A step backward: The ‘Rough’ facial nerve grading system

Beyond the smile: a systematic review of diagnostic tools for peripheral facial paralysis

BACKGROUND

Effective rehabilitation of peripheral facial paralysis (PFP) requires reliable assessment tools. This systematic review aimed to identify and validate instruments used in PFP rehabilitation, categorizing them according to the ICF framework.

METHODS

A comprehensive search was conducted across PubMed, Cinahl, Web of Science, and Scopus up to April 2024. Observational analytical studies and one non-randomized controlled trial that validated tools for assessing PFP were included.

RESULTS

Thirty-three studies were included, covering twenty different tools. Seventeen tools were related to the "Structure and Function" domain, while three addressed "Activity and Participation." The Sunnybrook and House-Brackmann scales were the most extensively studied. The Sunnybrook scale exhibited excellent intra- and inter-rater reproducibility and internal validity, making it suitable for clinical use. The House-Brackmann scale was user-friendly but had limitations in reproducibility and sensitivity to subtle differences, which newer versions like the FNGS 2.0 aimed to address. The FAME scale showed promise by reducing subjective scoring. Computerized tools, such as eFACE and A-FPG, and instruments for lip asymmetry and ocular involvement demonstrated potential but require further validation. The Facial Disability Index and the FaCE Scale were validated for assessing disability and participation restrictions.

CONCLUSION

This review identified several validated tools for PFP assessment, with the Sunnybrook and House-Brackmann scales being the most reliable. While emerging tools and computerized programs show promise, they need further validation for routine clinical use. Integrating validated tools into clinical practice is essential for comprehensive assessment and effective rehabilitation of PFP.

Evidence-Based Practices in Facial Reanimation Surgery

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Describe the causes and preoperative evaluation of facial paralysis. 2. Discuss techniques to restore corneal sensation and eyelid closure, elevation of the upper lip for smile, and depression of the lower lip for lip symmetry. 3. Outline treatment goals, surgical treatment options, timing of repair, and other patient-specific considerations in appropriate technique selection.

SUMMARY

Congenital facial paralysis affects 2.7 per 100,000 children; Bell palsy affects 23 per 100,000 people annually; and even more people are affected when considering all other causes. Conditions that impair facial mimetics impact patients' social functioning and emotional well-being. Dynamic and static reconstructive methods may be used individually or in concert to achieve adequate blink restoration, smile strength and spontaneity, and lower lip depression. Timing of injury and repair, patient characteristics such as age, and cause of facial paralysis are all considered in selecting the most appropriate reconstructive approach. This article describes evidence-based management of facial paralysis.

Neural networks for estimation of facial palsy after vestibular schwannoma surgery

PURPOSE

Facial nerve damage in vestibular schwannoma surgery is associated with A-train patterns in free-running EMG, correlating with the degree of postoperative facial palsy. However, anatomy, preoperative functional status, tumor size and occurrence of A-trains clusters, i.e., sudden A-trains in most channels may further contribute. In the presented study, we examine neural networks to estimate postoperative facial function based on such features.

METHODS

Data from 200 consecutive patients were used to train neural feed-forward networks (NN). Estimated and clinical postoperative House and Brackmann (HB) grades were compared. Different input sets were evaluated.

RESULTS

Networks based on traintime, preoperative HB grade and tumor size achieved good estimation of postoperative HB grades (chi2 = 54.8), compared to using tumor size or mean traintime alone (chi2 = 30.6 and 31.9). Separate intermediate nerve or detection of A-train clusters did not improve performance. Removal of A-train cluster traintime improved results (chi2 = 54.8 vs. 51.3) in patients without separate intermediate nerve.

CONCLUSION

NN based on preoperative HB, traintime and tumor size provide good estimations of postoperative HB. The method is amenable to real-time implementation and supports integration of information from different sources. NN could enable multimodal facial nerve monitoring and improve postoperative outcomes.

Assessing Adult Patients with Facial Deformities for Injectable Treatment: Do Current Classification Systems and Methodologies Meet Important Patient Needs?

