Related Experiment Video
Updated: May 31, 2026
Assessing Primary Motor Cortex Excitability and Excitability Modulation by Pairing Transcranial Magnetic Stimulation with Electromyography
Published on: October 7, 2025
[Adverse events during transcranial muscle evoked potential monitoring]
Yoshie Kuwahara1, Shima Taguchi, Masahiko Kuroda
1Department of Anesthesiology and Critical Care, Hiroshima University Hospital, Hiroshima 734-8551.
Background:
Transcranial muscle evoked potential (TC-MsEP) monitoring is available to assess spinal cord motor tract function for preventing paralysis in spine surgery. Recently, the quality of monitoring has improved. However, adverse events such as torn tracheal tube, bitten tongue, and mandibular fracture are reported.
Methods:
We reviewed retrospectively adverse events with TC-MsEP monitoring by Multipulse D-185 (Digitimer Ltd., the U.K.) during spine surgery in our hospital. In addition, we compared the number of cases with transformed tracheal tubes in cases using Multipulse D-185 and in cases using the other stimulation device.
Results:
Since June 2007, Multipulse D-185 is applied as a stimulating device of TC-MsEP, and we experienced two adverse events of lasceration of tongue and teeth dislocation. There was a significant difference (P=0.02) in the number of transformed tracheal tube between Multipulse D-185 (11 of 20) and the other stimulation device (2 of 19).
Conclusions:
It seems that two adverse events were due to excessive masseter muscles contraction with TC-MsEP monitoring. Prevention for bite injury and ventilation strategy for tube occlusion or stenosis using Multipulse D-185 for TC-MsEP are necessary.
Insights
Transcranial muscle evoked potential (TC-MsEP) monitoring aids spinal cord function assessment during surgery. However, the Multipulse D-185 device increased adverse events like tracheal tube issues and bite injuries due to masseter muscle contraction.
Area of Science:
- Neurosurgery
- Spinal Cord Monitoring
- Anesthesiology
Background:
- Transcranial muscle evoked potential (TC-MsEP) monitoring assesses spinal cord motor tract function to prevent paralysis during spine surgery.
- Recent advancements have improved TC-MsEP monitoring quality.
- However, adverse events including tracheal tube damage, tongue biting, and mandibular fractures have been reported.
Observation:
- A retrospective review of adverse events associated with TC-MsEP monitoring using the Multipulse D-185 device during spine surgery was conducted.
- The study compared the incidence of tracheal tube transformation between the Multipulse D-185 and other stimulation devices.
- Two specific adverse events, tongue laceration and teeth dislocation, were noted with the Multipulse D-185.
Findings:
- The Multipulse D-185 device was associated with a significantly higher rate of tracheal tube transformation (11 of 20 cases) compared to other devices (2 of 19 cases; P=0.02).
- Adverse events, including tongue laceration and teeth dislocation, were attributed to excessive masseter muscle contraction induced by TC-MsEP monitoring.
- The incidence of tracheal tube issues was significantly higher with the Multipulse D-185.
Implications:
- The findings suggest a need for preventative strategies against bite injuries during TC-MsEP monitoring.
- Development of specific ventilation strategies is crucial to manage potential tube occlusion or stenosis when using the Multipulse D-185.
- Enhanced safety protocols are required for TC-MsEP monitoring, particularly with the Multipulse D-185 device, to mitigate risks of adverse events.
