DOI: http://dx.doi.org/10.18203/issn.2454-5929.ijohns20203562

Study of maximum phonation time and S/Z ratio in laryngeal paralysis

Sudhakar Rao M. S., Keerthi Koripalli, Apoorva P., Vijayalaxmi Malipatil

Abstract


Background: Alterations in human voice occur frequently and patients usually complain of hoarseness of voice. Laryngeal paralysis is an important differential diagnosis in patients complaining change of voice. Because of simplicity and ease, maximum phonation time (MPT) and S/Z ratio have become the most frequently used clinical tools to assess phonatory mechanics. Published research studying analysis of MPT and S/Z ratio in patients with vocal cord paralysis (VCP) is scanty. Hence this study was taken up to study MPT and S/Z ratios in patients with laryngeal paralysis.

Methods: 62 patients with VCP were included in our study. Complete history was taken and examination was done in all patients. VCP was confirmed by indirect laryngoscopic examination. The MPT and S/Z ratios were evaluated in a quiet room. Data was analyzed using IBM SPSS Version 22.

Results: Mean MPT in males with VCP was 6.71±0.54 and in females it was 6.80±2. Mean S/Z ratio in males was 1.69±0.54, in females 1.59±0.35. The difference between laterality of VCP and MPT was statistically highly significant and the difference between laterality of VCP and S/Z ratio was also statistically highly significant. Our study shows no statistically significant difference in MPT and S/Z ratio with respect to age and gender. There was a significant negative correlation between MPT and S/Z ratio.

Conclusions: Irrespective of age and gender MPT and S/Z ratio are simple and effective objective clinical tests to diagnose paralytic laryngeal pathologies. As laryngeal pathology heals on treatment MPT and S/Z ratio are expected to normalize indicating therapeutic progress.


Keywords


Vocal cord paralysis, Maximum phonation time, S/Z ratio

Full Text:

PDF

References


Colton RH, Casper JK, Leonard RJ. Understanding voice problem:A physiological perspective for diagnosis and treatment: Fourth edition. Wolters Kluwer Health Adis (ESP). 2011;494.

Steinecke I, Herzel H. Bifurcations in an asymmetric vocal fold model. J Acoustical Society Am. 1995;97:1874-84.

Belafsky PC, Postima GN, Reulbach TR, Holland BW, Koufman JA. Muscle tension dysphonia as a sign of underlying glottal insufficiency. Otolaryngol-Head Neck Surg. 2002;127:448-51.

Tucker HM. Vocal cord paralysis:etiology and management. Laryngoscope. 1980;90(4):585-90.

Hagen PJ, Deni ville PA. Vocal cord paralysis. Ann Otol Rhinol Laryngol. 1963;72:206.

Goff WF. Vocal cord paralysis analysis of 229 cases. JAMA. 1970;212(8):1378-9.

Titche LL. Causes of recurrent laryngeal nerve nerve paralysis. Arch Otolaryngol-Head Neck Surg. 1976;102:259-61.

Cohen SR, Geller KA, Birns JW, Thompson JW. Laryngeal paralysis in children. Ann Otorhinolaryngol. 1982;91:417-23.

Speyer R, Bogaardt HCA, Passos VL, Roodenburg NPHD, Zumach A, Heijnen MAM, et al. Maximum phonation time: variability and reliability. J Voice. 2010;24:281-4.

Gelfer MP, Pazera JF. Maximum duration of sustained /s/ and /z/ and the s/z ratio with controlled intensity. J Voice. 2006;20:369-79.

Eckel F, Boone DR. The s/z ratio as an indicator of laryngeal pathology. J Speech Hearing Disorders. 1981;46:147-9.

Boone DR. The Voice and Voice Therapy. 1st ed. Englewood Cliffs, NJ: Prentice-Hall; 1971:169.

Benninger MS, Crumley RL, Ford CN, Gould WJ, Hanson DG, Ossoff RH, et al. Evaluation & treatment of the unilaterally paralyzed vocal fold. Otolaryngol-Head Neck Surg. 1994;3:497-508.

Ahmad S, Ajaz M, lateef M. A study of incidence and etiopathology of vocal cord paralysis. Indian J Otolaryngol Head Neck Surg. 2002;54:294-6.

Nerukar N, Tandon S, Kiran K, Joshi A, Gharat P, Bradoo R. Unilateral vocal fold paralysis:an Indian scenario. The Bombay Hospital J. 2006;48(4): 561-7.

Swift AG, Jorger. Vocal cord paralysis. J Laryngol. 1987;101:169-71.

Danies C. Unilateral vocal cord paralysis. Annals of Otol Rhinol Laryngol. 1955; 64(2):487-93.

Ko HC, Lee LA, Li HY, Fang TJ. Etiologic Features in patients with Unilateral Vocal Cord Paralysis in Taiwan. Chang Gung Med J. 2009;32:290-6.

Srirompotong S, Sea-Seow P. The cause and evaluation of Unilateral vocal cord paralysis. Journal of the Medical Association of Thailand. 2001;84:855-8.

Behlau M, Pontes P. Avaliação e Tratamento das Disfonias [Assessment and Treatment of Dysphonias]. São Paulo Lovise.1995;17-37.

Sorenson DN, Parker PA. The voiced/ voiceless phonation time in children with and without Laryngeal pathology. Language Speech Hearing Services Schools.1992;23:163-8.