Prognostic Value of Laryngeal Electromyography in Patient with Vocal Cord Paralysis

J Korean Assoc EMG Electrodiagn Med 2009;11(2):105-109.
Published online December 31, 2009.

Abstract

Objective: To assess the prognostic value of laryngeal electromyography in patients with vocal cordparalysis and to determine which element of laryngeal electromyography is important for predictingrecovery of vocal cord paralysis.
Methods: Twenty nine cases of vocal cord paralysis were diagnosed by laryngeal electromyography andlaryngoscopy within 6 months after the onset of symptom. The elements of laryngeal electromyographywere abnormal spontaneous activity, motor unit action potential, and interference pattern. Follow-uplaryngoscopy was performed to evaluate the recovery of vocal cord paralysis by viewing the vocal cordmotion.
Results: Of 29 cases of vocal cord paralysis, 10 cases (34.5%) had resolved vocal cord motion, whereas19 (65.5%) had persistent vocal cord paralysis on follow-up laryngoscopy examination. Prevalence ofabnormal spontaneous activity and abnormal motor unit action potential were not different between thetwo groups, whereas interference pattern was significantly different (p<0.05). Absence or single interferencepattern reflected the permanent vocal cord paralysis.
Conclusion: Laryngeal electromyography was a valuable test to predict recovery from the vocal cordparalysis. Initial interference pattern was an important element to predict vocal cord motion.

Key Words: Vocal cord paralysis, Prognosis, Electromyography