title: Intraoperative evoked facial muscle responses and recovery process of the facial nerve in acoustic neuroma surgery.
abstract: The prognostic value of intraoperative evoked facial muscle responses (EFMR) was studied and correlated with the recovery process of the facial nerve during a follow-up period of 18 months. The patients were classified into four groups according to EFMR amplitudes, group A (150 microV or greater, 190.8, SD28.9 microV, n = 24), group B (100-149 microV, 125.7, SD14.3 microV, n = 14), group C (50-99 microV, 79.0, SD17.0 microV, n = 13) and group D (less than 50 microV, 22.1, SD13.3 microV, n = 15). Significant improved facial function appeared at 3 months after the operation in group A, at 6 months in group B, at 9 months in group C and at 12 months in group D. The early postoperative facial function and facial outcome of groups A and B were significantly better than those of groups C and D. Our data revealed that the intraoperative EFMR amplitudes have more prognostic value in predicting the recovery process of the nerve than functional outcome.
authors.affiliation: Department of Neurosurgery, Hamamatsu University School of Medicine, Japan. yokoyama@hama-med.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Yokoyama
authors.forename: S
authors.initials: S
authors.lastname: Nishizawa
authors.forename: K
authors.initials: K
authors.lastname: Sugiyama
authors.forename: N
authors.initials: N
authors.lastname: Yokota
authors.forename: S
authors.initials: S
authors.lastname: Ohta
authors.forename: K
authors.initials: K
authors.lastname: Uemura
mesh_terms: D000704:Analysis of Variance; D016057:Evoked Potentials, Auditory, Brain Stem; D005154:Facial Nerve / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000503:physiopathology / Q000601:surgery*; D011182:Postoperative Care; D011379:Prognosis