The use of fibrolaryngoscopy in muscle tension dysphonia in telemarketers

Introduction: Muscle tension dysphonia (MTD) is a voice disorder in the absence of current organic laryngeal pathology, without obvious psychogenic or neurological aetiology. The laryngeal features of MTD include a posterior glottal gap and supraglottic hyperfunctional activities; however, it remains unclear if these features are specific to MTD. This report aims to compare the laryngeal features in telemarketer patients with MTD versus non-dysphonic control subjects. Methods: We reported on an observational, analytic and transversal study. Fiberoptic nasal endoscopy was performed on 57 patients (28 telemarketers with MTD and 29 control subjects). These random-sequence videotapes were independently rated by an expert laryngologist according to the modified Morrison and Rammage classification. In addition, a questionnaire about vocal symptoms and other details was completed. Results: The posterior glottal gap was the most common feature in telemarketers with MTD, while incomplete glottal gap was observed more frequently in non-dysphonic patients. More than 70% of the videotapes were rated as pathologic. There was no statistical difference in the prevalence of normal features or bowing glottal gap between patients and control subjects. Anterior-posterior supraglottic contraction was more frequent in the control group. The major symptoms found were: voice gets tired quickly, increased vocal effort and neck tension. Conclusions: The heterogeneity in the laryngeal features in telemarketers with MTD seen under fibroscopy and their presence among the non-dysphonic population suggest that they cannot determine by themselves the diagnosis of MTD. (C) 2011 Elsevier Espana, S. L. All rights reserved.