Intraoperative monitoring of motor evoked potentials during insular glioma surgery

2007 ◽  
Vol 118 (4) ◽  
pp. e78
Author(s):  
G. Neuloh ◽  
J. Schramm
Keyword(s):  
Evoked Potentials ◽  
Intraoperative Monitoring ◽  
Motor Evoked Potentials ◽  
Glioma Surgery

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.

Intraoperative monitoring of motor evoked potentials: A review of 116 cases

Neurology ◽  
1996 ◽  
Vol 47 (4) ◽  
pp. 999-1004 ◽  
Author(s):  
K. J. Nagle ◽  
R. G. Emerson ◽  
D. C. Adams ◽  
E. J. Heyer ◽  
D. P. Roye ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Intraoperative Monitoring ◽  
Motor Evoked Potentials

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.

INTRAOPERATIVE MONITORING OF TRANSCRANIAL ELECTRICAL MOTOR EVOKED POTENTIALS DURING SCOLIOSIS SURGERY

1999 ◽  
Vol 16 (2) ◽  
pp. 179
Author(s):  
Kyusang S. Lee ◽  
Jeffrey Cohen ◽  
Michael G. Neuwirth ◽  
Paul L. Kuflik ◽  
James G. Tucci ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Intraoperative Monitoring ◽  
Motor Evoked Potentials ◽  
Scoliosis Surgery
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