Although recognized as a valuable diagnostic tool for more than 60 years, many laryngologists do not routinely use laryngeal electromyography (LEMG). This may be due to a persisting lack of agreement on methodology, interpretation, validity, and clinical application of LEMG. To achieve consensus in these fields, a laryngeal electromyography working group of European neurolaryngologic experts was formed in order to (1) evaluate guidelines for LEMG performance and (2) identify issues requiring further clarification. To obtain an overview of existing knowledge and research, English-language literature about LEMG was identified using Medline. Additionally, cited works not detected in the initial search were screened. Evidence-based recommendations for the performance and interpretation of LEMG and also for electrostimulation for functional evaluation were considered, as well as published reports based on expert opinion and single-institution retrospective case series. To assess the data obtained by this literature evaluation, the working group met five times and performed LEMG together on more than 20 patients. Subsequently, the results were presented and discussed at the 8th Congress of the European Laryngological Society in Vienna, Austria, September 1-4, 2010, and consensus was achieved in the following areas: (1) minimum requirements for the technical equipment required to perform and record LEMG; (2) best practical implementation of LEMG; (3) criteria for interpreting LEMG. Based on this consensus, prospective trials are planned to improve the quality of evidence guiding the proceedings of practitioners.

2b Laryngoscope, 126:1810-1816, 2016.

2b Laryngoscope, 127:1838-1844, 2017.

4. Laryngoscope, 128:1152-1156, 2018.

To achieve consensus in the methodology, interpretation, validity, and clinical application of laryngeal electromyography (LEMG), a working group on neurolaryngology from the European Laryngological Society (ELS) was founded in 2010. The main task of the working group was to teach key techniques like LEMG procedures. The objective of this study was to collect information on the teaching techniques used and describe them. A multicenter registry was created to analyze the data collected from LEMGs in 14 departments. We screened how often different departments participated in teaching events. Teaching events were classified retrospectively: presentations at conferences and meetings; workshops with hands-on training on patients; workshops with hands-on training on animal models; workshops with hands-on training on anatomic specimens; and supervision by experts to perform LEMG together. Both, supervision to perform LEMG together and the total number of PCA-LEMGs (r = 0.713), as well as supervision to perform LEMG together and the PCA/total-number-of-LEMG ratio (r = 0.814) were correlated significantly (p < 0.05). Similarly, the sum of teaching events was correlated significantly with the total number of PCA-LEMGs (r = 0.605), and so did the sum of teaching events with the PCA/total-number-of-LEMG ratio (r = 0.704). Participation in hands-on training in humans was correlated significantly with the PCA/total-number-of-LEMG ratio (r = 0.640). The data presented herein suggest that multimodal teaching techniques are most effective. To promote multimodal learning an interactive webpage ( http://www.lemg.org) providing videos and animations, and the possibility to discuss cases with other experts was established.

Microlaryngoscopic enlargement techniques have been the standard treatment for bilateral vocal fold paralysis (BVFP) for decades. Laryngeal pacing is a promising alternative treatment based on the electrostimulation of the posterior cricoarytenoid (PCA) muscle. This paper reports on the results of a pre-clinical study aiming to evaluate this method. Eight Göttingen mini-pigs were implanted with a laryngeal pacemaker (LP) implant prototype and with two LP electrodes, one in each PCA muscle. The 6-week follow-up included endoscopic stimulation controls in general anaesthesia and radiographic controls of electrode integrity and position stability. Stimulation parameters for optimal glottal opening were evaluated via videolaryngoscopy. Histopathology was performed upon conclusion of the study. 7/8 (87.5 %) animals were successfully implanted with the LP implant prototype and two LP electrodes. In general, stimulation was effectively delivered and correlated with the expected PCA muscle activation. 2/14 (14.3 %) electrodes dislocated and 1/14 (7.1 %) electrode tip broke. The LP system used in this experiment to induce vocal fold abduction by means of selective functional electrical stimulation of the PCA showed promising results. It may be a valid alternative to the current golden standard for BVFP treatment. Clinical studies are needed to confirm the medical relevance of the LP.

Objectives/Hypothesis: An immobile vocal fold due to recurrent laryngeal nerve (RLN) injury usually shows no gross signs of atrophy and lies near the midline. In 1881, Felix Semon proposed that this phenomenon was due to a selective injury of nerve fibers supplying the posterior cricoarytenoid muscle (PCA) and supported this with postmortem proof of selective PCA atrophy. In recent decades, evidence has emerged that the RLN regenerates after injury but does not always result in useful motion of the vocal folds. It has been proposed that this is caused by laryngeal synkinesis. Laryngeal synkinesis describes a random distribution of regenerated nerve fibers to opposing vocal fold muscles. This study was conducted to clarify the relative contribution of these two potential pathomechanisms in our patient population. Study Design: Retrospective case analysis. Methods: Retrospective analysis of laryngeal EMG results from cases with RLN paralysis of at least 6 months duration seen at our neurolaryngology clinic. Results: Out of 118 PCA EMGs, there was not a single normal or near-normal tracing, whilst 33.3% of TA EMGs indicated normal or near normal innervation. PCA EMGs showed signs of persistent high-grade partial denervation (41.5%) as a sign of atrophy, moderate or strong synkinesis (21.2%), or a combination of both (37.3%). Conclusions: In chronic RLN paralysis the intrinsic laryngeal muscles are affected to different extents either by atrophy or synkinesis or a combination of both. The PCA is always affected. The lesser damage to TA innervation explains the commonly seen maintenance of vocal fold muscle bulk.

PurposeLaryngeal electromyography (LEMG) has been considered as gold standard in diagnostics of vocal fold movement impairment, but is still not commonly implemented in clinical routine. Since the signal interpretation of LEMG signals (LEMGs) is often a subjective and semi-quantitative matter, the goal of this study was to evaluate the inter-rater reliability of neurolaryngologists on LEMGs of volitional muscle activity.MethodsFor this study, 52 representative LEMGs of 371 LEMG datasets were selected from a multicenter registry for a blinded evaluation by 7 experienced members of the neurolaryngology working group of the European Laryngological Society (ELS). For the measurement of the observer agreement between two raters, Cohen’s Kappa statistic was calculated. For the interpretation of agreements of diagnoses among the seven examiners, we used the Fleiss’ Kappa statistic.ResultWhen focusing on the categories “no activity”, “single fiber pattern”, and “strongly decreased recruitment pattern”, the inter-rater agreement varied from Cohen’s Kappa values between 0.48 and 0.84, indicating moderate to near-perfect agreement between the rater pairs. Calculating with Fleiss’ Kappa, a value of 0.61 showed good agreement among the seven raters. For the rating categories, the Fleiss’ Kappa value ranged from 0.52 to 0.74, which also showed a good agreement.ConclusionA good inter-rater agreement between the participating neurolaryngologists was achieved in the interpretation of LEMGs. More instructional courses should be offered to broadly implement LEMG as a reliable diagnostic tool in evaluating vocal fold movement disorders in clinical routine and to develop future algorithms for therapy and computer-assisted examination.