Electromyography study and follow-up of bilateral recurrent laryngeal nerve paralysis after thyroid gland operations

Abstract

Bilateral recurrent laryngeal nerve (RLN) palsies result in dyspnea and often require further surgery to secure an adequate airway for safe respiration. The present study was devised to determine a predictive value of laryngeal electromyography (LEMG) and if it has therapeutic consequences. In a retrospective study of 63 patients with bilateral recurrent laryngeal nerve palsies after thyroid gland surgery we compared the results of LEMG from the thyroarytenoid muscles with the spontaneous recovery rate of vocal cord mobility. A tracheostomy had to be performed in 18 patients because of unsafe dyspnea, while a unilateral lateral cord fixation had to be carried out in 20 patients. Primary thyroidectomies as treatment for benign goiters showed spontaneous normalization of unilateral or bilateral vocal cord mobility in 75% of cases versus 36% after revision thyroidectomies. Single LEMG correctly predicted prognosis in 78% of patients. In all, LEMG was found to be of value in the assessment of bilateral recurrent laryngeal nerve palsies. Findings also showed that a lateral cord fixation should be planned after a 9-month waiting period. When a patient refuses a tracheostomy lateral cord fixation can be performed at an earlier time, with the use of repeated LEMGs to predict whether or not a corrective surgery.