role of laryngeal electromyography in vocal fold immobility

ABSTRACT

Vocal fold paralysis could be caused by a wide variety of etiological factors that interfere with the nerve supply of the larynx. To assess the utility of laryngeal-EMG as a diagnostic method for patients with immobile vocal folds and to evaluate its possible role as a prognostic indicator in the management of those cases. The study included 35 patients with unilateral vocal fold immobility [VFI] in addition to 10 normal individuals who served as controls. All patients were subjected to full history taking and thorough clinical examination and radiological investigations. Laryngeal EMG was performed for all the patients and controls. None of the control group showed abnormal EMG data while abnormal EMG findings were detected in 23 out of 35 of the patients' group i.e. the specificity of EMG was [100%] while the sensitivity was [65.7%] in detecting VFI. On clinical follow up with indirect laryngoscopy, 6 months later revealed recovery in 10 of the 25 cases [40%]. None of the recovered patients showed abnormal EMG data at presentation while 13 out of 15 cases of non-recovered patients showed abnormal EMG data i.e. the specificity of EMG was 100% while the sensitivity was 86.6% in predicting recovery in patients with VFI. The quantitative analysis of the interference pattern was more sensitive [65.7% and 86.6%] than the conventional methods of analysis [60% and 80%] in detecting and predicting recovery in patients with immobile vocal folds respectively. The clinical use of L-EMG was shown to be an efficient and objective test in the study of patients with immobile vocal folds and in predicting recovery of those cases