Voice dysfunction following thyroidectomy

ABSTRACT

Voice dysfunction after thyroidectomy is not rare, and is generally reported in terms of recurrent laryngeal nerve [RLN] or superior laryngeal nerve [SLN] injuries. However, voice dysfunction can occur without laryngeal nerves injuries. Prompt recognition of causes of dysphonia is essential so that relevant therapeutic decision allows early management. The aim is to analyze voice change after thyroidectomy for patients with normal pre-operative voice. The study included 30 patients who had developed voice change within 6 months after thyroidectomy. They were subjected to voice evaluation, indirect laryngoscopy, videostroboscopy and electromyography [EMG]. It was found that dysphonia after thyroid surgery was caused by neurogenic causes [RLN and SLN injuries] in 23 patients [76.7%], non-neurogenic causes in 5 patients [16.7%] and combined causes in 2 patients [6.6%]. EMG studies revealed complete denervation in 6 patients [20] and incomplete denervation [paresis] in 19 patients [63.3%]. Post-thyroidectomy dysphonias are not rare. Injuries of the RLN constitute the main cause. Non-neurogenic injury is another contributing factor. Diagnosis is essential for early management through videostroboscopy and EMG which is specific to differentiate between neurogenic and traumatic injuries and to detect complete or incomplete denervation