Enhanced Precision in Personalized Intraoperative Monitoring of Facial Nerves: A Comparative Analysis of Functional MRI-Guided and Conventional Electrode Placement for Transcranial Motor-Evoked Potentials During Skull Base Surgery

Neuronavigation-assisted, fMRI-guided tfMEP reliably targets the individual M1 facial area and significantly lowers stimulation thresholds vs conventional C3/C4, without increasing susceptibility to threshold drift after CSF loss. This simple, adoptable workflow may enhance intraoperative decision making for facial nerve preservation. Larger multicenter studies are warranted to validate outcome prediction and refine threshold-based alarm criteria.