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Non-invasive Assessment of Changes in Corticomotoneuronal Transmission in Humans
Published on: May 24, 2017
Motor-evoked potentials (MEP) during brainstem surgery to preserve corticospinal function.
Johannes Sarnthein1, Oliver Bozinov, Angelina Graziella Melone
1Klinik für Neurochirurgie, UniversitätsSpital Zürich, Switzerland. johannes.sarnthein@usz.ch
Acta Neurochirurgica
|June 11, 2011
Summary
Motor-evoked potentials (MEPs) monitoring during brainstem surgery helps prevent motor deficits. Adjusting surgical strategy based on MEPs led to good motor outcomes in most patients, highlighting MEPs
Area of Science:
- Neurosurgery
- Neurophysiology
Background:
- Brainstem surgery carries a risk of corticospinal tract (CST) damage.
- Motor-evoked potentials (MEPs) are used intraoperatively to monitor CST function.
- Standardized warning criteria for MEPs in brainstem surgery are needed.
Observation:
- 104 patients undergoing brainstem microsurgical resection were analyzed.
- MEP monitoring involved maintaining a constant response amplitude.
- Deterioration criteria included a ≥20 mA threshold elevation or <50% amplitude drop.
Findings:
- 39 patients had MEP deterioration; 16 developed new paresis (41% risk).
- 11 of 18 patients with new early postoperative paresis improved by discharge.
- Stable intraoperative MEPs did not always prevent postoperative motor deficits.
Implications:
- Adjusting surgical strategy based on MEPs improved motor outcomes in 33/39 patients.
- MEP monitoring is valuable for preventing motor deficits in complex brainstem surgeries.
- Further refinement of MEP warning criteria is warranted for brainstem procedures.
