scholarly journals Measurement of Motor Evoked Potential in Acute Ischemic Stroke: Based on Latency, Amplitude, Central Motoric Conduction Time and Resting Motor Threshold

2016 ◽  
Vol 8 (3) ◽  
pp. 157 ◽  
Author(s):  
Tugas Ratmono ◽  
Andi Wijaya ◽  
Cahyono Kaelan ◽  
Andi Asadul Islam ◽  
Ferry Sandra
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Evoked Potential ◽  
Motor Evoked Potential ◽  
Conduction Time ◽  
Size Measurement ◽  
Motor Threshold ◽  
Dynamic Changes ◽  
Resting Motor Threshold ◽  
Function Impairment

BACKGROUND: After stroke, there are dynamic changes of motor evoked potential (MEP), including latency, amplitude, central motoric conduction time (CMCT) and resting motor threshold (RMT) in cerebral. However, latency, CMCT, amplitude and RMT have not been clearly shown in acute ischemic stroke patients with motoric function impairment based on Modified Motoric Research Council Scale (MRCs).METHODS: Patients with motoric function impairment after acute ischemic stroke were recruited, scored based on MRCs and grouped. Latency, amplitude, CMCT and RMT (% intensity) was measured using transcranial magnetic stimulation (TMS). Latency, amplitude, CMCT and RMT of subjects based on affected hemisphere (AH) and unaffected hemisphere (UH); stroke onset; and motoric severity; were analyzed and compared statistically.RESULTS: Thirty-seven subjects with complete assessments were selected. Results of MEP size measurement between AH and UH showed that latency, amplitude, CMCT and RMT of AH and UH were significantly different (p<0.05). In accordance to AH and UH results, latency, amplitude, CMCT and RMT of mild, moderate and severe groups based on motoric severity, showed that latency and CMCT were prolonged, RMT was increased, while amplitude was decreased along with severity increment. The amplitude and RMT among the groups were significantly different with p=0.034 and p=0.029, respectively.CONCLUSION: MEP size measurement including latency, amplitude, CMCT and RMT have significant different in AH and UH. In addition, amplitude and RMT were significantly different in MRCs groups, therefore the MEP size measurement could be suggested as prognostic tool.KEYWORDS: MEP, latency, amplitude, CMCT, RMT

Motor threshold, motor evoked potential, central motor conduction time

2021 ◽  
Author(s):  
Sein H. Schmidt ◽  
Stephan A. Brandt
Keyword(s):  
Magnetic Stimulation ◽  
Evoked Potential ◽  
Motor Evoked Potentials ◽  
Motor Evoked Potential ◽  
Conduction Time ◽  
Optical Navigation ◽  
Motor Threshold ◽  
Pathological Conditions ◽  
Latency Variability ◽  
First Time

In this chapter, we survey parameters influencing the assessment of the size and latency of motor evoked potentials (MEP), in normal and pathological conditions, and methods to allow for a meaningful quantification of MEP characteristics. In line with the first edition of this textbook, we extensively discuss three established mechanisms of intrinsic physiological variance and collision techniques that aim to minimize their influence. For the first time, in line with the ever wider use of optical navigation and targeting systems in brain stimulation, we discuss novel methods to capture and minimize the influence of extrinsic biophysical variance. Together, following the rules laid out in this chapter, transcranial magnetic stimulation (TMS) can account for spinal and extrinsic biophysical variance to advance investigations of the central origins of MEP size and latency variability.

scholarly journals Diaphragmatic Central Motor Conduction Changes In Chronic Obstructive Pulmonary Disease

2019 ◽  
Author(s):  
Rehab Abdelaal El-Nemr ◽  
Rania Ahmad Sweed ◽  
Hanaa Shafiek
Keyword(s):  
Pulmonary Function ◽  
Healthy Subjects ◽  
Magnetic Stimulation ◽  
Motor System ◽  
Evoked Potential ◽  
Group Versus ◽  
Motor Evoked Potential ◽  
Conduction Time ◽  
Copd Patients ◽  
Resting Motor Threshold

