Effect of Isoflurane on Motor-evoked Potentials Induced by Direct Electrical Stimulation of the Exposed Motor Cortex with Single, Double, and Triple Stimuli in Rats

1996 ◽  
Vol 85 (5) ◽  
pp. 1176-1183 ◽  
Author(s):  
Masahiko Kawaguchi ◽  
Kiyoshi Shimizu ◽  
Hitoshi Furuya ◽  
Takanori Sakamoto ◽  
Hideyuki Ohnishi ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Motor Cortex ◽  
Evoked Potentials ◽  
Success Rate ◽  
Motor Evoked Potentials ◽  
Single Pulse ◽  
Dependent Manner ◽  
Dose Dependent ◽  
Pulse Stimulation ◽  
Stimulation Of

Background The clinical application of intraoperative motor-evoked potentials (MEPs) has been hampered by their sensitivity to anesthetics. Recently, to overcome anesthetic-induced depression of myogenic MEPs, multiple stimulus setups with a paired or a train of pulses for stimulation of the motor cortex were reported. However, the effects of anesthetics on MEPs induced by these stimulation techniques are unknown. Methods Bipolar electrical stimulation of the left motor cortex was carried out in 15 rats anesthetized with thiopental while the compound muscle action potentials were recorded from the contralateral hind limb. After recording of the MEP in response to the single-shock stimulation of the motor cortex, paired pulses (double pulses) or a train of three pulses (triple pulses) with an interstimulus interval of each pulse at 0.3, 0.5, 1.0, 1.5, and 2.0 ms were applied. After control MEP recording, isoflurane was administered at a concentration of 0.25 minimum alveolar anesthetic concentration (MAC), 0.5 MAC, 0.75 MAC, and 1.0 MAC, and the effects of isoflurane on the MEPs induced by single, double, and triple pulses were evaluated. Results In all animals, distinct baseline MEPs were recorded. During the administration of 0.25 MAC and 0.5 MAC isoflurane, MEPs induced by stimulation with a single pulse could be recorded in 87% and 33% of animals, respectively, and MEP amplitude was significantly reduced in a dose-dependent manner. During the administration of 0.75 MAC isoflurane, MEPs after single-pulse stimulation could not be recorded in any animals. By stimulating with paired or triple pulses, the success rate of MEP recording and MEP amplitude significantly increased compared with those after single pulse before and during the administration of isoflurane. Both the success rate of MEP recording and MEP amplitude after double- and triple-pulse stimulation decreased significantly in a dose-dependent manner during the administration of isoflurane. Conclusions Application of double or triple stimulation of the motor cortex increases the success rate of MEP recording and its amplitude during isoflurane anesthesia in rats. However, these responses are suppressed by isoflurane in a dose-dependent manner.

Intraoperative Myogenic Motor Evoked Potentials Induced by Direct Electrical Stimulation of the Exposed Motor Cortex Under Isoflurane and Sevoflurane

1996 ◽  
Vol 82 (3) ◽  
pp. 593-599 ◽  
Author(s):  
Masahiko Kawaguchi ◽  
Takanori Sakamoto ◽  
Hideyuki Ohnishi ◽  
Kiyoshi Shimizu ◽  
Jun Karasawa ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Motor Cortex ◽  
Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Direct Electrical Stimulation ◽  
Stimulation Of

Tetanic stimulation of the pudendal nerve prior to transcranial electrical stimulation augments the amplitude of motor evoked potentials during pediatric neurosurgery

2021 ◽  
pp. 1-9
Author(s):  
Tsunenori Takatani ◽  
Yasushi Motoyama ◽  
Young-Soo Park ◽  
Taekyun Kim ◽  
Hironobu Hayashi ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Evoked Potentials ◽  
Success Rate ◽  
Pudendal Nerve ◽  
Pediatric Patients ◽  
Motor Evoked Potentials ◽  
Pediatric Neurosurgery ◽  
Transcranial Electrical Stimulation ◽  
Tetanic Stimulation ◽  
Stimulation Of

OBJECTIVE Reportedly, tetanic stimulation prior to transcranial electrical stimulation (TES) facilitates elicitation of motor evoked potentials (MEPs) by a mechanism involving increased corticomotoneuronal excitability in response to somatosensory input. However, the posttetanic MEP following stimulation of a pure sensory nerve has never been reported. Furthermore, no previous reports have described posttetanic MEPs in pediatric patients. The aim of this study was to investigate the efficacy of posttetanic MEPs in pediatric neurosurgery patients and to compare the effects on posttetanic MEP after tetanic stimulation of the sensory branch of the pudendal nerve versus the standard median and tibial nerves, which contain a mixture of sensory and motor fibers. METHODS In 31 consecutive pediatric patients with a mean age of 6.0 ± 5.1 years who underwent lumbosacral surgery, MEPs were elicited by TES without tetanic stimulation (conventional MEPs [c-MEPs]) and following tetanic stimulation of the unilateral median and tibial nerves (mt-MEPs) and the sensory branch of the pudendal nerve (p-MEP). Compound muscle action potentials were elicited from abductor pollicis brevis (APB), gastrocnemius (Gc), tibialis anterior (TA), and adductor hallucis (AH) muscles. The success rate of monitoring each MEP and the increases in the ratios of mt-MEP and p-MEP to c-MEP were investigated. RESULTS The success rate of monitoring p-MEPs was higher than those of mt-MEPs and c-MEPs (87.5%, 72.6%, and 63.3%, respectively; p < 0.01, adjusted by Bonferroni correction). The mean increase in the ratio of p-MEP to c-MEP for all muscles was significantly higher than that of mt-MEP to c-MEP (3.64 ± 4.03 vs 1.98 ± 2.23, p < 0.01). Subanalysis of individual muscles demonstrated significant differences in the increases in the ratios between p-MEP and mt-MEP in the APB bilaterally, as well as ipsilateral Gc, contralateral TA, and bilateral AH muscles. CONCLUSIONS Tetanic stimulation prior to TES can augment the amplitude of MEPs during pediatric neurosurgery, the effect being larger with pudendal nerve stimulation than tetanic stimulation of the unilateral median and tibial nerves. TES elicitation of p-MEPs might be useful in pediatric patients in whom it is difficult to elicit c-MEPs.

Intraoperative Myogenic Motor Evoked Potentials Induced by Direct Electrical Stimulation of the Exposed Motor Cortex Under Isoflurane and Sevoflurane

1996 ◽  
Vol 82 (3) ◽  
pp. 593-599 ◽  
Author(s):  
Masahiko Kawaguchi ◽  
Takanori Sakamoto ◽  
Hideyuki Ohnishi ◽  
Kiyoshi Shimizu ◽  
Jun Karasawa ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Motor Cortex ◽  
Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Direct Electrical Stimulation ◽  
Stimulation Of

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 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.

Sign in / Sign up

Export Citation Format

Share Document