Learning from EMG: semi-automated grading of facial nerve function

2022 ◽  
Author(s):  
Magdalena Holze ◽  
Leonhard Rensch ◽  
Julian Prell ◽  
Christian Scheller ◽  
Sebastian Simmermacher ◽  
...  
Keyword(s):  
Machine Learning ◽  
Facial Nerve ◽  
Objective Evaluation ◽  
Surface Emg ◽  
Nerve Function ◽  
Facial Nerve Function ◽  
Subjective Impression ◽  
Study Approach ◽  
Automated Grading ◽  
Good Differentiation

AbstractThe current grading of facial nerve function is based on subjective impression with the established assessment scale of House and Brackmann (HB). Especially for research a more objective method is needed to lower the interobserver variability to a minimum. We developed a semi-automated grading system based on (facial) surface EMG-data measuring the facial nerve function of 28 patients with vestibular schwannoma surgery. The sEMG was recorded preoperatively, postoperatively and after 3–12 months. In addition, the HB grade was determined. After manual selection and preprocessing, the data were subjected to machine learning classificators (Logistic regression, SVM and KNN). Lateralization indices were calculated and multivariant machine learning analysis was performed according to three scenarios [differentiation of normal (1) and slight (2) vs. impaired facial nerve function and classification of HB 1-3 (3)]. The calculated AUC for each scenario showed overall good differentiation capability with a median AUC of 0.72 for scenario 1, 0.91 for scenario 2 and multiclass AUC of 0.74 for scenario 3. This study approach using sEMG and machine learning shows feasibility regarding facial nerve grading in perioperative VS-surgery setting. sEMG may be a viable alternative to House Brackmann regarding objective evaluation of facial function especially for research purposes.

Intraoperative facial motor evoked potential monitoring for pontine cavernous malformation resection

2020 ◽  
Vol 132 (1) ◽  
pp. 265-271
Author(s):  
Ridzky Firmansyah Hardian ◽  
Tetsuya Goto ◽  
Yu Fujii ◽  
Kohei Kanaya ◽  
Tetsuyoshi Horiuchi ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Cavernous Malformation ◽  
Motor Evoked Potentials ◽  
Motor Evoked Potential ◽  
Warning Signs ◽  
Constant Current ◽  
Karnofsky Performance Scale ◽  
Nerve Function ◽  
Facial Nerve Function ◽  
Cavernous Malformations

OBJECTIVEThe aim of this study was to predict postoperative facial nerve function during pontine cavernous malformation surgery by monitoring facial motor evoked potentials (FMEPs).METHODSFrom 2008 to 2017, 10 patients with pontine cavernous malformations underwent total resection via the trans–fourth ventricle floor approach with FMEP monitoring. House-Brackmann grades and Karnofsky Performance Scale (KPS) scores were obtained pre- and postoperatively. The surgeries were performed using one of 2 safe entry zones into the brainstem: the suprafacial triangle and infrafacial triangle approaches. Six patients underwent the suprafacial triangle approach, and 4 patients underwent the infrafacial triangle approach. A cranial peg screw electrode was used to deliver electrical stimulation for FMEP by a train of 4 or 5 pulse anodal constant current stimulation. FMEP was recorded from needle electrodes on the ipsilateral facial muscles and monitored throughout surgery by using a threshold-level stimulation method.RESULTSFMEPs were recorded and analyzed in 8 patients; they were not recorded in 2 patients who had severe preoperative facial palsy and underwent an infrafacial triangle approach. Warning signs appeared in all patients who underwent the suprafacial triangle approach. However, after temporarily stopping the procedures, FMEP findings during surgery showed recovery of the thresholds. FMEPs in patients who underwent the infrafacial triangle approach were stable during the surgery. House-Brackmann grades were unchanged postoperatively in all patients. Postoperative KPS scores improved in 3 patients, decreased in 1, and remained the same in 6 patients.CONCLUSIONSFMEPs can be used to monitor facial nerve function during surgery for pontine cavernous malformations, especially when the suprafacial triangle approach is performed.

Optimal access route for pontine cavernous malformation resection with preservation of abducens and facial nerve function

2020 ◽  
pp. 1-10
Author(s):  
Helmut Bertalanffy ◽  
Shinya Ichimura ◽  
Souvik Kar ◽  
Yoshihito Tsuji ◽  
Caiquan Huang
Keyword(s):  
Facial Nerve ◽  
Retrospective Analysis ◽  
Scale Score ◽  
Surgical Approach ◽  
Posterolateral Approach ◽  
Nerve Function ◽  
Modified Rankin Scale ◽  
Access Route ◽  
Facial Nerve Function ◽  
Patient Groups