BACKGROUND

Many individuals are affected by facial deformities. Injectable aesthetic treatments can often be used to improve appearance and/or dynamic function. However, to best meet the needs of these patients, broadly applicable methodologies are required for classifying the deformity, assessing severity, and developing a treatment strategy.

OBJECTIVE

To assess whether any published systems could be used for this purpose.

METHODS

Thirty-eight searches were conducted in PubMed (1999-2019; in English). Forty-two publications were identified describing novel classification systems for adult facial deformity. They were analyzed against a checklist of 10 characteristics defining an "optimal" system-based on appropriate anatomical coverage, wide usability across types of deformity, user-friendliness, applicable underlying methodology, and ability to guide treatment with injectables.

RESULTS

None of the systems met more than 7 of the 10 checklist criteria; none were usable across multiple types of deformity or provided a recommendation for treatment with injectables.

CONCLUSION

There remains a need for a broadly applicable system for classifying adult facial deformities ahead of injectable therapy. The checklist provides a developmental framework. With the increasing popularity and accessibility of injectables, this diverse and complex demographic is at risk of mismanagement without superior methods for devising treatment strategies.

Advanced Statistical Analysis of 3D Kinect Data: Mimetic Muscle Rehabilitation Following Head and Neck Surgeries Causing Facial Paresis

An advanced statistical analysis of patients’ faces after specific surgical procedures that temporarily negatively affect the patient’s mimetic muscles is presented. For effective planning of rehabilitation, which typically lasts several months, it is crucial to correctly evaluate the improvement of the mimetic muscle function. The current way of describing the development of rehabilitation depends on the subjective opinion and expertise of the clinician and is not very precise concerning when the most common classification (House–Brackmann scale) is used. Our system is based on a stereovision Kinect camera and an advanced mathematical approach that objectively quantifies the mimetic muscle function independently of the clinician’s opinion. To effectively deal with the complexity of the 3D camera input data and uncertainty of the evaluation process, we designed a three-stage data-analytic procedure combining the calculation of indicators determined by clinicians with advanced statistical methods including functional data analysis and ordinal (multiple) logistic regression. We worked with a dataset of 93 distinct patients and 122 sets of measurements. In comparison to the classification with the House–Brackmann scale the developed system is able to automatically monitor reinnervation of mimetic muscles giving us opportunity to discriminate even small improvements during the course of rehabilitation.

Exploring Patient Experience of Facial Nerve Palsy to Inform the Development of a PROM

BACKGROUND

There is currently a mandate globally to incorporate patient's perceptions of their illness into outcome measures, in order to provide a deeper insight into medical practice. Facial nerve palsy (FNP) is a devastating condition that can significantly impact quality of life. However, no measure currently exists that comprehensively assesses outcome in FNP using patient perception. The aim of this study is to explore patients' experiences of FNP with the aim of informing the development of a patient-reported outcome measure.

METHODS

Presented is a qualitative study, using in-depth semi-structured interviews with FNP patients. An interview guide was developed using expert opinion and a literature review. Interpretative description was used as the qualitative approach. Interviews were audio-recorded, transcribed, and coded line-by-line. Codes were refined using the constant comparison approach. Interviews continued until data saturation was reached. The data were used to develop a conceptual framework of patient perceived issues relating to FNP.

RESULTS

The sample included 5 men and 9 women aged 57.7 years (range, 36-78) with a range of causes of FNP, including Bell's palsy (n = 5), acoustic neuroma (n = 3), trauma (n = 2), meningioma (n = 1), muscular dystrophy (n = 1), congenital (n = 1), and Ramsay Hunt syndrome (n = 1). Analysis of the 14 participant interviews led to identification of 5 major domains including "facial function concerns," "appearance concerns," "psychological function," "social function," and "experience of care."

CONCLUSION

This study provides a conceptual framework covering outcomes that matter to patients with FNP, which can be used to inform the development of a new comprehensive FNP-specific patient-reported outcome measure.

