Automated objective and marker-free facial grading using photographs of patients with facial palsy

Automated analysis of spontaneous eye blinking in patients with acute facial palsy or facial synkinesis

Although patients with facial palsy often complain of disturbed eye blinking which may lead to visual impairment, a blinking analysis is not part of routine grading of facial palsy. Twenty minutes of spontaneous eye blinking at rest of 30 patients with facial palsy (6 with acute palsy; 24 patients with facial synkinesis; median age: 58 years, 67% female), and 30 matched healthy probands (median age: 57 years; 67% female) was smart phone video recorded. A custom computer program automatically extracted eye measures and determined the eye closure rate (eye aspect ratio [EAR]), blink frequency, and blink duration. Facial Clinimetric Evaluation (FaCE), Facial Disability Index (FDI) were assessed as patient-reported outcome measures. The minimal EAR, i.e., minimal visible eye surface during blinking, was significantly higher on the paretic side in patients with acute facial palsy than in patients with synkinesis or in healthy controls. The blinking frequency on the affected side was significantly lower in both patient groups compared to healthy controls. Vice versa, blink duration was longer in both patient groups. There was no clear correlation between the blinking values and FaCE and FDI. Blinking parameters are easy to estimate automatically and add a functionally important parameter to facial grading.

Diagnosing lagophthalmos using artificial intelligence

Lagophthalmos is the incomplete closure of the eyelids posing the risk of corneal ulceration and blindness. Lagophthalmos is a common symptom of various pathologies. We aimed to program a convolutional neural network to automatize lagophthalmos diagnosis. From June 2019 to May 2021, prospective data acquisition was performed on 30 patients seen at the Department of Plastic, Hand, and Reconstructive Surgery at the University Hospital Regensburg, Germany (IRB reference number: 20-2081-101). In addition, comparative data were gathered from 10 healthy patients as the control group. The training set comprised 826 images, while the validation and testing sets consisted of 91 patient images each. Validation accuracy was 97.8% over the span of 64 epochs. The model was trained for 17.3 min. For training and validation, an average loss of 0.304 and 0.358 and a final loss of 0.276 and 0.157 were noted. The testing accuracy was observed to be 93.41% with a loss of 0.221. This study proposes a novel application for rapid and reliable lagophthalmos diagnosis. Our CNN-based approach combines effective anti-overfitting strategies, short training times, and high accuracy levels. Ultimately, this tool carries high translational potential to facilitate the physician's workflow and improve overall lagophthalmos patient care.

The Emerging Role of Artificial Intelligence Tools for Outcome Measurement in Facial Reanimation Surgery: A Review

Importance: Surgeons treating facial paralysis with reanimation surgery measure the outcomes of surgery and adjust treatment to each patient's needs. Our objective is to review the current subjective facial paralysis assessment tools and the emerging computer-based objective analysis, which may involve artificial intelligence. Observations: In recent years, many new automated approaches to outcome measurement in facial reanimation surgery have been developed. Most of these tools utilize artificial intelligence to analyze emotional expression and symmetry of facial landmarks. Other tools have provided automated approaches to existing clinician-guided scales. Conclusions: Newly developed computer-based tools using artificial intelligence have been developed to both improve existing clinician-graded scales and provide new approaches to facial symmetry and emotional expressivity analysis.

Assessing facial weakness in myasthenia gravis with facial recognition software and deep learning

OBJECTIVE

Myasthenia gravis (MG) is an autoimmune disease leading to fatigable muscle weakness. Extra-ocular and bulbar muscles are most commonly affected. We aimed to investigate whether facial weakness can be quantified automatically and used for diagnosis and disease monitoring.

METHODS

In this cross-sectional study, we analyzed video recordings of 70 MG patients and 69 healthy controls (HC) with two different methods. Facial weakness was first quantified with facial expression recognition software. Subsequently, a deep learning (DL) computer model was trained for the classification of diagnosis and disease severity using multiple cross-validations on videos of 50 patients and 50 controls. Results were validated using unseen videos of 20 MG patients and 19 HC.

