How Many Electromyography Channels Do We Need for Facial Nerve Monitoring?
- 1 June 2012
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Journal of Clinical Neurophysiology
- Vol. 29 (3), 226-229
- https://doi.org/10.1097/wnp.0b013e318257cabc
Abstract
Continuous electromyography (EMG) monitoring is a standard method for intraoperative monitoring of facial nerve function. Typically, only two or three bipolar channels are recorded from needle electrodes to detect pathologic activity, which may provide an incomplete sample. Therefore, we evaluated the influence of channel number on monitoring quality. The EMG data of 30 patients undergoing surgery for vestibular schwannoma were recorded using 9 bipolar channels from subdermal needle electrodes located in the orbicular oculi, oris, and nasal muscle. Pathologic A-train activity was evaluated in regard to correlation to postoperative nerve function. Channel combinations with different channel numbers were compared. A-train quantity showed high correlations to postoperative nerve function: Spearman rank correlation of 0.58 for 2, 0.61 for 3 channels. It increased further with every additional channel to 0.69 for all 9 channels (48% of variance accounted for). Single channels with more than one-third of total A-train activity (“hot spots”) were observed in 17 patients, which did not show consistent spatial patterns and could only be completely detected with a high number of channels. Few channels as used in conventional monitoring setups yield acceptable results. However, correlation between train time and postoperative functional results improves with every additional EMG channel.Keywords
This publication has 16 references indexed in Scilit:
- A Real-Time Monitoring System for the Facial NerveNeurosurgery, 2010
- Train time as a quantitative electromyographic parameter for facial nerve function in patients undergoing surgery for vestibular schwannomaJournal of Neurosurgery, 2007
- Hearing Preservation and Facial Nerve Outcomes in Vestibular Schwannoma Surgery: Results Using the Middle Cranial Fossa ApproachOtology & Neurotology, 2006
- Continuous electromyography monitoring of motor cranial nerves during cerebellopontine angle surgeryJournal of Neurosurgery, 2000
- Hearing preservation in acoustic neuroma surgery: middle fossa versus retrosigmoid approachAmerican Journal of Otolaryngology, 2000
- Intra-operative monitoring in acoustic neuroma surgeryNeurological Research, 1998
- Acoustic (loudspeaker) facial electromyographic monitoringNeurosurgery, 1986
- Preservation of facial function during removal of acoustic neuromasJournal of Neurosurgery, 1984
- Somatotopic Representation of Facial Muscles within the Facial Nucleus of the MouseBrain, Behavior and Evolution, 1984
- Motor Fibre Organization in the Intratemporal Portion of Cat and Rat Facial Nerve studied with the horseradish Peroxidase TechniqueActa Oto-Laryngologica, 1982