Which Muscles Should Be Used in Assessment of the Level of Neuromuscular Blockade during Intraoperative Motor- Evoked Potentials (MEPs) Monitoring? : Comparison between the Abductor Pollicis Brevis Muscle and the Anterior Tibial Muscle

2002 ◽  
Vol 96 (Sup 2) ◽  
pp. A295
Author(s):  
Tetsuya Kawabata ◽  
Manabu Kakinohana ◽  
Seiya Nakamura ◽  
Kazuhiro Sugahara
Keyword(s):  
Evoked Potentials ◽  
Neuromuscular Blockade ◽  
Motor Evoked Potentials ◽  
Abductor Pollicis Brevis ◽  
Anterior Tibial Muscle ◽  
Anterior Tibial ◽  
Abductor Pollicis Brevis Muscle

Quantification of motor pathways to the pelvic floor in humans

1991 ◽  
Vol 260 (5) ◽  
pp. G720-G723 ◽  
Author(s):  
J. Herdmann ◽  
K. Bielefeldt ◽  
P. Enck
Keyword(s):  
Pelvic Floor ◽  
Evoked Potentials ◽  
Anal Sphincter ◽  
External Anal Sphincter ◽  
Motor Evoked Potentials ◽  
Motor Innervation ◽  
Anterior Tibial Muscle ◽  
Motor Pathways ◽  
Anterior Tibial ◽  
Stimulation Of

The motor innervation of the pelvic floor plays a major role in defecation disorders such as fecal incontinence. It consists of central motor pathways and peripheral nerve fibers. Transcranial magnetoelectric stimulation of the brain and magnetoelectric stimulation of the lumbosacral motor roots were performed in 10 healthy volunteers. Motor evoked potentials were recorded from the external anal sphincter. This procedure allowed differentiation between a predominantly central and a solely peripheral component of the motor innervation of the external and sphincter. To compare these recordings with well-established data, motor evoked potentials were also recorded from the anterior tibial muscle. The central motor conduction time was 20.9 +/- 2.4 ms to the external anal sphincter and 14.8 +/- 2.3 ms to the anterior tibial muscles. Central motor conduction velocities were 40.7 +/- 5.2 and 55.5 +/- 7.6 m/s, respectively. This showed that conduction in the central fibers to the external anal sphincter was significantly slower than in those to the anterior tibial muscle. We conclude 1) that magnetoelectric stimulation allows differentiation between central and peripheral portions of the motor innervation of the pelvic floor, and 2) that central motor pathways innervating the pelvic floor differ significantly in their physiological properties from those innervating limb muscles.

The Effect of Etomidate on Motor Evoked Potentials Induced by Transcranial Magnetic Stimulation in the Monkey

Neurosurgery ◽  
1990 ◽  
Vol 27 (6) ◽  
pp. 936-942 ◽  
Author(s):  
Ramsis F. Ghaly ◽  
James L. Stone ◽  
Walter J. Levy ◽  
Peter Roccaforte ◽  
Edward B. Brunner
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Evoked Potentials ◽  
Total Dose ◽  
Magnetic Stimulation ◽  
Motor Evoked Potentials ◽  
Mean Amplitude ◽  
Abductor Hallucis ◽  
Abductor Pollicis Brevis ◽  
Hypnotic Agent ◽  
The Mean

Abstract Etomidate (ET) is a known hypnotic agent in neuroanesthesia. This study was designed to examine the reliability of motor evoked potentials (MEPs) after transcranial magnetic stimulation in monkeys anesthetized intravenously with ET. The ET regimen was as follows: an initial dose (0.5 mg/kg) followed by 13 doses (0.2 mg/kg every 6-12 min; mean, 8.0 ± 1.3 min). The total dose administered was 3.1 mg/kg. The magnetic coil was placed over the MEP scalp stimulation region. Evoked electromyographic responses were recorded from the contralateral abductor pollicis brevis (APB) and abductor hallucis (AH) muscles of the fore- and hindlimbs, respectively. Reproducible MEP responses were consistently recorded while the animal was under total ET anesthesia. The coil demography was altered and the MEP scalp topography was moderately reduced by ET injections. Significant threshold elevation was noted after a total dose of 1.7 mg/kg for APB responses and 0.5 mg/kg for AH responses (P < 0.05). Marked prolongation of latency was observed after a dose of 0.5 mg/kg for APB MEPs and 2.5 mg/kg for AH MEPs (P < 0.05). MEP amplitude responses showed marked variability. Repeated doses of ET produced a mean threshold rise of 14 to 28% for the APB and 19 to 29% for the AH. The mean latency delay was 5 to 11% for the APB and 0.5 to 8% for the AH, while the mean amplitude depression was 24 to 59% for the APB and 15 to 50% for the AH. Apparent seizure activity or abnormalities in behavior and feeding were not noted over a 1-year period. We conclude that monitoring of MEPs induced by transcranial magnetic stimulation under ET anesthesia is feasible. Clear MEP responses can be maintained under ET anesthesia. ET caused alterations in MEPs induced by transcranial magnetic stimulation, and awareness of such changes is important. Further investigation in humans is recommended.

scholarly journals Transcranial motor-evoked potentials for prediction of postoperative neurologic and motor deficit following surgery for thoracolumbar scoliosis

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Samuel M. Miller ◽  
Sean W. Donegan ◽  
Niesha Voigt ◽  
Adam E.M. Eltorai ◽  
Alan H. Daniels ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Vastus Lateralis ◽  
Information Criterion ◽  
Motor Deficit ◽  
Scoliosis Surgery ◽  
Abductor Pollicis Brevis ◽  
Lower Extremity Weakness ◽  
Before And After ◽  
Transcranial Motor Evoked Potentials

Transcranial motor-evoked potentials (TcMEPs) are used to monitor the descending motor pathway during scoliosis surgery. By comparing potentials before and after correction, surgeons may prevent postoperative functional loss in distal muscles. There is currently no consensus as to which muscles should be monitored. The purpose of this study is to determine the least invasive monitoring protocol with the best localization of potential neurologic deficit. A retrospective review of 125 patients with TcMEP monitoring during surgery for thoracolumbar scoliosis between 2008 and 2015 was conducted. 18 patients had postoperative neurologic consult due to deficit. The remaining 107 patients were a consecutive cohort without postoperative neurologic consult. TcMEPs were recorded from vastus lateralis (VL), tibialis anterior (TA), peroneus longus (PL), adductor hallucis (AH) and abductor pollicis brevis (APB) bilaterally. The effectiveness of each muscle combination was evaluated independently and then compared to other combinations using Akaike Information Criterion (AIC). Monitoring of VL, TA, PL, and AH yielded sensitivity of 77.8% and specificity of 92.5% (AIC=66.7). Monitoring of TA, PL and AH yielded sensitivity of 77.8% and specificity of 94.4% (AIC=62.4). Monitoring of VL, TA and PL yielded sensitivity of 72.2% and specificity of 93.5% (AIC=70.1). Monitoring of TA and PL yielded sensitivity of 72.2% and specificity of 96.3% (AIC=63.9). TcMEP monitoring of TA, PL, and AH provided the highest sensitivity and specificity and best predictive power for postoperative lower extremity weakness.

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