Background: Fosaprepitant [Emend®], a neurokinin type-1 [NK-1] receptor antagonist, is a highly effective for the prophylaxis of postoperative nausea and vomiting [PONV] after general anesthesia; it is particularly effective in patients undergoing neurosurgical procedures. Based on the widespread distribution of NK-1 receptors in the central and peripheral nervous systems, we sought to determine whether fosaprepitant administration would interfere with commonly used intraoperative neurophysiologic monitoring modalities during general anesthesia.Methods: Eleven patients having propofol-based general anesthesia for interventional neuroradiology procedures were administered 150 mg fosaprepitant intravenously after baseline electroencephalogram [EEG], transcranial motor evoked potential [TcMEP], and somatosensory evoked potential [SSEP] recordings were obtained. Recordings of these neuromonitoring modalities at 30, 60, and 90 min after fosaprepitant administration were compared to baseline.Results: Fosaprepitant did not have a significant effect on SSEP/ TcMEP amplitudes or latencies, or on TcMEP morphology. There were also no changes in EEG voltage, frequency, or symmetry. Conclusion:Fosaprepitant does not appear to markedly interfere with SSEP, TcMEP, or EEG neuromonitoring modalities during propofol-based general anesthesia.