RESULTS

Expression of anger (p = 0.026), fear (p = 0.003), and happiness (p < 0.001) was significantly decreased in MG compared to HC. Specific patterns of decreased facial movement were detectable in each emotion. Results of the DL model for diagnosis were as follows: area under the curve (AUC) of the receiver operator curve 0.75 (95% CI 0.65-0.85), sensitivity 0.76, specificity 0.76, and accuracy 76%. For disease severity: AUC 0.75 (95% CI 0.60-0.90), sensitivity 0.93, specificity 0.63, and accuracy 80%. Results of validation, diagnosis: AUC 0.82 (95% CI: 0.67-0.97), sensitivity 1.0, specificity 0.74, and accuracy 87%. For disease severity: AUC 0.88 (95% CI: 0.67-1.0), sensitivity 1.0, specificity 0.86, and accuracy 94%.

INTERPRETATION

Patterns of facial weakness can be detected with facial recognition software. Second, this study delivers a 'proof of concept' for a DL model that can distinguish MG from HC and classifies disease severity.

Automatic grading of patients with a unilateral facial paralysis based on the Sunnybrook Facial Grading System - A deep learning study based on a convolutional neural network

PURPOSE

In order to assess the severity and the progression of a unilateral peripheral facial palsy the Sunnybrook Facial Grading System (SFGS) is a well-established grading system due to its clinical relevance, sensitivity, and robust measuring method. However, training is required in order to achieve a high inter-rater reliability. This study investigated the automated grading of facial palsy patients based on the SFGS using a convolutional neural network.

METHODS

A total of 116 patients with a unilateral peripheral facial palsy and 9 healthy subjects were recorded performing the Sunnybrook poses. A separate model was trained for each of the 13 elements of the SFGS and then used to calculate the Sunnybrook subscores and composite score. The performance of the automated grading system was compared to three clinicians experienced in the grading of a facial palsy.

RESULTS

The inter-rater reliability of the convolutional neural network was within the range of human observers, with an average intra-class correlation coefficient of 0.87 for the composite Sunnybrook score, 0.45 for the resting symmetry subscore, 0.89 for the symmetry of voluntary movement subscore, and 0.77 for the synkinesis subscore.

CONCLUSIONS

This study showed the potential of the automated SFGS to be implemented in a clinical setting. The automated grading system adhered to the original SFGS, which makes the implementation and interpretation of the automated grading more straightforward. The automated system can be implemented in numerous settings such as online consults in an e-Health environment, since the model used 2D images captured from a video recording.

The Feasibility of An Automatical Facial Evaluation System Providing Objective and Reliable Results for Facial Palsy

Facial palsy would lead to a series of physical and mental problems, as facial function plays an important role in various aspects of daily life. However, the current strategies for evaluating facial function relied heavily on raters and the results varied from the experience of raters. Thus, an objective and accurate facial evaluation system is always claimed. In this study, a customized automatical facial evaluation system (AFES) was proposed, which might have the potential to be employed as an adjunctive and efficient assessing method in clinic. In order to investigate the feasibility of AFES, ninety-two participants with facial palsy were recruited and received scale-based subjective manual evaluation (including mHBGS and mSFGS) and objective automatical evaluation of AFES (including aHBGS, aSFGS and indicators of facial regional features) at enrollment and after two weeks. The correlations between the results of the two methods were analyzed and the participants were stratified according to the severity of facial function for further analyses. Strong positive correlations between manual and automatical HBGS and SFGS were observed and higher correlations were reported in the participants with normal-mild and moderate facial palsy. Significant improvements in clinical scales and indicator of eye synkinesis were found in forty-two participants in two weeks. Furthermore, some of the indicators were correlated with scale scores (I4, I7) and one of them presented a significant change between the baseline evaluation and follow-up evaluation (I7). According to the results, AFES could be considered as a viable method to perform objective and reliable evaluation for patients with facial palsy and provide clarified results for prognosis.

A Ready-to-Use Grading Tool for Facial Palsy Examiners—Automated Grading System in Facial Palsy Patients Made Easy

Background: The grading process in facial palsy (FP) patients is crucial for time- and cost-effective therapy decision-making. The House-Brackmann scale (HBS) represents the most commonly used classification system in FP diagnostics. This study investigated the benefits of linking machine learning (ML) techniques with the HBS. Methods: Image datasets of 51 patients seen at the Department of Plastic, Hand, and Reconstructive Surgery at the University Hospital Regensburg, Germany, between June 2020 and May 2021, were used to build the neural network. A total of nine facial poses per patient were used to automatically determine the HBS. Results: The algorithm had an accuracy of 98%. The algorithm processed the real patient image series (i.e., nine images per patient) in 112 ms. For optimized accuracy, we found 30 training runs to be the most effective training length. Conclusion: We have developed an easy-to-use, time- and cost-efficient algorithm that provides highly accurate automated grading of FP patient images. In combination with our application, the algorithm may facilitate the FP surgeon’s clinical workflow.

