cortico-bulbar projections in ALS and can be useful in the differential diagnosis<span> of spinal cord compression disorders mimicking ALS because of combination of upper and lower motor neuron signs.</span></span></p></div>","PeriodicalId":100400,"journal":{"name":"Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control","volume":"109 4","pages":"Pages 309-314"},"PeriodicalIF":0.0,"publicationDate":"1998-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0924-980X(98)00025-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20665367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pharmacological control of facilitatory I-wave interaction in the human motor cortex. A paired transcranial magnetic stimulation study","authors":"Ulf Ziemann,&nbsp;Frithjof Tergau,&nbsp;Stephan Wischer,&nbsp;Jörg Hildebrandt,&nbsp;Walter Paulus","doi":"10.1016/S0924-980X(98)00023-X","DOIUrl":"10.1016/S0924-980X(98)00023-X","url":null,"abstract":"<div><p><span><span>A novel paired transcranial magnetic stimulation (TMS) paradigm with a suprathreshold first and a subthreshold second stimulus was used in healthy volunteers to investigate the acute effects of a single oral dose of various CNS-active drugs on short-interval motor evoked potential (MEP) facilitation. MEPs were recorded from the relaxed abductor digiti muscle. Three peaks of MEP facilitation were consistently observed at interstimulus intervals of 1.1–1.5 ms, 2.3–2.7 ms, and 3.9–4.5 ms. The size of these MEP peaks was transiently suppressed by drugs which enhance gamma-aminobutyric acid (GABA) function in the neocortex (lorazepam, </span>vigabatrin, </span>phenobarbital<span><span>, ethanol), while the GABA-B receptor agonist baclofen<span>, anti-glutamate drugs (gabapentin, memantine), and sodium channel blockers (carbamazepine, lamotrigine) had no effect. The interstimulus intervals effective for the production of the MEP peaks remained unaffected by all drugs. The MEP peaks are thought to be due to a facilitatory interaction of I-(indirect) waves in the motor cortex. Therefore, the present results indicate that the production of I-waves is primarily controlled by GABA related neuronal circuits. The potential relevance of this non-invasive paired TMS protocol for the investigation of I-waves in patients with </span></span>neurological disease will be discussed.</span></p></div>","PeriodicalId":100400,"journal":{"name":"Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control","volume":"109 4","pages":"Pages 321-330"},"PeriodicalIF":0.0,"publicationDate":"1998-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0924-980X(98)00023-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20664660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}