scholarly journals Measurement of motor evoked potentials following repetitive magnetic motor cortex stimulation during isoflurane or propofol anaesthesia

2003 ◽  
Vol 91 (4) ◽  
pp. 487-492 ◽  
Author(s):  
V. Rohde ◽  
G.A. Krombach ◽  
J.H. Baumert ◽  
I. Kreitschmann-Andermahr ◽  
M. Weinzierl ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Motor Cortex Stimulation

Motor Cortex Stimulation in a Three-Year-Old Child With Trigeminal Neuropathic Pain Caused by a Malignant Glioma in the Cerebellopontine Angle: Case Report

Neurosurgery ◽  
2011 ◽  
Vol 69 (2) ◽  
pp. E494-E496 ◽  
Author(s):  
Maxime Delavallee ◽  
Herbert Rooijakkers ◽  
Guus Koerts ◽  
Christian Raftopoulos
Keyword(s):  
Neuropathic Pain ◽  
Motor Cortex ◽  
Evoked Potentials ◽  
Malignant Glioma ◽  
Cerebellopontine Angle ◽  
Motor Evoked Potentials ◽  
Temporal Part ◽  
Motor Cortex Stimulation ◽  
Trigeminal Neuropathic Pain ◽  
Sensory Evoked

Abstract BACKGROUND AND IMPORTANCE: Motor cortex stimulation (MCS) is an accepted treatment in neuropathic pain syndromes. Use of MCS for trigeminal neuropathic pain (TNP) caused by a malignant glioma or in a child has not previously been reported in the literature. CLINICAL PRESENTATION: A 3-year-old boy presented to our department with a right temporal tumor with extension into the cavernous sinus and along the root of the trigeminal nerve up to the protuberance. Six weeks after removal of the temporal part of the tumor, the patient developed medically refractory trigeminal pain associated with tumor progression into the posterior fossa. We decided to remove the tumor from the cerebellopontine angle and residual tumor in the pericavernous area and then gave postoperative radio- and chemotherapy. Five months later, the patient developed unbearable refractory neuropathic pain characterized by a burning sensation in the first and second trigeminal areas. After a multidisciplinary discussion, MCS was recommended. We performed subdural MCS after localization of the central sulcus via anatomic landmarks, neuronavigation, peroperative sensory evoked potentials, and motor evoked potentials. The mother estimated a 75% reduction in the child's pain at 48 hours postoperatively, which continued until the child was pain-free. CONCLUSION: MCS is a minimally invasive surgical technique that seems to be a potential treatment for carefully selected children experiencing very severe and medically refractory neuropathic pain, even in the context of a neoplasm.

Transcranial electrical stimulation through screw electrodes for intraoperative monitoring of motor evoked potentials

2004 ◽  
Vol 100 (1) ◽  
pp. 155-160 ◽  
Author(s):  
Katsushige Watanabe ◽  
Takashi Watanabe ◽  
Akio Takahashi ◽  
Nobuhito Saito ◽  
Masafumi Hirato ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Motor Cortex ◽  
Evoked Potentials ◽  
Intraoperative Monitoring ◽  
Primary Motor Cortex ◽  
Motor Evoked Potentials ◽  
Transcranial Electrical Stimulation ◽  
Content Type ◽  
Motor Pathways ◽  
Fine Print

✓ The feasibility of high-frequency transcranial electrical stimulation (TES) through screw electrodes placed in the skull was investigated for use in intraoperative monitoring of the motor pathways in patients who are in a state of general anesthesia during cerebral and spinal operations. Motor evoked potentials (MEPs) were elicited by TES with a train of five square-wave pulses (duration 400 µsec, intensity ≤ 200 mA, frequency 500 Hz) delivered through metal screw electrodes placed in the outer table of the skull over the primary motor cortex in 42 patients. Myogenic MEPs to anodal stimulation were recorded from the abductor pollicis brevis (APB) and tibialis anterior (TA) muscles. The mean threshold stimulation intensity was 48 ± 17 mA for the APB muscles, and 112 ± 35 mA for the TA muscles. The electrodes were firmly fixed at the site and were not dislodged by surgical manipulation throughout the operation. No adverse reactions attributable to the TES were observed. Passing current through the screw electrodes stimulates the motor cortex more effectively than conventional methods of TES. The method is safe and inexpensive, and it is convenient for intraoperative monitoring of motor pathways.

