The Relevance of Stroboscopy in Functional Dysphonias¹

Abstract

Objectives: Functional dysphonias are disorders of the voice characterized by sound and efficiency disturbances of the voice without any organic changes of structures being detectable. At present, functional dysphonias are generally subclassified into hyper- and hypofunctional dysphonias in clinical practice. Study Design: The study was designed for a critical evaluation of the relevance of stroboscopy to the diagnostics and classification of functional dysphonias. Methods: 45 patients were examined (27 hyperfunctional, 15 hypofunctional and 3 mixed type) using videostroboscopy. Several stroboscopic parameters were taken into consideration. Three geometrical and three time-dependent parameters were first analyzed in a uni- and multidimensional way, then cluster analyses were performed. Results: We could not confirm the clinical subdivision into hyper- and hypofunctional dysphonias as based on anamnestic data, perceptual evaluation of voice sound, voice profile measurements and videostroboscopy. Quantitative measurements of selected parameters did not correlate with qualitative subjective stroboscopic assessment. In addition to this, it was not possible to identify separate clusters of stroboscopic findings. Conclusions: The results do not deny the clinical relevance of stroboscopy to the diagnostics of functional dysphonias as a very useful tool to exclude organic lesions. However, a reliable subclassification into different types of functional dysphonias was not possible.

Assessment and treatment of musculoskeletal tension in hyperfunctional voice disorders

“…Often cited laryngeal manifestations of dysregulated laryngeal muscle tension include: tight mediolateral glottic and/or supraglottic contraction, anteroposterior glottic and/or supraglottic compression, incomplete glottic closure, posterior glottic chink, and bowing of the vocal folds (Morrison & Rammage, 1994). It should be noted however that researchers have recently challenged the existence of specific laryngoscopic clusters/features believed to uniquely and reliably distinguish MTD from non-dysphonic speakers, and other voice disorder types including spasmodic dysphonia (SD) (Behrman, Dahl, Abramson, & Schutte, 2003;Leonard & Kendall, 1999;Sama, Carding, & Price, 2001;Schneider, Wendler, & Seidner, 2002). According to these investigators, many of the laryngoscopic patterns used to classify MTD such as supraglottic mediolateral and/or anterior-posterior compression, are frequently observed in individuals with normal voices and spasmodic dysphonia, and thus fail to distinguish such individuals from patients with MTD.…”

Stroboscopy Versus High‐Speed Glottography: A Comparative Study

“…Since Schönhärl 1 described stroboscopic visualization of vocal fold vibrations in 1960, this method has been routinely used for diagnostics in neurologic, organic, or functional laryngeal disorders 2–7 . Today in videostroboscopy (VS), the fundamental voice frequency is the trigger signal for the stroboscopic light, a camera is adapted to the endoscope, and the film stored to an analogue or digital tape or hard disk 7 .…”

The Pitch Rise Paradigm: A New Task for Real-Time Endoscopy of Non-Stationary Phonation

“…The conventional visualization technique of vocal fold vibrations is stroboscopy, which allows the investigation of periodic vocal fold oscillations occurring during sustained phonation [3,4] . However, due to violation of the Shannon sampling theorem, stroboscopy is not suitable for the investigation of aperiodic transient vocal fold movements including irregularities or short-time pitch variations [5,6] .…”