An Unobtrusive Computerized Assessment Framework for Unilateral Peripheral Facial Paralysis

Unilateral peripheral facial paralysis (UPFP) is a form of facial nerve paralysis and clinically classified according to conditions of facial symmetry. Prompt and precise assessment is crucial to neural rehabilitation of UPFP. The prevalent House-Brackmann (HB) grading system relies on subjective judgments with significant interobservation variation. Therefore, to explore an objective method for the UPFP assessment, clinical image sequences are captured using a web camera setup while 5 healthy and 27 UPFP subjects perform a group of predefined actions, including keeping expressionless, raising brows, closing eyes, bulging cheek, and showing teeth in turn. First, facial region is decided using Haar cascade classifier, and then landmark points are acquired by a supervised descent method. Second, these landmark points are used to generate a group of features reflecting the structural parameters of regions of eyebrows, eyes, nose, and mouth, respectively. Third, correlation coefficients are computed between the raw features HB scores. To reduce feature dimensions, only those with correlation coefficients larger than an empirically selected value, 0.35, are input into a support vector machine to generate a classifier. With the classifier, exact match (discrepancy = 0 between result from proposed method and HB scores) rate at 49.9%, and loose match (discrepancy = 1) rate at 87.97% are achieved on the experiment data. After sample augmentation, the final rate is increased to 90.01%, outperformed previous reports. In conclusion, it is demonstrated with an unobtrusive web camera setup, encouraging results have been generated with the proposed framework in this exploratory study.

Interobserver variability of the House-Brackmann facial nerve grading system for the analysis of a randomized multi-center phase III trial

BACKGROUND

Evidence of a high interobserver variability of the subjective House-Brackmann facial nerve grading system (HBGS) would justify cost- and time-consuming technological enhancements of objective classifications for facial nerve paresis.

METHOD

A total of 112 patients were recruited for a randomized multi-center trial to investigate the efficacy of prophylactic nimodipine treatment in vestibular schwannoma (VS) surgery. For the present investigation both treatment groups were pooled for the assessment of facial nerve function preoperatively, in the early postoperative course and 1 year after the surgery. Facial nerve function was documented photographically at rest and in motion and classified according to the HBGS by three independent observers (neurosurgeon, neurologist, ENT) and by the investigator of each center.

RESULTS

Interobserver variability was considerably different with respect to the three time points depending upon the severity of facial nerve paresis. Preoperative facial nerve function was normal or only mildly impaired (HB grade I or II) and was assessed consistently in 97%. Facial nerve function deteriorated during the early postoperative course and was subsequently documented without dissent in only 36%, with one grade difference in 45%, two grade difference in 17% and three grade difference in 2%. One year after surgery, facial nerve function predominantly improved resulting in a consistent assessment in 66%. Differing ratings were observed in 34% with one grade deviation in 88% and of two grades in 12%. Patients with differing ratings of two or more grades exhibited considerably worse facial nerve function (p < 0.001).

CONCLUSIONS

The HBGS produced comparable results between different observers in patients with normal or only mildly impaired facial nerve function. Interobserver variability increased depending on the severity of facial nerve paresis. The results suggest that the HBGS does not promote uniformity of reporting and comparison of outcomes in patients with moderate or severe facial nerve paresis.

Exclusive endoscopic transcanal transpromontorial approach: a new perspective for internal auditory canal vestibular schwannoma treatment

OBJECTIVE

The aim of this study was to describe the first case series in which an exclusive endoscopic transcanal transpromontorial approach (EETTA) was used to treat small vestibular schwannomas (VSs) and meningiomas of the internal auditory canal (IAC).

METHODS

The authors performed a retrospective review of patients who had undergone surgery using an EETTA to the IAC at 2 university tertiary care referral centers during the period from November 2011 to January 2015.