Towards a Reliable and Rapid Automated Grading System in Facial Palsy Patients: Facial Palsy Surgery Meets Computer Science

Background: Reliable, time- and cost-effective, and clinician-friendly diagnostic tools are cornerstones in facial palsy (FP) patient management. Different automated FP grading systems have been developed but revealed persisting downsides such as insufficient accuracy and cost-intensive hardware. We aimed to overcome these barriers and programmed an automated grading system for FP patients utilizing the House and Brackmann scale (HBS). Methods: Image datasets of 86 patients seen at the Department of Plastic, Hand, and Reconstructive Surgery at the University Hospital Regensburg, Germany, between June 2017 and May 2021, were used to train the neural network and evaluate its accuracy. Nine facial poses per patient were analyzed by the algorithm. Results: The algorithm showed an accuracy of 100%. Oversampling did not result in altered outcomes, while the direct form displayed superior accuracy levels when compared to the modular classification form (n = 86; 100% vs. 99%). The Early Fusion technique was linked to improved accuracy outcomes in comparison to the Late Fusion and sequential method (n = 86; 100% vs. 96% vs. 97%). Conclusions: Our automated FP grading system combines high-level accuracy with cost- and time-effectiveness. Our algorithm may accelerate the grading process in FP patients and facilitate the FP surgeon’s workflow.

Facial Emotion Recognition in Patients with Post-Paralytic Facial Synkinesis—A Present Competence

Facial palsy is a movement disorder with impacts on verbal and nonverbal communication. The aim of this study is to investigate the effects of post-paralytic facial synkinesis on facial emotion recognition. In a prospective cross-sectional study, we compared facial emotion recognition between n = 30 patients with post-paralytic facial synkinesis (mean disease time: 1581 ± 1237 days) and n = 30 healthy controls matched in sex, age, and education level. Facial emotion recognition was measured by the Myfacetraining Program. As an intra-individual control condition, auditory emotion recognition was assessed via Montreal Affective Voices. Moreover, self-assessed emotion recognition was studied with questionnaires. In facial as well as auditory emotion recognition, on average, there was no significant difference between patients and healthy controls. The outcomes of the measurements as well as the self-reports were comparable between patients and healthy controls. In contrast to previous studies in patients with peripheral and central facial palsy, these results indicate unimpaired ability for facial emotion recognition. Only in single patients with pronounced facial asymmetry and severe facial synkinesis was an impaired facial and auditory emotion recognition detected. Further studies should compare emotion recognition in patients with pronounced facial asymmetry in acute and chronic peripheral paralysis and central and peripheral facial palsy.

[Preservation, reconstruction, and rehabilitation of the facial nerve]

Der Umgang mit dem N. facialis ist bei der Operation eines Parotiskarzinoms wichtig für die Langzeitlebensqualität des Patienten. In etwa 2 Drittel der Fälle ist der N. facialis nicht vom Tumor befallen. In diesen Fällen sind neben vollständiger Tumorentfernung die Identifizierung und der Erhalt des Nervs für eine erfolgreiche Operation wesentlich. Ist der Nerv vom Tumor infiltriert, muss der betroffene Teil des Nervs im Rahmen einer radikalen Parotidektomie reseziert werden. Die primäre Nervenrekonstruktion, sofern möglich, führt zu den besten funktionellen und kosmetischen Langzeitergebnissen. Das individuell optimale Therapiekonzept basiert zum einen auf der klinischen Prüfung der Gesichtsbeweglichkeit, zum anderen auf der präoperativen Bildgebung, um die Lagebeziehung zwischen Tumor und Nerv zu verstehen, und schließlich auf einer elektrophysiologischen Untersuchung zur Funktion des Nervs. Intraoperativ hilft ein standardisiertes Vorgehen, um den Nerv zu identifizieren und zu erhalten. Wenn eine radikale Parotidektomie indiziert ist, kann bereits die präoperative Diagnostik helfen, neben der einzeitigen Rekonstruktion auch die adjuvante postoperative Therapie zu planen. Das Ziel der Rehabilitation ist die Wiederherstellung von Tonus, Symmetrie und Bewegung des gelähmten Gesichts. Die Wiederherstellung des Augenschlusses hat hohe Priorität. Bei der chirurgischen Therapie von Gesichtslähmungen gab es in den letzten Jahren viele Verbesserungen. Die vorliegende Arbeit gibt einen Überblick über die jüngsten Fortschritte in der Diagnostik, den Operationstechniken und weiteren Möglichkeiten zur Protektion des gesunden N. facialis. Anderseits wird die Rehabilitation des tumorinfiltrierten N. facialis im Kontext der Behandlung von Speicheldrüsenmalignomen beschrieben.

