Analysis of vocal fold vibration characteristics of spasmodic dysphonia by laryngeal high speed photography combined with glottis area wave

Abstract

Objective: To analyze the characteristics of vocal fold vibration of normal people and patients with spasmodic dysphonia (SD) using laryngeal high speed videoendoscopy combined with glottal area wave analysis. Methods: This prospective study examined twenty healthy subjects (10 males and 10 females), 12 patients with adductor spasmodic dysphonia(AdSD) (2 males,10 females)as AdSD group and 2 patients with abductor spasmodic dysphonia(AbSD) (2 males) as AbSD group. Twelve of healthy subjects (2 males,10 females) were selected as control group according to AdSD group gender match. All the subjects were recruited from the Department of Voice, Zhongshan Hospital, Xiamen University from October 2019 to December 2020. All subjects underwent laryngeal high speed videoendoscopy and 10 vibration periods were selected from each recording and were used to quantitatively analyze the change of glottal area and vocal fold vibration parameters (Speed Quotient (SQ), Open Quotient (OQ) and Close Quotient (CQ)). Results: 1. There were statistically significant differences in SQ, CQ and OQ between males and females in the healthy subjects (t=12.28, 5.59, 5.59, P<0.05). The change of the glottal area during each vibration period in healthy subjects was relatively stable(0.19-0.42). 2. The change of the glottal area during each vibration period in AdSD subjects had larger fluctuations, with the glottal area change index fluctuating in the range of 0.31 to 0.62. The SQ value of the AdSD group was significantly lower than that of control group (t=4.246, P<0.05). There were no significant differences in OQ and CQ between AdSD group and normal group (t=1.064, 1.332, P>0.05); The SQ value of the AbSD group tended to increase compared to normal group. Conclusions: Laryngeal high speed videoendoscopy combined with glottal area wave analysis has a certain reference value in the studying the vibration characteristics of SD patients. SQ has good specificity.