82. Motor evoked potentials are very sensitive to blood pressure in insular glioma surgery: A case report

2013 ◽  
Vol 124 (11) ◽  
pp. e207
Author(s):  
C. Arcaro ◽  
V. Tramontano ◽  
F. Sala
Keyword(s):  
Blood Pressure ◽  
Case Report ◽  
Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Glioma Surgery

scholarly journals A novel threshold criterion in transcranial motor evoked potentials during surgery for gliomas close to the motor pathway

2016 ◽  
Vol 125 (4) ◽  
pp. 795-802 ◽  
Author(s):  
Tammam Abboud ◽  
Miriam Schaper ◽  
Lasse Dührsen ◽  
Cindy Schwarz ◽  
Nils Ole Schmidt ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Tumor Resection ◽  
Threshold Level ◽  
Neurological Deterioration ◽  
Motor Deficit ◽  
Percentage Increase ◽  
Glioma Surgery ◽  
Leg Muscles ◽  
Threshold Criterion

OBJECTIVE Warning criteria for monitoring of motor evoked potentials (MEP) after direct cortical stimulation during surgery for supratentorial tumors have been well described. However, little is known about the value of MEP after transcranial electrical stimulation (TES) in predicting postoperative motor deficit when monitoring threshold level. The authors aimed to evaluate the feasibility and value of this method in glioma surgery by using a new approach for interpreting changes in threshold level involving contra- and ipsilateral MEP. METHODS Between November 2013 and December 2014, 93 patients underwent TES-MEP monitoring during resection of gliomas located close to central motor pathways but not involving the primary motor cortex. The MEP were elicited by transcranial repetitive anodal train stimulation. Bilateral MEP were continuously evaluated to assess percentage increase of threshold level (minimum voltage needed to evoke a stable motor response from each of the muscles being monitored) from the baseline set before dural opening. An increase in threshold level on the contralateral side (facial, arm, or leg muscles contralateral to the affected hemisphere) of more than 20% beyond the percentage increase on the ipsilateral side (facial, arm, or leg muscles ipsilateral to the affected hemisphere) was considered a significant alteration. Recorded alterations were subsequently correlated with postoperative neurological deterioration and MRI findings. RESULTS TES-MEP could be elicited in all patients, including those with recurrent glioma (31 patients) and preoperative paresis (20 patients). Five of 73 patients without preoperative paresis showed a significant increase in threshold level, and all of them developed new paresis postoperatively (transient in 4 patients and permanent in 1 patient). Eight of 20 patients with preoperative paresis showed a significant increase in threshold level, and all of them developed postoperative neurological deterioration (transient in 4 patients and permanent in 4 patients). In 80 patients no significant change in threshold level was detected, and none of them showed postoperative neurological deterioration. The specificity and sensitivity in this series were estimated at 100%. Postoperative MRI revealed gross-total tumor resection in 56 of 82 patients (68%) in whom complete tumor resection was attainable; territorial ischemia was detected in 4 patients. CONCLUSIONS The novel threshold criterion has made TES-MEP a useful method for predicting postoperative motor deficit in patients who undergo glioma surgery, and has been feasible in patients with preoperative paresis as well as in patients with recurrent glioma. Including contra- and ipsilateral changes in threshold level has led to a high sensitivity and specificity.

Predictive Value and Safety of Intraoperative Neurophysiological Monitoring With Motor Evoked Potentials in Glioma Surgery

Neurosurgery ◽  
2011 ◽  
Vol 70 (5) ◽  
pp. 1060-1071 ◽  
Author(s):  
Sandro M. Krieg ◽  
Ehab Shiban ◽  
Doris Droese ◽  
Jens Gempt ◽  
Niels Buchmann ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Predictive Value ◽  
Motor System ◽  
Motor Evoked Potentials ◽  
False Negative ◽  
Motor Deficit ◽  
Neurophysiological Monitoring ◽  
Glioma Surgery ◽  
Supratentorial Gliomas

Abstract BACKGROUND: Resection of gliomas in or adjacent to the motor system is widely performed with intraoperative neuromonitoring (IOM). Despite the fact that data on the safety of IOM are available, the significance and predictive value of the procedure are still under discussion. Moreover, cases of false-negative monitoring affect the surgeon's confidence in IOM. OBJECTIVE: To examine cases of false-negative IOM to reveal structural explanations. METHODS: Between 2007 and 2010, we resected 115 consecutive supratentorial gliomas in or close to eloquent motor areas using direct cortical stimulation for monitoring of motor evoked potentials (MEPs). The monitoring data were reviewed and related to new postoperative motor deficit and postoperative imaging. Clinical outcomes were assessed during follow-up. RESULTS: Monitoring of MEPs was successful in 112 cases (97.4%). Postoperatively, 30.3% of patients had a new motor deficit, which remained permanent in 12.5%. Progression-free follow-up was 9.7 months (range, 2 weeks-40.6 months). In 65.2% of all cases, MEPs were stable throughout the operation, but 8.9% showed a new temporary motor deficit, whereas 4.5% (5 patients) presented with permanently deteriorated motor function representing false-negative monitoring at first glance. However, these cases were caused by secondary hemorrhage, ischemia, or resection of the supplementary motor area. CONCLUSION: Continuous MEP monitoring provides reliable monitoring of the motor system, influences the course of operation in some cases, and has to be regarded as the standard for IOM of the motor system. In our series, we found no false-negative MEP results.

scholarly journals The influence of depth of anesthesia and blood pressure on muscle recorded motor evoked potentials in spinal surgery. A prospective observational study protocol

2021 ◽  
Author(s):  
Sebastiaan E. Dulfer ◽  
M. M. Sahinovic ◽  
F. Lange ◽  
F. H. Wapstra ◽  
D. Postmus ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Evoked Potentials ◽  
Study Protocol ◽  
False Positive ◽  
Motor Evoked Potentials ◽  
Neurological Injury ◽  
Neurophysiological Monitoring ◽  
Transcranial Electrical Stimulation ◽  
Depth Of Anesthesia ◽  
Registration Number

AbstractFor high-risk spinal surgeries, intraoperative neurophysiological monitoring (IONM) is used to detect and prevent intraoperative neurological injury. The motor tracts are monitored by recording and analyzing muscle transcranial electrical stimulation motor evoked potentials (mTc-MEPs). A mTc-MEP amplitude decrease of 50–80% is the most common warning criterion for possible neurological injury. However, these warning criteria often result in false positive warnings. False positives may be caused by inadequate depth of anesthesia and blood pressure on mTc-MEP amplitudes. The aim of this paper is to validate the study protocol in which the goal is to investigate the effects of depth of anesthesia (part 1) and blood pressure (part 2) on mTc-MEPs. Per part, 25 patients will be included. In order to investigate the effects of depth of anesthesia, a processed electroencephalogram (pEEG) monitor will be used. At pEEG values of 30, 40 and 50, mTc-MEP measurements will be performed. To examine the effect of blood pressure on mTc-MEPs the mean arterial pressure will be elevated from 60 to 100 mmHg during which mTc-MEP measurements will be performed. We hypothesize that by understanding the effects of depth of anesthesia and blood pressure on mTc-MEPs, the mTc-MEP monitoring can be interpreted more reliably. This may contribute to fewer false positive warnings. By performing this study after induction and prior to incision, this protocol provides a unique opportunity to study the effects of depths of anesthesia and blood pressure on mTc-MEPs alone with as little confounders as possible.Trial registration number NL7772.

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