Multidisciplinary Care of Patients with Facial Palsy: Treatment of 1220 Patients in a German Facial Nerve Center

To determine treatment and outcome in a tertiary multidisciplinary facial nerve center, a retrospective observational study was performed of all patients referred between 2007 and 2018. Facial grading with the Stennert index, the Facial Clinimetric Evaluation (FaCE) scale, and the Facial Disability Index (FDI) were used for outcome evaluation; 1220 patients (58.4% female, median age: 50 years; chronic palsy: 42.8%) were included. Patients with acute and chronic facial palsy were treated in the center for a median of 3.6 months and 10.8 months, respectively. Dominant treatment in the acute phase was glucocorticoids ± acyclovir (47.2%), followed by a significant improvement of all outcome measures (p < 0.001). Facial EMG biofeedback training (21.3%) and botulinum toxin injections (11%) dominated the treatment in the chronic phase, all leading to highly significant improvements according to facial grading, FDI, and FaCE (p < 0.001). Upper eyelid weight (3.8%) and hypoglossal–facial-nerve jump suture (2.5%) were the leading surgical methods, followed by improvement of facial motor function (p < 0.001) and facial-specific quality of life (FDI, FaCE; p < 0.05). A standardized multidisciplinary team approach in a facial nerve center leads to improved facial and emotional function in patients with acute or chronic facial palsy.

Supercharged massetric-facial cross-graft for gracilis reinnervation in unilateral facial palsy treatment

BACKGROUND

The choice of neurotization source for gracilis neuromuscular transplant is a key point in the treatment of unilateral long-standing paralysis. To combine the advantages of different donor nerves and overcome their disadvantages, mixed neurotization sources have been described with encouraging results. The authors present a preliminary report of a novel technique, the "supercharged" cross-graft, a two-step technique consisting of a double powered cross nerve graft provided by a zygomatic branch of the healthy facial nerve and the masseter nerve of the healthy side.

PATIENTS AND METHODS

From January 2015 to December 2019 eight patients, aged between 19 and 61 years old (mean age at surgery 33.62) suffering unilateral established paralysis (congenital or acquired, >24 months) underwent gracilis reinnervation with the supercharged cross grafting technique. Subjects underwent a two-step surgical rehabilitation: in the first operation sural nerve was harvested and used as cross-graft cooptated by healthy side facial nerve branch and masseteric nerve. During second procedure gracilis neuromuscular transplant was performed reinnervarting the muscle with the cross-graft. Patients were evaluated using Emotrics software, which allowed for automated facial measurements on post-operative pictures taken at the last follow-up. The results of the different poses were compared to assess the contribution to smile excursion by the masseter and facial nerve, together and separately. Finally, we analyzed spontaneous smile to assess whether masseteric contribution is used in daily life.

RESULTS

No major or minor complications occurred. Follow-up time ranged from 12 to 41 months, with a mean of 22.75 months. A good commissure excursion (mean 33.84 mm) was obtained during smile with no teeth clenching (without masseter activation), as well as during teeth clenching without smiling (activation of gracilis only - mean 32.55). When smiling and biting simultaneously the excursion was greater than the single two components (mean 35.91). In spontaneous smile, commissure excursion was higher (mean 34.23) than that provided by only the facial nerve (smile only) in most patients.

CONCLUSIONS

This novel technique of mixed neurotization for gracilis transplant shows consistent results with powerful contraction and good smile coordination. It also allows us to extend the indications for mixed neurotization techniques.

