caa a22 4500 606216707 CHVBK 20210128101104.0 cr unu---uuuuu 210128e20151101xx s 000 0 eng 10.1007/s00701-015-2571-9 doi (NATIONALLICENCE)springer-10.1007/s00701-015-2571-9 Predictive value of intraoperative neurophysiologic monitoring in assessing long-term facial function in grade IV vestibular schwannoma removal [Elektronische Daten] [Sérgio Duarte-Costa, Rui Vaz, Débora Pinto, Fernando Silveira, António Cerejo] Background: Despite routine use of intraoperative neuromonitoring in acoustic neuroma removal, its application in predicting long-term facial function is limited. Methods: Prospective recording of facial nerve function and subsequent review of intraoperative neurophysiologic data. Stimulation of the facial nerve was performed proximal and distal to the tumor locus after tumor removal with measurement of amplitude and latency responses in the orbicularis oculi and oris muscles. Prospective review of current facial nerve function was performed using the House-Brackmann (HB) scoring system. Good facial function was determined as HB I/II and HB III-VI was considered poor facial function. Minimum follow-up time was 15months, and averaged 40months. Results: Twenty-four grade IV acoustic neuromas (54% larger than 4cm) were completely removed from October 2008 to November 2013. Nine patients (37.5%) had HB I/II and 15 (62.5%) had HB III-VI. The poor prognosis group had a higher latency than the good prognosis group (p = 0.045). Lower proximal amplitude was detected in the poor prognosis group (p = 0.046). Lower proximal-to-distal amplitude ratio was also detected in the poor prognosis group (p = 0.052). Amplitude ratio cut-offs of 0.44 and 0.25 were able to predict poor prognosis with sensitivity of 0.73 and 0.4 and specificity of 0.78 and 1, respectively (p = 0.046). Conclusions: Lower proximal amplitude and proximal-distal amplitude ratio were previously reported as predictors of poor facial function in different sizes of vestibular schwannomas. We observed that the same applies specifically for large-sized, completely removed, grade IV tumors. Additionally, we describe a difference in proximal latency time between the good and poor prognosis groups, which was not previously reported. Springer-Verlag Wien, 2015 Acoustic neuroma nationallicence Proximal-to-distal amplitude ratio nationallicence Proximal amplitude nationallicence Proximal latency nationallicence Facial nerve nationallicence Duarte-Costa Sérgio Faculty of Medicine, University of Porto, Rua Sto António, n°88 São Mateus, Vila Nova Famalicão, 4765-773, Porto, Portugal aut Vaz Rui Faculty of Medicine, University of Porto, Rua Sto António, n°88 São Mateus, Vila Nova Famalicão, 4765-773, Porto, Portugal aut Pinto Débora Neurophysiology Unit of the Department of Neurology, Centro Hospitalar São João, Porto, Portugal aut Silveira Fernando Neurophysiology Unit of the Department of Neurology, Centro Hospitalar São João, Porto, Portugal aut Cerejo António Department of Neurosurgery, Centro Hospitalar São João, Porto, Portugal aut Acta Neurochirurgica Springer Vienna 157/11(2015-11-01), 1991-1998 0001-6268 157:11<1991 2015 157 701 https://doi.org/10.1007/s00701-015-2571-9 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00701-015-2571-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Duarte-Costa Sérgio Faculty of Medicine, University of Porto, Rua Sto António, n°88 São Mateus, Vila Nova Famalicão, 4765-773, Porto, Portugal aut NATIONALLICENCE 700 1- Vaz Rui Faculty of Medicine, University of Porto, Rua Sto António, n°88 São Mateus, Vila Nova Famalicão, 4765-773, Porto, Portugal aut NATIONALLICENCE 700 1- Pinto Débora Neurophysiology Unit of the Department of Neurology, Centro Hospitalar São João, Porto, Portugal aut NATIONALLICENCE 700 1- Silveira Fernando Neurophysiology Unit of the Department of Neurology, Centro Hospitalar São João, Porto, Portugal aut NATIONALLICENCE 700 1- Cerejo António Department of Neurosurgery, Centro Hospitalar São João, Porto, Portugal aut NATIONALLICENCE 773 0- Acta Neurochirurgica Springer Vienna 157/11(2015-11-01), 1991-1998 0001-6268 157:11<1991 2015 157 701