OBJECTIVE: To determine whether transcranial electrical stimulation-induced facial motor-evoked potential (FMEP) monitoring of the facial nerve (FN) during vestibular schwannoma (VS) tumor resection can predict both immediate and 1 year postoperative FN functional outcome. DESIGN: Prospective consecutive non-comparative observational case series. SETTING: Tertiary referral center. MAIN OUTCOME MEASURES: Facial function, immediate post operation and at 1 year using House-Brackmann (HB) grading scale. METHODS: The study included 367 consecutive patients (men 178; women 189; age 13-81 years) monitored during primary sporadic VS microsurgery between November 2002 and April 2015. Neurofibromatosis type II, revision surgery, previous radiotherapy treatment, preoperative facial nerve weakness, and non-VS cases were excluded retrospectively during analysis of data. Data of facial function were missing from eight patients at 1 year and were excluded. The correlation between the final-to-baseline FMEP ratio and immediate and 1 year facial nerve function was examined. RESULTS: Using logistic regression model, the cut-off points of FMEP ratio were 0.62 (PPV 0.96) and 0.59 (PPV 0.98) which predicted satisfactory FN function (HB grades 1 or 2) immediately postoperative and at 1 year after surgery, respectively. CONCLUSION: Transcranial electrical stimulation FMEP is a valuable tool for monitoring facial nerve function during resection of vestibular schwannoma. Maintaining a FMEP event-to-baseline ratio of 60% or greater is predictive of satisfactory long-term FN function.
OBJECTIVE: To determine whether transcranial electrical stimulation-induced facial motor-evoked potential (FMEP) monitoring of the facial nerve (FN) during vestibular schwannoma (VS) tumor resection can predict both immediate and 1 year postoperative FN functional outcome. DESIGN: Prospective consecutive non-comparative observational case series. SETTING: Tertiary referral center. MAIN OUTCOME MEASURES: Facial function, immediate post operation and at 1 year using House-Brackmann (HB) grading scale. METHODS: The study included 367 consecutive patients (men 178; women 189; age 13-81 years) monitored during primary sporadic VS microsurgery between November 2002 and April 2015. Neurofibromatosis type II, revision surgery, previous radiotherapy treatment, preoperative facial nerve weakness, and non-VS cases were excluded retrospectively during analysis of data. Data of facial function were missing from eight patients at 1 year and were excluded. The correlation between the final-to-baseline FMEP ratio and immediate and 1 year facial nerve function was examined. RESULTS: Using logistic regression model, the cut-off points of FMEP ratio were 0.62 (PPV 0.96) and 0.59 (PPV 0.98) which predicted satisfactory FN function (HB grades 1 or 2) immediately postoperative and at 1 year after surgery, respectively. CONCLUSION: Transcranial electrical stimulation FMEP is a valuable tool for monitoring facial nerve function during resection of vestibular schwannoma. Maintaining a FMEP event-to-baseline ratio of 60% or greater is predictive of satisfactory long-term FN function.
Authors: Tom Hendriks; Henricus P M Kunst; Maarten Huppelschoten; Jonne Doorduin; Mark Ter Laan Journal: Acta Neurochir (Wien) Date: 2020-03-07 Impact factor: 2.216
Authors: Ismail Taha; Antti Hyvärinen; Antti Ranta; Olli-Pekka Kämäräinen; Jukka Huttunen; Esa Mervaala; Heikki Löppönen; Tuomas Rauramaa; Antti Ronkainen; Juha E Jääskeläinen; Arto Immonen; Nils Danner Journal: Acta Neurochir (Wien) Date: 2019-09-07 Impact factor: 2.216