[Diagnostics and Therapy of Idiopathic Facial Palsy (Bell's Palsy)]

The purpose of this review is to report the knowledge for otolaryngologists on standard of care, latest advances, interesting new findings and controversies about the treatment of Bell's palsy. This review is focusing on the acute phase of the disease. The chronic phase, with incomplete, incorrect or no recovery of the palsy, is described briefly. Treatment with prednisolone alone within 72 hours after onset still is the cornerstone of the treatment. The role of antivirals still is unclear. Since 2009 no new and breakthrough clinical trials with influence on the treatment standards have been performed. A study to clarify the role of prednisolone treatment in children is ongoing. Patient-related outcome measures like the Facial Clinimetric Evaluation Scale and the Facial Disability Index are important tools to assess the subjective severity of the disease and psychosocial impact of Bell's palsy next to the motor deficits. Simplified subjective electronic grading systems like the eFACE and first automated image analysis systems have been introduced. Studies clarifying the role of antivirals for severe cases are urgently needed as well as studies on the role of salvage second line therapy after insufficient response to initial corticosteroid treatment. An international consensus on the outcome measures in diagnostics and follow-up is also needed.

Effect of an Intensified Combined Electromyography and Visual Feedback Training on Facial Grading in Patients With Post-paralytic Facial Synkinesis

Background: There is no current standard for facial synkinesis rehabilitation programs. The benefit and stability of effect of an intensified 10-day facial training combining electromyography and visual biofeedback training was evaluated.

Methods: Fifty-four patients (77.8% female; median age: 49.5 years) with post-paralytic facial synkinesis (median time to onset of paralysis: 31.1 months) were included in retrospective longitudinal study between January 2013 and June 2016. Facial function was assesses at baseline (T0), first days of training (T1), last day of training (T2), and follow-up visit (T3) at a median time of 6 months later using the House-Brackmann (HB) facial nerve grading system, Stennert index (SI), Facial Nerve Grading System 2.0 (FNGS 2.0), and Sunnybrook Facial Grading System (SFGS). Pairwise comparisons between the time points with post-hoc Bonferroni correction were performed.

Results: No significant changes of the gradings and subscores were seen between T0 and T1 (all p > 0.01). The 10-day combined and intensified feedback training between T1 and T2 improved facial symmetry and decreased synkinetic activity. Facial grading with the FNGS 2.0 or the SFGS were most suited to depict the training effect. FNGS 2.0, regional score, FNGS 2.0, synkinesis score, and FNGS 2.0 total score improved significantly (all p ≤ 0.0001). Both, the FNGS 2.0 and the SFGS showed the strongest improvement in the nasolabial fold/zygomatic and the oral region. Neither the age of the patient (r = 0.168; p = 0.224), the gender (r = 0.126; p = 0.363) nor the length of the interval between onset of the palsy and training start (r = 0.011; p = 0.886) correlated with the changes of the SFGS between T1 and T2. The results remained stable between T2 and T3 without any further significant change.

Conclusion: Intensified daily combined electromyography and visual biofeedback training over 10 days was effective in patients with facial synkinesis and benefits were stable 6 months after therapy.

Atlas of voluntary facial muscle activation: Visualization of surface electromyographic activities of facial muscles during mimic exercises

Complex facial muscle movements are essential for many motoric and emotional functions. Facial muscles are unique in the musculoskeletal system as they are interwoven, so that the contraction of one muscle influences the contractility characteristic of other mimic muscles. The facial muscles act more as a whole than as single facial muscle movements. The standard for clinical and psychosocial experiments to detect these complex interactions is surface electromyography (sEMG). What is missing, is an atlas showing which facial muscles are activated during specific tasks. Based on high-resolution sEMG data of 10 facial muscles of both sides of the face simultaneously recorded during 29 different facial muscle tasks, an atlas visualizing voluntary facial muscle activation was developed. For each task, the mean normalized EMG amplitudes of the examined facial muscles were visualized by colors. The colors were spread between the lowest and highest EMG activity. Gray shades represent no to very low EMG activities, light and dark brown shades represent low to medium EMG activities and red shades represent high to very high EMG activities relatively with respect to each task. The present atlas should become a helpful tool to design sEMG experiments not only for clinical trials and psychological experiments, but also for speech therapy and orofacial rehabilitation studies.

Computerized Sunnybrook facial grading scale (SBface) application for facial paralysis evaluation

BACKGROUND

The Sunnybrook facial grading scale is a comprehensive scale for the evaluation of facial paralysis patients. Its results greatly depend on subjective input. This study aimed to develop and validate an automated Sunnybrook facial grading scale (SBface) to more objectively assess disfigurement due to facial paralysis.

