Despite improvements in microsurgical technique and the use of intraoperative electrophysiological monitoring, the potential for facial and cochlear nerve injury remains a possibility in the resection of vestibular schwannomas (VS).
Vestibular schwannoma surgery complications vary as expected by treatment modality, with cerebrospinal fluid leak, tinnitus, and trigeminal symptoms being among the most common complications following microsurgery 1).
In 333 patients after microsurgery (Koos grading scale 1: 12, grade 2: 34, grade 3: 62, and grade 4: 225) permanent trigeminal nerve dysfunction was found in 1% 2).
In large/compressive, trigeminal nerve deficit has to be sought to avoid corneal complications in particular. Trigeminal hypoesthesia occurs preoperatively in about half of the cases. It remains relatively stable after tumor removal, but there appears to be an increased rate of absent corneal reflex and neurotrophic keratitis postoperatively. Karkas et al. were able to correlate pre/postoperative trigeminal hypoesthesia with pre/postoperative MRI findings 3).