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

Abstract Background: Meningiomas in the parasellar region leads to visual impairment, therefore intraoperative neurological monitoring is essential for enucleation surgery. However intraoperative neurological monitoring in pregnant women is challenging, as anesthesia management is required that considers the effects and risks to the fetus. Remimazolam is a newly introduced intravenous anesthetic, that has little effect on blood pressure. The effects of remimazolam on intraoperative neuromonitoring are little known. We treated a pregnant patient with parasellar meningioma who developed visual impairment, anesthesia was administered using remimazolam, 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, and the visual evoked potentials could be measured. Her visual acuity was restored postoperatively, and no adverse events occurred in the fetus. Conclusion: The intraoperative neuromonitoring of pregnant women showed that remimazolam may be useful for performing neurosurgical surgery combined with intraoperative neurological monitoring for pregnant women who are vulnerable to blood pressure fluctuations.