METHODS

An application compatible with iOS version 11.0 and up was developed. The software automatically detected facial features in standardized photographs and generated scores following the Sunnybrook facial grading scale. Photographic data from 30 unilateral facial paralysis patients were randomly sampled for validation. Intrarater reliability was tested by conducting two identical tests at a 2-week interval. Interrater reliability was tested between the software and three facial nerve clinicians.

RESULTS

A beta version of the SBface application was tested. Intrarater reliability showed excellent congruence between the two tests. Moderate to strong positive correlations were found between the software and an otolaryngologist, including the total scores of the three individual software domains and composite scores. However, 74.4% (29/39) of the subdomain items showed low to zero correlation with the human raters (κ<0.2). The correlations between the human raters showed good congruence for most of the total and composite scores, with 10.3% (4/39) of the subdomain items failing to correspond (κ<0.2).

CONCLUSIONS

The SBface application is efficient and accurate for evaluating the degree of facial paralysis based on the Sunnybrook facial grading scale. However, correlations of the software-derived results with those of human raters are limited by the software algorithm and the raters' inconsistency.

Role of Body Dysmorphic Disorder in Patients With Postparalytic Facial Synkinesis

OBJECTIVES/HYPOTHESIS

To evaluate the role of body dysmorphic disorder (BDD) in patients with postparalytic facial nerve syndrome with synkinesis (PFS).

STUDY DESIGN

A single-center retrospective cohort study.

METHODS

A total of 221 adults (74% women; median age: 44 years; median duration since onset of facial palsy: 1.6 years) were included. To diagnose BDD, the BDD Munich Module was used. Associations with House-Brackmann grading, Stennert index grading, Facial Clinimetric Evaluation (FaCE) survey, Facial Disability Index (FDI), general quality of life (SF-36), Beck Depression Inventory (BDI), and the Liebowitz Social Anxiety Scale (LSAS) was analyzed.

RESULTS

A total of 59 patients (27%) were classified as patients with BDD. Significant associations were found between the diagnosis of BDD and female gender and lower FDI, FaCE, and SF-36 scores and higher BDI and LSAS scores. Multivariate analysis revealed BDI, FaCE total score, and FaCE social function subscore as independent factors associated with BDD.

CONCLUSION

BDD was a relevant diagnosis in patients with PFS. A higher BDD level was associated with general and facial-specific quality of life and more psychosocial disabilities. Optimal treatment of PFS has to include these nonmotor dysfunctions.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:E2518-E2524, 2021.

An objective, markerless videosystem for staging facial palsy

Purpose

To propose a new objective, video recording method for the classification of unilateral peripheral facial palsy (UPFP) that relies on mathematical algorithms allowing the software to recognize numerical points on the two sides of the face surface that would be indicative of facial nerve impairment without positioning of markers on the face.

Methods

Patients with UPFP of different House–Brackmann (HB) degrees ranging from II to V were evaluated after video recording during two selected facial movements (forehead frowning and smiling) using a software trained to recognize the face points as numbers. Numerical parameters in millimeters were obtained as indicative values of the shifting of the face points, of the shift differences of the two face sides and the shifting ratio between the healthy (denominator) and the affected side (numerator), i.e., the asymmetry index for the two movements.

Results

For each HB grade, specific asymmetry index ranges were identified with a positive correlation for shift differences and negative correlation for asymmetry indexes.

Conclusions

The use of the present objective system enabled the identification of numerical ranges of asymmetry between the healthy and the affected side that were consistent with the outcome from the subjective methods currently in use.

Assessment and rehabilitation interventions for central facial palsy in patients with acquired brain injury: a systematic review

Objectives: To do a systematic review covering assessments and interventions for central facial palsy (CFP) in patients with acquired brain injury.Methods: PubMed, Embase, Cinahl, PsycInfo, and Web of Science were screened until April 2019. Assessments were defined as clinical- and instrumental tools and rating scales. Interventions were defined as rehabilitation interventions alleviating CFP.Results: 690 articles were screened based on the title and abstract. Interrater agreement was 98.12%. Sixteen articles were included: six clinical trials and 10 observational studies. Assessment: Commonest scale for assessing CFP was the House-Brackmann facial nerve Grading System. Strain gauges for measuring lip and cheek strength were applied in five studies and neurophysiological methods of assessing motor neuron pathways were applied in three studies. Interventions: An oral screen for improving lip strength was reported in three studies. Other interventions reported were neuromuscular electrical stimulation, Castillo Morales therapy, mirror therapy, exercises with electromyography feedback, and acupuncture.Conclusions: Scales for assessing peripheral facial palsy were applied for assessing CFP. Based on neurophysiological differences in the manifestation of peripheral facial palsy and CFP, these scales should be validated in patients with CFP. More studies on interventions for CFP are required before conclusions may be drawn about their effectiveness.