AbstractBackground and objectivesRespiratory muscles dysfunction has been reported in COPD. Transcranial magnetic stimulation (TMS) is easy non-invasive that has been used for assessing the respiratory corticospinal pathways particularly of diaphragm. We aimed to study the cortico-diaphragmatic motor system changes in COPD using TMS and to correlate the findings with the pulmonary function.MethodsA case control study recruited 30 stable COPD from the out-patient respiratory clinic of Main Alexandria University hospital-Egypt and 17 healthy control subjects who were subjected to spirometry. Cortical conduction of the diaphragm was performed by TMS to all participants followed by cervical magnetic stimulation of the phrenic nerve roots. Diaphragmatic resting motor threshold (DRMT), cortical motor evoked potential latency (CMEPL), CMEP amplitude (CMEPA), peripheral motor evoked potential latency (PMEPL), PMEP amplitude (PMEPA) and central motor conduction time (CMCT) were measured.Results66.7% of COPD patients had severe and very severe COPD with median age of 59 (55-63) years. There was statistically significant bilateral decrease in DRMT, CMEPA and PMEPA in COPD group versus healthy subjects and significant increase in CMEPL and PMEPL (p <0.01). Left CMCT was significantly prolonged in COPD group versus healthy subjects (p <0.0001) but not right CMCT. Further, there was significant increase in CMEPL and CMCT of left versus right diaphragm in COPD group (p= 0.003 and 0.001 respectively) that inversely correlated with FEV1% and FVC% predicted.ConclusionCentral cortico-diaphragmatic motor system is affected in COPD patients with heterogeneity of both sides that is correlated with pulmonary function.SignificanceCoticospinal pathway affection could be a factor for development of diaphragmatic dysfunction in COPD patients accordingly its evaluation could help in personalization of COPD management especially pulmonary rehabilitation programs

scholarly journals Role of Growth Factors & Neurophysiological Markers In Evaluation of Neuroplasticity Using 1Hz rTMS With Physical Therapy In Ischemic Stroke: A Double Blind, Parallel Group, Sham Controlled Randomized Trial

2021 ◽  
Author(s):  
Hina Sharma ◽  
Nand Kumar ◽  
Sreenivas Vishnubhatla ◽  
Rajeswari MR ◽  
M.V. Padma Srivast
Keyword(s):  
Ischemic Stroke ◽  
Growth Factors ◽  
Physical Therapy ◽  
Evoked Potential ◽  
Premotor Cortex ◽  
Surrogate Marker ◽  
Motor Evoked Potential ◽  
Secondary Outcome ◽  
Therapeutic Benefits ◽  
Resting Motor Threshold

Abstract Background: The therapeutic benefits of repetitive trans cranial magnetic stimulation along with physical therapy to study the neuroplasticity and neurogenesis in ischemic stroke patients has not been fully elucidated. The aim of this study is to determine the neuroplasticity using serum growth factors as a surrogate marker, using 1Hz rTMS with conventional physiotherapy in patients with sub acute ischemic stroke.Methods: In this study, participants with first ever ischemic stroke (N = 96), onset within 15 days were randomized after a run-in period of 75 ± 7 days along with standard physical therapy to receive 10 sessions of real 1Hz rTMS (N = 47) on contralesional premotor cortex or to sham stimulation (N = 49) for 2 weeks. Participants, investigators and outcome assessors were blinded. The primary efficacy outcome was change in the level of peripheral serum growth factors VEGF & BDNF at third month. The secondary outcome was measurement of neurophysiological parameters and their correlation with growth factors levels.Results: Modified intention to treat analysis showed significant up regulation in the mean level of serum VEGF & BDNF from pre to post rTMS in Real rTMS Group. Trend of decrease in Resting Motor Threshold and increase in Motor Evoked Potential in the affected hand was seen. Statistically significant negative correlation between motor evoked potential and mean VEGF (rho = -1.000, P<0.001) in the affected hand in Real rTMS Group was seen.Conclusion: Total ten sessions of 1Hz rTMS plus physical therapy on contralateral hemisphere resulted in up regulation of serum growth factors possible reflecting improved neuroplasticity. Trial funded by Indian Council of Medical Research (ICMR), India, CTRI/2016/02/006620. Retrospectively registered. Note: As this is not a regulatory trial, therefore under Indian regulatory authorities, ICMR, any trial registered before 1st April 2018 was registered as retrospective study. Ethics committee approval for this study was taken in 2012.

