Usefulness of Water-Resistance Straw Phonation in Discrimination of Adductor-Type Spasmodic Dysphonia and Muscle Tension Dysphonia

Abstract

Objectives: Although Adductor-type spasmodic dysphonia (AdSD) and Muscle tension dysphonia (MTD) show similar phonetic symptoms, the causes and treatment methods are different. Therefore, discrimination is necessary for the proper treatment of the two diseases. The purpose of this study is to investigate the usefulness of Water-resistance straw phonation (WSP) as a diagnostic therapy for the differentiation of AdSD and MTD. To that end, Both patients with AdSD and MTD performed WSP, and their voices was measured before and after diagnostic therapy.Methods: A total of 27 (18 MTD, 9 AdSD) individuals participated in this study. The MTD group (4 male, 14 female) mean age was 30.01 years and the AdSD (2 male, 7 female) group mean age was 31.03. Both groups were treated with diagnostic therapy using WSP which took approximately 90 seconds. The acoustic analysis and auditory–perceptual assessment were completed after diagnostic therapy.Results: The MTD group was significantly lower in Jitter Percent (Jitter) (p= .003), Pitch Perturbation Quotient (PPQ) (p= .007), Fundamental Frequency Variation (vF0) (p= .004), Shimmer Percent (Shimmer) (p= .010), Amplitude Perturbation Quotient (APQ) (p= .012), Peak to Peak Amplitude Variation (vAm) (p= .005) and auditory–perceptual grade (p= .007). However, the AdSD group was not significantly different for all variables after performing the WSP.Conclusion: WSP is one of the methods that relieve laryngeal hypertension. In this study, the voice improvement of the MTD group after diagnostic therapy using WSP meant that the laryngeal hypertension was relieved. This change indicates a high probability of MTD as opposed to AdSD. Whereas, no improvement or worsening of the voice problem suggests neither the probability of MTD nor no confirmation of AdSD. Therefore, a diagnostic therapy using WSP may be useful as one of the evaluation methods for discrimination between AdSD and MTD.