Utilization of Smartphone Depth Mapping Cameras for App-Based Grading of Facial Movement Disorders: Development and Feasibility Study

BACKGROUND

For the classification of facial paresis, various systems of description and evaluation in the form of clinician-graded or software-based scoring systems are available. They serve the purpose of scientific and clinical assessment of the spontaneous course of the disease or monitoring therapeutic interventions. Nevertheless, none have been able to achieve universal acceptance in everyday clinical practice. Hence, a quick and precise tool for assessing the functional status of the facial nerve would be desirable. In this context, the possibilities that the TrueDepth camera of recent iPhone models offer have sparked our interest.

OBJECTIVE

This paper describes the utilization of the iPhone's TrueDepth camera via a specially developed app prototype for quick, objective, and reproducible quantification of facial asymmetries.

METHODS

After conceptual and user interface design, a native app prototype for iOS was programmed that accesses and processes the data of the TrueDepth camera. Using a special algorithm, a new index for the grading of unilateral facial paresis ranging from 0% to 100% was developed. The algorithm was adapted to the well-established Stennert index by weighting the individual facial regions based on functional and cosmetic aspects. Test measurements with healthy subjects using the app were performed in order to prove the reliability of the system.

RESULTS

After the development process, the app prototype had no runtime or buildtime errors and also worked under suboptimal conditions such as different measurement angles, so it met our criteria for a safe and reliable app. The newly defined index expresses the result of the measurements as a generally understandable percentage value for each half of the face. The measurements that correctly rated the facial expressions of healthy individuals as symmetrical in all cases were reproducible and showed no statistically significant intertest variability.

CONCLUSIONS

Based on the experience with the app prototype assessing healthy subjects, the use of the TrueDepth camera should have considerable potential for app-based grading of facial movement disorders. The app and its algorithm, which is based on theoretical considerations, should be evaluated in a prospective clinical study and correlated with common facial scores.

Raising the Digital Profile of Facial Palsy: National Surveys of Patients' and Clinicians' Experiences of Changing UK Treatment Pathways and Views on the Future Role of Digital Technology

BACKGROUND

Facial nerve palsy leaves people unable to move muscles on the affected side of their face. Challenges exist in patients accessing facial neuromuscular retraining (NMR), a therapy used to strengthen muscle and improve nerve function. Access to therapy could potentially be improved through the use of digital technology. However, there is limited research available on patients' and clinicians' views about the potential benefits of such telerehabilitation based on their lived experiences of treatment pathways.

OBJECTIVE

This study aims to gather information about facial palsy treatment pathways in the United Kingdom, barriers to accessing NMR, factors influencing patient adherence, measures used to monitor recovery, and the potential value of emerging wearable digital technology.

METHODS

Separate surveys of patients with facial palsy and facial therapy specialists were conducted. Questionnaires explored treatment pathways and views on telerehabilitation, were co-designed with users, and followed a similar format to enable cross-referencing of responses. A follow-up survey of national specialists investigated methods used to monitor recovery in greater detail. Analysis of quantitative data was conducted allowing for data distribution. Open-text responses were analyzed using thematic content analysis.

RESULTS

A total of 216 patients with facial palsy and 25 specialist therapists completed the national surveys. Significant variations were observed in individual treatment pathways. Patients reported an average of 3.27 (SD 1.60) different treatments provided by various specialists, but multidisciplinary team reviews were rare. For patients diagnosed most recently, there was evidence of more rapid initial prescribing of corticosteroids (prednisolone) and earlier referral for NMR therapy. Barriers to NMR referral included difficulties accessing funding, shortage of specialist therapists, and limited awareness of NMR among general practitioners. Patients traveled long distances to reach an NMR specialist center; 9% (8/93) of adults reported traveling ≥115 miles. The thematic content analysis demonstrates positive attitudes to the introduction of digital technology, with similar incentives and barriers identified by both patients and clinicians. The follow-up survey of 28 specialists uncovered variations in the measures currently used to monitor recovery and no agreed definitions of a clinically significant change for any of these. The main barriers to NMR adherence identified by patients and therapists could all be addressed by using suitable real-time digital technology.

