Intraoperative neuromonitoring of visual evoked potentials in a pregnant patient with meningioma: a case report.

Background: Meningioma in the parasellar region may lead to visual impairment, so intraoperative neurological monitoring is essential for enucleation surgery. However, intraoperative neurological monitoring in pregnant women is challenging, as the anesthesia management must consider the effects and risks to the fetus. Remimazolam is a newly introduced intravenous anesthetic that has little effect on blood pressure. However, the effects of remimazolam on intraoperative neuromonitoring are little known. We treated a pregnant patient with parasellar meningioma who developed visual impairment, using remimazolam for anesthesia and intraoperative neurophysiological monitoring of the visual evoked potential.

Case Presentation: A 34-year-old woman who was 20 weeks pregnant presented with visual acuity disturbances. Neuroimaging demonstrated a parasellar meningioma, and rapid tumor growth and worsening of symptoms subsequently occurred. Craniotomy for tumor removal was performed under anesthesia with remimazolam, which allowed monitoring of the visual evoked potentials. Her visual acuity was restored postoperatively, and no adverse events occurred in the fetus.

Conclusion: Our experience with intraoperative neuromonitoring of a pregnant woman in the third trimester showed that anesthesia with remimazolam allows safe brain surgery combined with intraoperative visual evoked potential monitoring. Further research is needed to determine the effects of remimazolam on the fetus, as well as the safe dosage and duration of exposure.