[Laryngeal electromyography in diagnosis and treatment of voice disorders]. / Electromiografía laríngea en el diagnóstico y tratamiento de los trastornos de la voz.

INTRODUCTION AND OBJECTIVES: Laryngeal electromyography, together with clinical evaluation, is a valuable tool in voice disorder management. It assesses the integrity of laryngeal nerves and muscles, contributing to the diagnosis of many diseases, especially laryngeal movement disorders. Our purpose was to describe the experience of the first Spanish series with laryngeal electromyography in evaluating voice disorders. METHODS: A prospective study was designed to evaluate laryngeal movement disorders with laryngeal electromyography. Both the cricothyroid and thyroarytenoid muscles were tested routinely and, in some cases, the posterior cricoarytenoid muscle. The laryngeal electromyography technique and result interpretation were performed by a laryngologist and a neurophysiologist. RESULTS: We included 110 patients, with the most common symptom being dysphonia. Laryngeal electromyography was performed in 85% of cases. Primary diagnosis before electromyography was laryngeal immobility. Positive predictive value for diagnosis in cases of paralysis was 88%. CONCLUSIONS: Laryngeal electromyography is a useful adjunct, together with clinical evaluation, for diagnosis and management of motion abnormalities in the larynx in patients who present with dysphonia.

[Analysis of changes in the spectrogram following endotracheal intubation]. / Análisis de los cambios en el espectrograma tras la intubación endotraqueal.

INTRODUCTION AND OBJECTIVES: Voice alteration is a common event following endotracheal intubation. The objective of this study is to describe strobolaryngoscopic and spectrogram changes after endotracheal intubation, and attempt to identify a relationship between these changes and also with anaesthetic variables. MATERIAL AND METHOD: Thirty-eight patients who underwent endotracheal intubation for otological surgery were studied prospectively. None of these subjects had a history of voice problems or prior cervical surgery, and they did not consume alcohol or tobacco. The patients were studied prior to the operation and 3 hours, 24 hours, and 7 days after surgery. Laryngeal morphology was explored by strobolaryngoscopy. The vocal output was examined by means of the GRABS scale, acoustic analysis and spectrogram. RESULTS: Strobolaryngoscopy was normal 24 hours after surgery in all but 2 subjects, in whom it later returned to normal. Spectrography, acoustic analysis (jitter and shimmer), and GRABS scale all showed an initial worsening of voice production after surgery when compared to pre-operative values, followed by a recovery of normal values 1 week after surgery. No statistical correlation was found between voice output and anaesthetic variables. CONCLUSIONS: Although there are temporary voice changes in subjects undergoing endotracheal intubation during the early post-operative period, these recover to normal parameters within 7 days after surgery. These changes occur even in the absence of strobolaryngoscopic changes.