The Laryngoscope C 2014 The American Laryngological, V

Rhinological and Otological Society, Inc.

Laryngeal Electromyography and Prognosis of Unilateral Vocal Fold Paralysis—A Long-term Prospective Study Chen-Chi Wang, MD; Ming-Hong Chang, MD; Armando De Virgilio, MD; Rong-San Jiang, MD, PhD; Hsiu-Chin Lai, SLP; Ching-Ping Wang, MD; Shang-Heng Wu, MD; Shih-An Liu, MD, PhD Objectives/Hypothesis: To confirm the value of using laryngeal electromyography (LEMG) to predict the long-term prognosis of unilateral vocal fold paralysis (UVFP), and elucidate the adequate timing of LEMG. Study Design: Prospective cohort prognosis study. Methods: The LEMG data of 84 patients with UVFP were prospectively collected, and 81 patients received follow-up at least 6 months after symptom onset. If the paralyzed vocal fold had 75% motion with obvious abduction during inspiration, we defined the patient has having had motion recovery. Except for patients who recovered vocal motion 2 months after symptom onset achieved the highest accuracy (90.6%), sensitivity (92.0%), specificity (66.7%), and PPV (97.9%). The natural history of UVFP has not been clearly established, and the potential timing for spontaneous recovery varies from one clinical scenario to another. However, Hirano et al.14 suggested excluding patients from LEMG testing 6 months after symptom onset based on their impression that few patients recovered after that interval. Therefore, permanent laryngeal framework surgery is usually indicated clinically for patients with UVFP 6 months after symptom onset. However, in our present study, only 33% (3/9) of patients with recovery were within 6 months from symptom onset. It seems that the 6-month criterion is arbitrary and unreliable. Therefore, more objective adjuvant guidance is needed when LEMG is used for management of UVFP. LEMG has often been dismissed as being a subjective test, particularly as to judgments regarding the degree of recruitment. According to our result, the median recruitment reduction was 80% in the LEMG-positive group and 10% in the LEMG-negative group. It seems that it is usually not hard to dichotomize patients to poor prognosis or good prognosis based on recruitment reduction. Furthermore, when LEMG is performed by an experienced neurologist familiar with electrodiagnostic medicine and following unambiguous preset rules, as in our previous study and the present study, the level of accuracy remained high. Because clinical electrophysiology is a fundamental part of resident training in neurology but not in otorhinolaryngology, we suggest laryngologists and neurolLaryngoscope 125: April 2015

902

ogists should work as a team. The European Laryngological Society also proposed this type of cooperation as a guideline for LEMG.9 However, further investigation by other cooperative teams is needed to confirm the reliability of our preset rules and findings. In addition, Statham et al.15 and Smith et al. 16 have proposed quantitative LEMG criteria, such as “turns and amplitudes,” to improve the prediction of motion recovery in paralyzed vocal folds in their retrospective studies with a short-term mean follow-up of 3 months. However, the automatic algorithms have not been widely established yet.9 In Smith’s pioneer quantitative LEMG study,16 they integrated both qualitative and quantitative LEMG data and retrospectively categorized their patients to poor, fair, poor/fair, and excellent prognosis groups. The value of quantitative LEMG needs to be confirmed with a prospective study using purely quantitative LEMG data with a long-term follow-up in the future. By applying our simple semiquantitative rules, we found that the PPV (93.0%) was similar to that (89.5%) reported by Smith et al.16 and acceptable in guiding the management of UVFP. The reality is that the chance of spontaneous recovery was very low in this study, and 88.9% (72/81) of our study subjects did not recover vocal fold function. A positive result from a simple semiquantitative rule could therefore confirm this poor result. Reviewing another retrospective study cited in Rickert et al.’s meta-analysis,6 the recovery rate is variable from Sittel et al.’s 8.1% (9/111)17 to Gupta and Bastian’s 50% (9/18).18 In our previous study cited by Richert et al.’s meta-analysis, the recovery rate was 29% (13/45). Obviously, we could not predict what kind of patient we would encounter during the period of study. That is why we need LEMG to help us differentiate prognosis and guide further treatment. Although the percentage of patients with recovery varies in different studies, the association of LEMG result and prognosis still remains significant. Another limitation of this study is the outcome measurement. We used vocal fold motion recovery as an end point, which was also used in other studies in Rickert et al.’s meta-analysis.6 However, according to the observation of Crumley,19 some UVFP patients may have favorable synkinesis (aberrant reinnervation) with little or no phonatory deficit, although there is no recovery of vocal fold motion. Because we could not only observe patients without any treatment, and HA injection changed the patients’ phonatory function, we were unable to use spontaneous function recovery as a second Wang et al.: LEMG and Long-term Prognosis of UVFP

end point in this study. In addition, the role of diagnosing synkinesis in UVFP remains undetermined. Crumley commented that LEMG may eventually assist the laryngologist in establishing synkinesis diagnosis, but currently not enough normative data exist for confirming laryngeal synkinesis unequivocally in every case.20 Furthermore, our study protocol did not contain performing LEMG data at last follow-up. Therefore, electrical recovery could not be used as another end point in our article. Recently, Statham et al. proposed that detecting synkinesis might improve the accuracy of LEMG to predict prognosis of UVFP in their retrospective study.21 The synkinesis testing was positive in 9.7% of their cohort. It seems that the synkinesis test is a potential adjunct procedure to improve the NPV and sensitivity of LEMG, and they concluded that the issue needs further investigation and validation.