Motor cortex disinhibition in normal-pressure hydrocephalus

2012 ◽  
Vol 116 (2) ◽  
pp. 453-459 ◽  
Author(s):  
Andrei V. Chistyakov ◽  
Hava Hafner ◽  
Alon Sinai ◽  
Boris Kaplan ◽  
Menashe Zaaroor
Keyword(s):  
Motor Cortex ◽  
Healthy Volunteers ◽  
Normal Pressure Hydrocephalus ◽  
Close Association ◽  
Motor Evoked Potential ◽  
Normal Pressure ◽  
Corticospinal Excitability ◽  
Conduction Time ◽  
Shunt Placement ◽  
Resting Motor Threshold

Object Previous studies have shown a close association between frontal lobe dysfunction and gait disturbance in idiopathic normal-pressure hydrocephalus (iNPH). A possible mechanism linking these impairments could be a modulation of corticospinal excitability. The aim of this study was 2-fold: 1) to determine whether iNPH affects corticospinal excitability; and 2) to evaluate changes in corticospinal excitability following ventricular shunt placement in relation to clinical outcome. Methods Twenty-three patients with iNPH were examined using single- and paired-pulse transcranial magnetic stimulation of the leg motor area before and 1 month after ventricular shunt surgery. The parameters of corticospinal excitability assessed were the resting motor threshold (rMT), motor evoked potential/M-wave area ratio, central motor conduction time, intracortical facilitation, and short intracortical inhibition (SICI). The results were compared with those obtained in 8 age-matched, healthy volunteers, 19 younger healthy volunteers, and 9 age-matched patients with peripheral neuropathy. Results Significant reduction of the SICI associated with a decrease of the rMT was observed in patients with iNPH at baseline evaluation. Ventricular shunt placement resulted in significant enhancement of the SICI and increase of the rMT in patients who markedly improved, but not in those who failed to improve. Conclusions This study demonstrates that iNPH affects corticospinal excitability, causing disinhibition of the motor cortex. Recovery of corticospinal excitability following ventricular shunt placement is correlated with clinical improvement. These findings support the view that reduced control of motor output, rather than impairment of central motor conduction, is responsible for gait disturbances in patients with iNPH.

Low-Threshold Monopolar Motor Mapping for Resection of Primary Motor Cortex Tumors

2012 ◽  
Vol 71 (suppl_1) ◽  
pp. ons104-ons115 ◽  
Author(s):  
Kathleen Seidel ◽  
Jürgen Beck ◽  
Lennart Stieglitz ◽  
Philippe Schucht ◽  
Andreas Raabe
Keyword(s):  
Motor Neurons ◽  
Evoked Potential ◽  
Primary Motor Cortex ◽  
Motor Evoked Potential ◽  
National Institutes Of Health ◽  
Motor Deficit ◽  
Motor Threshold ◽  
Motor Mapping ◽  
Low Threshold ◽  
A Minor

Abstract BACKGROUND: Microsurgery within eloquent cortex is a controversial approach because of the high risk of permanent neurological deficit. Few data exist showing the relationship between the mapping stimulation intensity required for eliciting a muscle motor evoked potential and the distance to the motor neurons; furthermore, the motor threshold at which no deficit occurs remains to be defined. OBJECTIVE: To evaluate the safety of low threshold motor evoked potential mapping for tumor resection close to the primary motor cortex. METHODS: Fourteen patients undergoing tumor surgery were included. Motor threshold was defined as the stimulation intensity that elicited motor evoked potentials from target muscles (amplitude &gt; 30 μV). Monopolar high-frequency motor mapping with train-of-5 stimuli (HF-TOF; pulse duration = 500 microseconds; interstimulus interval = 4.0 milliseconds; frequency = 250 Hz) was used to determine motor response--negative sites where incision and dissection could be performed. At sites negative to 3-mA HF-TOF stimulation, the tumor was resected. RESULTS: HF-TOF mapping localized the motor neurons within the precentral gyrus by using variable, low-stimulation intensities. The lowest motor thresholds after final resection ranged from 3 to 6 mA, indicating close proximity of motor neurons. Postoperatively, 12 patients had no new motor deficit, 1 patient had a minor new temporary deficit (M4+, National Institutes of Health Stroke Scale 1), and another patient had a minor new permanent deficit (M4+, National Institutes of Health Stroke Scale 2). Thirteen patients had complete or gross total resection. CONCLUSION: These preliminary data demonstrate that a monopolar HF-TOF threshold &gt; 3 mA was not associated with a significant new motor deficit.

scholarly journals Dynamic Changes and Prognostic Value of Gut Microbiota-Dependent Trimethylamine-N-Oxide in Acute Ischemic Stroke

2020 ◽  
Vol 11 ◽  
Author(s):  
Chuhong Tan ◽  
Huidi Wang ◽  
Xuxuan Gao ◽  
Ruoting Xu ◽  
Xiuli Zeng ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Gut Microbiota ◽  
Acute Ischemic Stroke ◽  
Prognostic Value ◽  
Dynamic Changes
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