Unilateral and bilateral recurrence of inferior laryngeal nerve paralysis

Abstract

Unilateral recurrent nerve paralysis leads to glottic insufficiency, causing a significant lack of vocal ability. In contrast, bilateral palsies present with stridor on inspiration due to glottic stenosis. Most of the underlying lesions are iatrogenic, with thyroid surgery being the single most important causative factor. However, a variety of different reasons can lead to such a condition. Whenever aetiology is uncertain a complete diagnostic work-up is mandatory. Indirect laryngoscopy confirms the diagnosis. Laryngeal electromyography is of great value because it differentiates between paralysis and ankylosis of the cricoarytaenoid joint. Moreover, in many cases laryngeal electromyography provides a reliable prognosis of clinical outcome. While unfavorable results can be predicted with high accuracy, correct prognosis of complete recovery is more difficult. Speech therapy is the treatment of choice in case of unilateral recurrent nerve palsy. Only if a significant glottal gap persists medialization procedures may become useful for voice improvement. Endoscopic as well as open approaches are available for this purpose. Bilateral recurrent nerve palsies need to be addressed surgically in the vast majority of cases. Today, a variety of endoscopic techniques for widening the glottic airway are available. Compared to permanent tracheostomy these procedures have much less impact on the patient's quality of life and should be preferred whenever possible. Inevitably, voice quality is traded for airway normalisation. However, modern surgical techniques accomplish very tolerable phonatory results.