Respiratory Laryngeal Dystonia: Characterization and Diagnosis of a Rare Neurogenic Disorder

Abstract

Objectives/hypothesis: Respiratory laryngeal dystonia (RLD) is poorly understood and rarely reported in the literature. Patients have atypical laryngeal movement resulting in airway obstruction. This motion is neurogenic in nature, is constant while awake, nonepisodic, and non-trigger dependent. Given its rarity, it is often misdiagnosed for inducible laryngeal obstruction; however, it is refractory to medical and behavioral management. Although this condition has been addressed in the literature, this report is the largest case series characterizing presenting symptomology, multimodal treatment outcomes, and longitudinal course of these patients, and proposes a set of diagnostic criteria to aid in clinical identification of RLD patients. Our objectives were to characterize RLD clinically and offer diagnostic guidelines to clinicians.

Study design: A prospective case series with a retrospective analysis at a tertiary referral center.

Methods: A review of clinical records and videostroboscopic analysis of 16 patients treated for respiratory laryngeal dystonia from October 2005 to October 2018 was performed.

Results: Sixteen patients with respiratory laryngeal dystonia were included. The common features of this group were persistent, nonepisodic dyspnea and stridor with laryngoscopic evidence of paradoxical vocal fold motion. Our patients had no structural neurologic abnormalities. These patients typically failed respiratory retraining therapy and medical management of laryngeal irritants. In our series, 100% of patients underwent respiratory retraining therapy, 68.8% received laryngeal botulinum toxin injection, and 31.3% required tracheostomy.

Conclusions: RLD is a rare and challenging condition. The disorder can be severely disabling, and treatment options appear limited. A multidisciplinary approach may be helpful. Some patients responded to laryngeal botulinum injection and medical management, whereas others required tracheostomy for symptom control. Laryngoscope, 2020.

Keywords: Respiratory laryngeal dystonia; functional dysphonia; laryngeal; laryngeal retraining; laryngology; speech and language pathology; stroboscopy.