Videostroboscopy Versus High-Speed Videoendoscopy: Factors Influencing Ratings of Laryngeal Oscillation

The purpose of this study was to determine whether patient voice-related diagnosis, severity of dysphonia, and rater's experience influence the relationship between laryngeal oscillation ratings made from videostroboscopic and high-speed videoendoscopic (HSV) exams.

Stroboscopy and HSV exams from 15 patients with adductor spasmodic dysphonia (ADSD) and 15 with benign vocal fold lesions were rated for laryngeal oscillation and closure by 10 licensed speech-language pathologists (SLPs). Raters were divided into low- (< 5 years) and high-experience (> 5 years) groups. Ratings of vocal fold amplitude, mucosal wave, periodicity, phase symmetry, nonvibrating portion of the vocal fold, and glottal closure were examined using an online form adapted from the Voice Vibratory Assessment of Laryngeal Imaging (VALI).

Stroboscopy and HSV ratings were more strongly positively correlated for patients with benign vocal fold lesions (r between .43 and .75) than for those with ADSD (r between .40 and .68). Differences between stroboscopy and HSV exams were significantly greater for ratings of amplitude, mucosal wave, and periodicity in patients with ADSD than for patients with benign vocal fold lesions. Raters with < 5 years of experience showed significantly greater differences between stroboscopy and HSV ratings of amplitude and nonvibrating portion of the vocal fold for patients with ADSD only. Significantly greater differences between ratings of periodicity and phase symmetry were observed in patients with more severe dysphonia.

Differences in laryngeal ratings made between HSV and stroboscopy exams may be influenced by patient diagnosis, severity of dysphonia, and rater experience. Future study is warranted to determine how the differences observed influence clinical diagnosis and outcomes.