CONCLUSION With a long-term prospective follow-up, this study confirmed that our LEMG rules can provide reliable prognostic information for UVFP. For patients with positive LEMG findings, the chance of recovery of vocal fold motion will be very low. If LEMG is performed more than 2 months after the symptom onset, the PPV could be improved from 93.0% to 97.9%. Surgeries (such as thyroplasty type I or arytenoid adduction) could be performed as soon as possible after a positive LEMG finding.

Acknowledgments The authors thank Ms. Anting Yu for her help in collecting the data.

BIBLIOGRAPHY 1. Yamada M, Hirano M, Ohkubo H. Recurrent laryngeal nerve paralysis: a 10-year review of 564 patients. Auris Nasus Larynx 1983;10(Suppl): S1–S15.

Laryngoscope 125: April 2015

2. Havas T, Lowinger D, Priestley J. Unilateral vocal fold paralysis: causes, options and outcomes. Aust N Z J Surg 1999;69:509–513. 3. Misono S, Merati AL. Evidence-based practice: evaluation and management of unilateral vocal fold paralysis. Otolaryngol Clin North Am 2012; 45:1083–1108. 4. Weddel GB, Pattle RE. The electrical activity of voluntary muscle in man under normal and pathological conditions. Brain 1944;67:178–257. 5. Wang CC, Chang MH, Wang CP, Liu SA. Prognostic indicators of unilateral vocal fold paralysis. Arch Otolaryngol Head Neck Surg 2008;134: 380–388. 6. Rickert SM, Childs LF, Carey BT, Murry T, Sulica L. Laryngeal electromyography for prognosis of vocal fold palsy: a meta-analysis. Laryngoscope 2012;122:158–161. 7. Blitzer A, Crumley RL, Dailey SH, et al. Recommendations of the Neurolaryngology Study Group on laryngeal electromyography. Otolaryngol Head Neck Surg 2009;140:782–793. 8. Sataloff RT, Mandel S, Mann EA, Ludlow CL. Practice parameter: laryngeal electromyography (an evidence-based review). Otolaryngol Head Neck Surg 2004;130:770–779. 9. Volk GF, Hagen R, Pototschnig C, et al. Laryngeal electromyography: a proposal for guidelines of the European Laryngological Society. Eur Arch Otorhinolaryngol 2012;269:2227–2245. 10. Wang CC, Chang MH, Jiang RS, et al. Laryngeal electromyographyguided hyaluronic acid vocal fold injection for unilateral vocal fold paralysis—a prospective long term follow up outcome report. JAMA Otolaryngol Head Neck Surg. In press. 11. Wang CC, Chang MH. A proposal to extend application of laryngeal electromyography (LEMG)-guided vocal fold injection to treatment of unilateral vocal fold paralysis to enhance clinical popularity of LEMG: response to the paper by G.F. Volk et al. Eur Arch Otorhinolaryngol 2013;270:1563–1565. 12. Seddon H. Three types of nerve injury. Brain 1943;66:237–288. 13. Crumley RL. Laryngeal synkinesis: its significance to the otolaryngologist. Ann Otol Rhinol Laryngol 1989;98:87–92. 14. Hirano M, Nosoe I, Shin T, Maeyama T. Electromyography for laryngeal paralysis. In: Hirano M, Kirchner J, Bless D, eds. Neurolaryngology: Recent Advances. 1st ed. Boston, MA: College Hill; 1987:232–248. 15. Statham MM, Rosen CA, Nandedkar SD, Munin MC. Quantitative laryngeal electromyography: turns and amplitude analysis. Laryngoscope 2010;120:2036–2041. 16. Smith LJ, Rosen CA, Niyonkuru C, Munin MC. Quantitative electromyography improves prediction in vocal fold paralysis. Laryngoscope 2012; 122:854–859. 17. Sittel C, Stennert E, Thumfart WF, Dapunt U, Eckel HE. Prognostic value of laryngeal electromyography in vocal fold paralysis. Arch Otolaryngol Head Neck Surg 2001;127:155–160. 18. Gupta SR, Bastian RW. Use of laryngeal electromyography in prediction of recovery after vocal cord paralysis. Muscle Nerve 1993;16:977–978. 19. Crumley RL. Laryngeal synkinesis revisited. Ann Otol Rhinol Laryngol 2000;109:365–371. 20. Crumley RL. Unilateral recurrent laryngeal nerve paralysis. J Voice 1994; 8:79–83. 21. Statham MM, Rosen CA, Smith LJ, Munin MC. Electromyographic laryngeal synkinesis alters prognosis in vocal fold paralysis. Laryngoscope 2010;120:285–290.

Wang et al.: LEMG and Long-term Prognosis of UVFP

903

Laryngeal electromyography and prognosis of unilateral vocal fold paralysis--a long-term prospective study.

To confirm the value of using laryngeal electromyography (LEMG) to predict the long-term prognosis of unilateral vocal fold paralysis (UVFP), and eluc...
289KB Sizes 0 Downloads 10 Views