scholarly journals Somatosensory cortical excitability changes precede those in motor cortex during human motor learning

2019 ◽  
Vol 122 (4) ◽  
pp. 1397-1405 ◽  
Author(s):  
Hiroki Ohashi ◽  
Paul L. Gribble ◽  
David J. Ostry
Keyword(s):  
Motor Cortex ◽  
Motor Learning ◽  
Evoked Potentials ◽  
Somatosensory Cortex ◽  
Somatosensory Evoked Potentials ◽  
Motor Skill ◽  
Cortical Excitability ◽  
Motor Evoked Potentials ◽  
Human Motor ◽  
Motor Cortical

Motor learning is associated with plasticity in both motor and somatosensory cortex. It is known from animal studies that tetanic stimulation to each of these areas individually induces long-term potentiation in its counterpart. In this context it is possible that changes in motor cortex contribute to somatosensory change and that changes in somatosensory cortex are involved in changes in motor areas of the brain. It is also possible that learning-related plasticity occurs in these areas independently. To better understand the relative contribution to human motor learning of motor cortical and somatosensory plasticity, we assessed the time course of changes in primary somatosensory and motor cortex excitability during motor skill learning. Learning was assessed using a force production task in which a target force profile varied from one trial to the next. The excitability of primary somatosensory cortex was measured using somatosensory evoked potentials in response to median nerve stimulation. The excitability of primary motor cortex was measured using motor evoked potentials elicited by single-pulse transcranial magnetic stimulation. These two measures were interleaved with blocks of motor learning trials. We found that the earliest changes in cortical excitability during learning occurred in somatosensory cortical responses, and these changes preceded changes in motor cortical excitability. Changes in somatosensory evoked potentials were correlated with behavioral measures of learning. Changes in motor evoked potentials were not. These findings indicate that plasticity in somatosensory cortex occurs as a part of the earliest stages of motor learning, before changes in motor cortex are observed. NEW & NOTEWORTHY We tracked somatosensory and motor cortical excitability during motor skill acquisition. Changes in both motor cortical and somatosensory excitability were observed during learning; however, the earliest changes were in somatosensory cortex, not motor cortex. Moreover, the earliest changes in somatosensory cortical excitability predict the extent of subsequent learning; those in motor cortex do not. This is consistent with the idea that plasticity in somatosensory cortex coincides with the earliest stages of human motor learning.

scholarly journals Training voluntary motor suppression with real-time feedback of motor evoked potentials

2015 ◽  
Vol 113 (9) ◽  
pp. 3446-3452 ◽  
Author(s):  
D. S. Adnan Majid ◽  
Christina Lewis ◽  
Adam R. Aron
Keyword(s):  
Motor Cortex ◽  
Evoked Potentials ◽  
Real Time ◽  
Motor Evoked Potentials ◽  
Single Pulse ◽  
High Temporal Resolution ◽  
Double Blind Study ◽  
Training Procedure ◽  
Double Blind ◽  
Control Response

Training people to suppress motor representations voluntarily could improve response control. We evaluated a novel training procedure of real-time feedback of motor evoked potentials (MEPs) generated by transcranial magnetic stimulation (TMS) over motor cortex. On each trial, a cue instructed participants to use a mental strategy to suppress a particular finger representation without overt movement. A single pulse of TMS was delivered over motor cortex, and an MEP-derived measure of hand motor excitability was delivered visually to the participant within 500 ms. In experiment 1, we showed that participants learned to reduce the excitability of a particular finger beneath baseline (selective motor suppression) within 30 min of practice. In experiment 2, we performed a double-blind study with 2 training groups (1 with veridical feedback and 1 with matched sham feedback) to show that selective motor suppression depends on the veridical feedback itself. Experiment 3 further demonstrated the importance of veridical feedback by showing that selective motor suppression did not arise from mere mental imagery, even when incentivized with reward. Thus participants can use real-time feedback of TMS-induced MEPs to discover an effective mental strategy for selective motor suppression. This high-temporal-resolution, trial-by-trial-feedback training method could be used to help people better control response tendencies and may serve as a potential therapy for motor disorders such as Tourette's and dystonia.

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