Quantitative laryngeal electromyography (LEMG) in unilateral vocal fold paralysis: Developing normative values using the opposite normal mobile vocal fold

• Published in: Auris, nasus, larynx nasus, larynx, 2021-12, Vol.48 (6), p.1140-1149
• Main Authors: Chen, Irise Hoi Khin, Remli, Rabani, Azman, Mawaddah, Ubaidah, Muhammad Azhan, Mohamed, Abdullah Sani, Baki, Marina Mat
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Analysis of Variance; Cross-Sectional Studies; Electromyography - methods; Female; Humans; Laryngeal electromyography; Laryngeal Muscles - physiology; Male; Middle Aged; Qualitative laryngeal electromyography; Quantitative laryngeal electromyography; Reference Values; Turns and amplitude analysis; Unilateral vocal fold paralysis; Vocal Cord Paralysis - diagnosis; Vocal Cord Paralysis - physiopathology; Vocal Cords - physiology
• ISSN: 0385-8146; 1879-1476
• DOI: 10.1016/j.anl.2021.03.028

Laryngeal electromyography (LEMG) is used to confirm neuropathy; traditionally, it is evaluated qualitatively. This study aimed to develop normative values for the thyroarytenoid-lateral cricoarytenoid (TA-LCA) muscle complex by determining the mean turns (MT) and mean amplitudes (MA) using the opposite normal mobile vocal fold in unilateral vocal fold paralysis (VFP). This study also compared the MT and MA of the paralyzed vocal fold with that of the normal side and analyzed their correlations. This is a cross-sectional study in which 77 patients (18 males, 59 females, mean age of 48) with unilateral VFP with an opposite normal mobile vocal fold underwent LEMG with a standardized protocol. Koufman gradings and MT and MA were used for the qualitative and quantitative evaluations. Mann–Whitney U test was performed to compare the median of the turns and amplitudes between the opposite normal mobile vocal fold and the paralyzed side. A linear-scale graphical “cloud” of the normal TA-LCA muscle complex was generated using logarithmic regression analysis. The qualitative and quantitative parameters were analyzed using multiple analysis of variance and Kruskall–Wallis test. Post-hoc analysis was performed to further determine the differences of the significance between both parameters. The correlation between the qualitative and quantitative parameters was analyzed using Spearman correlation. The MT and MA were significantly higher for the normal TA-LCA muscle complex than the paralyzed side (582 vs. 336; 412 vs. 296, respectively) and the median of the turns and amplitudes were significantly lower in the paralyzed side with p-values