Observation of Laryngeal Postures via High-Speed Videoendoscopy in Adductor Laryngeal Dystonia

Adductor laryngeal dystonia (AdLD) is a neurological disorder characterized by spasms of the laryngeal muscles during speech, resulting in acoustic discontinuities. High-speed videoendoscopy (HSV) has been used to capture supraglottic compression and visual obstructions of the vocal folds during sustained phonation in speakers with AdLD. The purpose of this study was to investigate the co-occurrence of these laryngeal postures via HSV and acoustic discontinuities in speakers with and without AdLD during connected speech.

Speakers with (n = 16) and without (n = 16) AdLD read sentences while undergoing trans nasal laryngoscopy. Microphone and HSV signals were simultaneously recorded. Acoustic discontinuities and laryngeal postures via HSV were independently manually labeled. A multinomial logistic regression was performed to examine the relationship between the presence of acoustic discontinuities-labeled as phonatory break, creak, or frequency shift-and that of view of vocal fold obstruction and supraglottic compression. Additional fixed factors included in the regression model were group (AdLD, control), sex, and the interactions of group × obstruction and group × supraglottic compression.

Factors that were significantly associated with the odds of an acoustic discontinuity included group, vocal fold obstruction, supraglottic compression, and the interaction of group × vocal fold obstruction. There was not a significant interaction effect of group on supraglottic compression events.

These findings suggest that acoustic discontinuities co-occur with supraglottic compression and vocal fold obstructions. Understanding this relationship may lead to more effective voice assessment methods for individuals with AdLD.