RESULTS

Ten patients underwent surgery via an EETTA for the treatment of VS in the IAC at the University Hospital of Modena or the University Hospital of Verona. The patients had Koos Grade I or II tumors and American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS) Class D hearing status preoperatively. Gross-total resection was achieved in all patients. No major complications such as cerebrospinal fluid leakage or hemorrhage were reported. In 7 of 10 (70%) patients, facial nerve function was normal immediately after surgery (Rough Grading System [RGS] Grade I). Two patients presented with a transitory facial palsy immediately after surgery (RGS Grade II–III) but experienced complete recovery during the follow-up period. The mean follow-up was 10 months.

CONCLUSIONS

The EETTA proved to be successful for the removal of VS or meningioma involving the cochlea, fundus, and IAC, with possible lower complication rates and less invasive procedures than those for traditional microscopic approaches. The potential for the extensive and routine use of this approach in lateral and posterior skull base surgery will depend on the development of technology and surgical refinements and on the diffusion of skull base endoscopic skills among the otolaryngological and neurosurgical communities.

Facial nerve grading instruments: systematic review of the literature and suggestion for uniformity

BACKGROUND

A variety of facial nerve grading scales have been developed over the years with the intended goals of objectively documenting facial nerve function,tracking recovery, and facilitating communication between practitioners. Numerous scales have been proposed; however, all are subject to limitation because of varying degrees of subjectivity, reliability, or longitudinal applicability. At present, such scales remain the only widely accessible modalities for facial functional assessment. The authors' objective was to ascertain which scales(s) best accomplish the goals of objective assessment.

METHODS

A systematic review of the English language literature was performed to identify facial nerve grading instruments. Each system was evaluated against the following criteria: convenience of clinical use, regional scoring, static and dynamic measures, features secondary to facial palsy (e.g., synkinesis), reproducibility with low interobserver and intraobserver variability, and sensitivity to changes over time and/or following interventions.

RESULTS

From 666 articles, 19 facial nerve grading scales were identified. Only the Sunnybrook Facial Grading Scale satisfied all criteria. The Facial Nerve Grading Scale 2.0 (or revised House-Brackmann Scale) fulfilled all criteria except intraobserver reliability, which has not been assessed.

CONCLUSIONS

Facial nerve grading scales intend to provide objectivity and uniformity of reporting to otherwise subjective analysis. The Facial Nerve Grading Scale 2.0 requires further evaluation for intraobserver reliability. The Sunnybrook Facial Grading Scale has been robustly evaluated with respect to the criteria prescribed in this article. Although sophisticated technology-based methodologies are being developed for potential clinical application,the authors recommend widespread adoption of the Sunnybrook Facial Grading Scale as the current standard in reporting outcomes of facial nerve disorders.

Endoscopic transcanal corridors to the lateral skull base: Initial experiences

OBJECTIVES/HYPOTHESIS

Surgical approaches to the lateral skull base, internal auditory canal (IAC), and petrous bone are widely known and have been extensively recorded. Despite the benign nature and limited dimensions of lesions located in this anatomical region, extirpative surgical approaches are often required to reach and remove the disease. The aim of present report was to describe our initial experiences with minimally invasive endoscopic approaches to the lateral skull base.

STUDY DESIGN

Retrospective review of patients' charts and video recordings from surgery.

METHODS

Twelve patients were included in the study. Three main corridors to the lateral skull base were identified: the transcanal suprageniculate corridor, the transcanal transpromontorial corridor, and the transcanal infracochlear corridor. Landmarks, tips, and pitfalls of the approaches have been reviewed and highlighted.

RESULTS

These corridors provide a direct approach to pathology involving the fundus, IAC, cochlea, petrous apex and geniculate ganglion region, without any external incision. The pathology was successfully removed in most cases with no important postoperative complications and reasonable facial nerve outcomes.

CONCLUSIONS

The transcanal endoscopic approaches to the lateral skull base proved to be successful for pathology removal involving the fundus, IAC, cochlea, petrous apex, and geniculate ganglion region. Future widespread application of this kind of approach in lateral skull base surgery will depend on the development of technology, and surgical and anatomical refinements.

LEVEL OF EVIDENCE

4.