CONCLUSIONS

The study findings provide valuable information on facial palsy treatment pathways and views on the future introduction of digital technology. Possible ways in which emerging sensor-based digital technology can improve rehabilitation and provide more rigorous evidence on effectiveness are described. It is suggested that one legacy of the COVID-19 pandemic will be lower organizational barriers to this introduction of digital technology to assist NMR delivery, especially if cost-effectiveness can be demonstrated.

Development of a smartphone app for neuromuscular facial training

BACKGROUND

Several studies have demonstrated a significant benefit of neuromuscular facial training in the rehabilitation of patients with facial palsy. However, printed instructions for home training are often not of optimum quality and associated with low adherence to therapy. Professional guidance, e.g., by occupational therapists, is regarded as being of high quality, but is associated with a high cost burden, particularly in chronic forms of disease.

OBJECTIVE

The idea to develop a smartphone app for facial training arose from the above-described situation. The aim was to provide structured exercises for the mimic muscles in the sense of neuromuscular training with visual feedback via the front camera of the device.

MATERIALS AND METHODS

A native app architecture in iOS was chosen to implement the graphical and content-related concept. In the Apple Xcode (Apple, Cupertino, CA, US) development environment, the app's code was written in the Swift programming language (Apple) and the graphical user interface was created.

RESULTS

An app prototype was implemented that provides step-by-step instructions on selected mimic exercises via animated smileys. The duration and speed of the exercise can be varied within a limited range. In the development environment, the correct functionality of both physical and virtual devices was successfully tested.

CONCLUSION

App-based facial training offers attractive opportunities to motivate patients for improved adherence to treatment, which could hypothetically lead to a better outcome. Evaluation of this question is planned in a clinical trial after completion of the development.

[Development of a smartphone app for neuromuscular facial training. German Version]

BACKGROUND

Several studies have demonstrated a significant benefit of neuromuscular facial training in the rehabilitation of patients with facial palsy. However, printed instructions for home training are often not of optimum quality and associated with low adherence to therapy. Professional guidance, e.g., by occupational therapists, is regarded as being of high quality, but is associated with a high cost burden, particularly in chronic forms of disease.

OBJECTIVE

The idea to develop a smartphone app for facial training arose from the above-described situation. The aim was to provide structured exercises for the mimic muscles in the sense of neuromuscular training with visual feedback via the front camera of the device.

MATERIALS AND METHODS

A native app architecture in iOS was chosen to implement the graphical and content-related concept. In the Apple Xcode (Apple, Cupertino, California, US) development environment, the app's code was written in the Swift programming language (Apple) and the graphical user interface was created.

RESULTS

An app prototype was implemented that provides step-by-step instructions on selected mimic exercises via animated smileys. The duration and speed of the exercise can be varied within a limited range. In the development environment, the correct functionality of both physical and virtual devices was successfully tested.

CONCLUSION

App-based facial training offers attractive opportunities to motivate patients for improved adherence to treatment, which could hypothetically lead to a better outcome. Evaluation of this question is planned in a clinical trial after completion of the development.

Functional Outcome and Quality of Life After Hypoglossal-Facial Jump Nerve Suture

Background: To evaluate the face-specific quality of life after hypoglossal-facial jump nerve suture for patients with long-term facial paralysis.

Methods: A single-center retrospective cohort study was performed. Forty-one adults (46% women; median age: 55 years) received a hypoglossal-facial jump nerve suture. Sunnybrook and eFACE grading was performed before surgery and at a median time of 42 months after surgery. The Facial Clinimetric Evaluation (FaCE) survey and the Facial Disability Index (FDI) were used to quantify face-specific quality of life after surgery.

Results: Hypoglossal-facial jump nerve suture was successful in all cases without tongue dysfunction. After surgery, the median FaCE Total score was 60 and the median FDI Total score was 76.3. Most Sunnybrook and eFACE grading subscores improved significantly after surgery. Younger age was the only consistent independent predictor for better FaCE outcome. Additional upper eyelid weight loading further improved the FaCE Eye comfort subscore. Sunnybrook grading showed a better correlation to FaCE assessment than the eFACE. Neither Sunnybrook nor eFACE grading correlated to the FDI assessment.

Conclusion: The hypoglossal-facial jump nerve suture is a good option for nerve transfer to reanimate the facial muscles to improve facial motor function and face-specific quality of life.