OBJECTIVEThe aim of this study was to analyze the differences between posterolateral and posteromedial approaches to pontine cavernous malformations (PCMs) in order to verify the hypothesis that a posterolateral approach is more favorable with regard to preservation of abducens and facial nerve function.METHODSThe authors conducted a retrospective analysis of 135 consecutive patients who underwent microsurgical resection of a PCM. The vascular lesions were first classified in a blinded fashion into 4 categories according to the possible or only reasonable surgical access route. In a second step, the lesions were assessed according to which approach was performed and different patient groups and subgroups were determined. In a third step, the modified Rankin Scale score and the rates of permanent postoperative abducens and facial nerve palsies were assessed.RESULTSThe largest group in this series comprised 77 patients. Their pontine lesion was eligible for resection from either a posterolateral or posteromedial approach, in contrast to the remaining 3 patient groups in which the lesion location already had dictated a specific surgical approach. Fifty-four of these 77 individuals underwent surgery via a posterolateral approach and 23 via a posteromedial approach. When comparing these 2 patient subgroups, there was a statistically significant difference between postoperative rates of permanent abducens (3.7% vs 21.7%) and facial (1.9% vs 21.7%) nerve palsies. In the entire patient population, the abducens and facial nerve deficit rates were 5.9% and 5.2%, respectively, and the modified Rankin Scale score significantly decreased from 1.6 ± 1.1 preoperatively to 1.0 ± 1.1 at follow-up.CONCLUSIONSThe authors’ results suggest favoring a posterolateral over a posteromedial access route to PCMs in patients in whom a lesion is encountered that can be removed via either surgical approach. In the present series, the authors have found such a constellation in 57% of all patients. This retrospective analysis confirms their hypothesis in a large patient cohort. Additionally, the authors demonstrated that 4 types of PCMs can be distinguished by preoperatively evaluating whether only one reasonable or two alternative surgical approaches are available to access a specific lesion. The rates of postoperative sixth and seventh nerve palsies in this series are substantially lower than those in the majority of other published reports.

scholarly journals Grading Facial Nerve Function Following Combined Static and Mimetic Surgical Techniques

2015 ◽  
Vol 76 (06) ◽  
pp. 416-420
Author(s):  
Sam Marzo ◽  
Douglas Anderson ◽  
Joshua Sappington ◽  
John Leonetti
Keyword(s):  
Facial Nerve ◽  
Surgical Techniques ◽  
Nerve Function ◽  
Facial Nerve Function

Facial Nerve Dissection by use of Acoustic (Loudspeaker) Facial EMG Monitoring

1986 ◽  
Vol 95 (4) ◽  
pp. 458-463 ◽  
Author(s):  
Sam E. Kinney ◽  
Richard Prass
Keyword(s):  
Facial Nerve ◽  
Acoustic Neuroma ◽  
Internal Auditory Canal ◽  
Subsequent Development ◽  
Lateral Approach ◽  
Nerve Function ◽  
Facial Nerve Function ◽  
Facial Emg ◽  
Acoustic Neuroma Surgery ◽  
Total Tumor Removal

The development of the surgical microscope in 1953, and the subsequent development of microsurgical instrumentation, signaled the beginning of modern-day acoustic neuroma surgery. Preservation of facial nerve function and total tumor removal is the goal of all acoustic neuroma surgery. The refinement of the translabyrinthine removal of acoustic neuromas by Dr. William House’ significantly improved preservation of facial nerve function. This is made possible by the anatomic identification of the facial nerve at the lateral end of the internal auditory canal. When the surgery is accomplished from a suboccipital or retrosigmoid approach, the facial nerve may be identified at the brain stem or within the internal auditory canal. Identifying the facial nerve from the posterior approach is not as anatomically precise as from the lateral approach through the labyrinth. The use of a facial nerve stimulator can greatly facilitate Identification of the facial nerve in these procedures.

scholarly journals The Offprint of an Abnormal Pre-Parotidectomy Electrodiagnostic Finding in a Normally Functioning Facial Nerve: Correlation with Intraoperative Findings, Histology and Postoperative Facial Nerve Function

2022 ◽  
Vol 11 (1) ◽  
pp. 248
Author(s):  
Verena Katheder ◽  
Matti Sievert ◽  
Sarina Katrin Müller ◽  
Vivian Thimsen ◽  
Antoniu-Oreste Gostian ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Malignant Tumor ◽  
Facial Palsy ◽  
Benign Lesion ◽  
Nerve Function ◽  
Facial Nerve Function ◽  
Nerve Preservation ◽  
Clinically Normal ◽  
Parotid Tumors ◽  
Supramaximal Stimulation

The aim of this study was to search for associations between an electrodiagnostically abnormal but clinically normal facial nerve before parotidectomy and the intraoperative findings, as well as the postoperative facial nerve function. The records of all patients treated for parotid tumors between 2002 and 2021 with a preoperative House–Brackmann score of grade I but an abnormal electrophysiologic finding were studied retrospectively. A total of 285 patients were included in this study, and 222 patients had a benign lesion (77.9%), whereas 63 cases had a malignant tumor (22.1%). Electroneurographic facial nerve involvement was associated with nerve displacement in 185 cases (64.9%) and infiltration in 17 cases (6%). In 83 cases (29.1%), no tumor–nerve interface could be detected intraoperatively. An electroneurographic signal was absent despite supramaximal stimulation in 6/17 cases with nerve infiltration and in 17/268 cases without nerve infiltration (p < 0.001). The electrophysiologic involvement of a normal facial nerve is not pathognomonic for a malignancy (22%), but it presents a rather rare (~6%) sign of a “true” nerve infiltration and could also appear in tumors without any contact with the facial nerve (~29%). Of our cases, two thirds of those with an anatomic nerve preservation and facial palsy had already directly and postoperatively recovered to a major extent in the midterm.

scholarly journals Preservation of Hearing and Facial Nerve Function with the Microsurgical Excision of Large Vestibular Schwannomas: Experience with the Retrosigmoid Approach

Cureus ◽  
2018 ◽  
Author(s):  
Muhammad Shaheryar Ahmed Rajput ◽  
Ahmad Nawaz Ahmad ◽  
Asif Ali Arain ◽  
Mohammad Adeel ◽  
Saeed Akram ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Retrosigmoid Approach ◽  
Vestibular Schwannomas ◽  
Nerve Function ◽  
Facial Nerve Function
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