GAMMA KNIFE SURGERY FOR FACIAL NERVE SCHWANNOMAS
- 1 May 2007
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Neurosurgery
- Vol. 60 (5), 853-859
- https://doi.org/10.1227/01.neu.0000249282.46514.da
Abstract
Radical resection of facial nerve schwannomas classically implies a high risk of severe facial palsy. Owing to the rarity of facial palsy after gamma knife surgery (GKS) of vestibular schwannomas, functional evaluation after GKS seems rational in this specific group of patients. To our knowledge, no previous similar evaluation exists in the literature. Of 1783 schwannomas of the cerebellopontine angles treated by GKS at Timone University Hospital between July 1992 and May 2003, 11 were diagnosed as originating from the facial nerve. Criteria for this diagnosis were the involvement of the tympanic or mastoid segment of the facial nerve (n = 9) and/or preoperative observation of a facial nerve deficit that had occurred during previous microsurgery (two patients). The rare occurrence of facial palsy after vestibular schwannoma radiosurgery, usually within 18 months of treatment, has been considered only in the patients with more than 2 years of follow-up (n = 9). Six of these patients experienced a previous spontaneous facial palsy on one (n = 4) or several occasions (n = 2). A normal motor facial function was observed in only three patients before GKS (House-Brackmann Grade II in six patients, Grade III in one patient, Grade IV in one patient). The median follow-up period was 39 months (range, 18–84 mo). At the time of the last follow-up examination, no patients had developed a new facial palsy or experienced deterioration of a preexisting facial palsy and three patients had improvement of a preoperative facial palsy. Ten out of the 11 tumors are stable or decreased in size; in the other, a microsurgical resection of the tumor had been recommended owing to the development of a cyst. Clinical management owing to the specificity and heterogeneity of this group of patients has required the development of an original classification of four anatomic subtypes presenting different clinical and surgical difficulties. This first study demonstrates that radiosurgery allows treatment of these patients while preserving normal motor facial function. Such an advantage should lead to the consideration of GKS as a first treatment option for small- to medium-size facial nerve schwannomas.Keywords
This publication has 12 references indexed in Scilit:
- Schwannomes du nerf facial intracrânien: À propos de 7 observationsNeurochirurgie, 2006
- Intratemporal Facial Nerve Schwannoma: A Management DilemmaOtology & Neurotology, 2005
- Facial nerve schwannomas: A report of four cases and a review of the literatureAmerican Journal of Otolaryngology, 2004
- Gamma knife radiosurgical management of petroclival meningiomas results and indicationsActa Neurochirurgica, 2003
- Gamma Knife Radiosurgery for Acoustic TumorsTechniques in Neurosurgery, 2003
- New and Modified Reporting Systems from the Consensus Meeting on Systems for Reporting Results in Vestibular SchwannomaOtology & Neurotology, 2003
- Linear accelerator radiosurgery for nonacoustic schwannomasInternational Journal of Radiation Oncology*Biology*Physics, 1999
- Hearing preservation in patients undergoing vestibular schwannoma surgery: comparison of middle fossa and retrosigmoid approachesJournal of Neurosurgery, 1998
- Conservative Management of Acoustic Neuroma: An Outcome StudyNeurosurgery, 1996
- Hearing Preservation in Unilateral Acoustic Neuroma SurgeryAnnals of Otology, Rhinology & Laryngology, 1988