Disfonía por tensión muscular: concepto y criterios diagnósticos / Muscle tension dysphonia: concept and diagnostic criteria

Introducción. La disfonía por tensión muscular fue definida, desde 1983, como un desorden que ocasiona un desbalance en las fuerzas de tensión muscular laríngea sin evidencia de patología estructural o neurológica. Denominado también disfonía por tensión muscular, tipo 1, este desorden aún no tiene estandarizadas las características que en la práctica han sido consideradas parte de su diagnóstico.Objetivo. Revisar la información actual, no mayor a cinco años, sobre disfonía por tensión muscular para unificar criterios y diagnósticos actuales.Metodología. Se realizó una búsqueda sistemática a través de las bases de datos PubMed, Google Scholar y Cochrane. Los términos MESH utilizados fueron: dis-fonía por tensión muscular, disfonía funcional, disfonía hipercinética y fatiga vocal. Criterios de inclusión: artículos publicados en revistas arbitradas, sin importancia del diseño y antigüedad no mayor a cinco años. Criterios de exclusión: artículos cuyo enfoque principal no fuera disfonía por tensión muscular y con idioma diferente al inglés o español.Resultados. Dos estudios refieren mayor patología en mujeres que hombres; cuatro investigaciones reportan presión subglótica aumentada (>90 mmHg); tres trabajos reportaron medidas fonatorias; un trabajo propone video de alta resolución como demostración de hiperfunción vocal; una investigación evaluó onda mucosa por elec-troglotografía; una investigación estudió el uso de resonancia magnética funcional; otro trabajo propuso un estudio piloto de evaluación de flujo sanguíneo de músculos infrahioideos. Otro trabajo hace una revisión del uso de métodos diagnósticos.Conclusiones. Los parámetros de mayor peso fueron pico cepstral y presión sub-glótica. Aún es necesario ampliar el conocimiento con nuevas investigaciones que permitan criterios universales

Introduction. Muscle tension dysphonia has been defined since 1983 as a disorder in which there is an imbalance in laryngeal muscle tension forces, without evidence of structural or neurological pathology; it has also been called type I muscle tension dysphonia. The characteristics that in practice have been considered part of the di-agnosis are not standardized.Objective. To review current information, not older than 5 years, on muscle tension dysphonia, unifying current diagnostic criteria.Methodology. A systematic search was carried out through the Pub Med, Google scholar and Cochrane databases. The MESH terms used were: muscle tension dys-phonia, functional dysphonia, hyperkinetic dysphonia, and vocal fatigue. Inclusion criteria: articles published in peer-reviewed journals, regardless of design and pub-lished no more than 5 years before. Exclusion criteria: articles whose main focus was not muscle tension dysphonia and with a language other than English or Spanish.Results. Two studies report more pathology in women than men; four investiga-tions report increased subglottic pressure (> 90 mmHg); three studies reported pho-natory measures; a work proposes high resolution video as a demonstration of vo-cal hyperfunction; an investigation evaluated mucosal wave by electroglottography; an investigation studied the use of functional magnetic resonance imaging; another work proposed a pilot study of infrahyoid muscle blood flow assessment: another work reviews the use of diagnostic methods.Conclusions. The parameters of greater weight were cepstral peak and subglottic pressure. It is still necessary to expand the knowledge with new research that allows universal criteria

Clinical Application of Botulinum Toxin to Functional Dysphonia

Functional dysphonia (FD) is a disease entity which includes various voice disorders in the absence of structural or neurologic laryngeal pathology. Muscle tension dysphonia (MTD), psychogenic dysphonia are representative FD with completely different pathogenesis. Therefore there is no standard treatment modality for FD, the first step of treatment of FD is differentiating patient's voice symptoms from other organic voice disorders and other functional voice problems. MTD is a functional voice disorder caused by hyperfunction of intrinsic and extrinsic laryngeal musculature. Symptoms include increased vocal effort, roughness, fatigue and odynophonia. First line for MTD is indirect or direct voice therapy. Unfortunately, many patients with MTD improve with voice therapy alone. For these patients, various modalities tried; lidocaine application, surgical excision of the false vocal folds, and botulinum toxin injection, etc. Botulinum toxin injections are widely used in the field of otolaryngology, especially for spasmodic dysphonia. However, its use in FD or MTD has only been described in few case reports. The aim of this lecture is to evaluate the feasibility of botulinum toxin injection for FD, especially MTD.

Differential Diagnosis between Neurogenic and Functional Dysphonia

Voice disorder is classified into three categories, structural, neurogenic and functional dysphonia. Neurogenic dysphonia refers to a disruption in the nerves controlling the larynx. Common examples of this include complete or partial vocal cord paralysis, spasmodic dysphonia. Also it occurs as part of an underlying neurologic condition such as Parkinson's disease, myasthenia gravis, Lou Gehrig's disease or disorder of the central nervous system that causes involuntary movement of the vocal folds during voice production. Functional dysphonia is a voice disorder in the absence of structual or neurogenic laryngeal characteristics. A near consensus exist that Muscle tension dysphonia (MTD) is functional voice disorder wherein hyperfunctional laryngeal muscle activity whereas Spasmodic dysphonia (SD) is neurogenic, action-induced focal laryngeal dystonia including several subtype. Both Adductor type spasmodic dysphonia (AdSD) and MTD may be associated with excessive supraglottic contraction and compensation, resulting in a strained voice quality with spastic voice breaks. It makes these two disorders extremely difficult to differentiate based on clinical interpretation alone. Because treatment for AdSD and MTD are quite different, correct diagnosis is important. Clinician should be aware of the specific vocal characteristics of each disease to improve therapeutic outcome.

Medición de la discapacidad vocal en los pacientes con disfonías funcionales / Measurement of the vocal handicap in patients with functional dysphonia

Introducción: La medición de la discapacidad vocal en los pacientes con disfonía funcional es un tema de gran relevancia. Objetivo: Analizar los resultados de dos medidas subjetivas (el índice de discapacidad vocal (VHI) y el índice de calidad de vida (QLI)) y calcular el grado de discapacidad que suponen las disfonías funcionales para los pacientes. Material y método: Sesenta y cinco pacientes diagnosticados de disfonías funcionales contestaron un cuestionario que incluye el índice de discapacidad vocal y el índice de calidad de vida. Resultados: Encontramos un grado importante de discapacidad reflejado por unos valores elevados del VHI (55,74), sus tres subescalas (orgánica (24,82), funcional (19,28) y emocional (11,65) y del QLI (11,42). Discusión: Se realiza una revisión exhaustiva de la literatura, constatando la escasez de estudios sobre la discapacidad que producen los trastronos vocales y se comparan nuestros resultados con los de otros autores. Conclusión: La presencia de disfonías funcionales supone una discapacidad importante a nivel de las actividades sociales y laborales del paciente y un impacto emocional considerable.

Introduction: Functional dysphonia is a major issue. Aim: To analyse the results of two subjective measures (Vocal Handicap Index (VHI) and Quality Life Index (QLI)) and to calculate the impact that functional dysphonias suppose for the patients. Material and Method: 65 patients diagnosed of functional dysphonia answered a questionnaire that includes the Vocal Handicap Index and the Quality Life Index. Results: We found an important degree of handicap indicated by high values of the VHI (55,74), of its three subscales (organic (24,82), functional (19,28) and emotional (11,65)) and of the QLI (11,42). Discussion: We made a wide literature review, noting that there are a few studies of the handicap of voice disorders; and compared our results with those of other authors. Conclusion: The presence of functional dysphonias supposes an important level of handicap in the patient's social and laboral activities and a considerable emotional impact.