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Maximum Glottal Angle in Patients with Functional and Organic Laryngeal Pathologies Compared to Healthy Controls

Gold, Katherine Rose (2022) Maximum Glottal Angle in Patients with Functional and Organic Laryngeal Pathologies Compared to Healthy Controls. Master's Thesis, University of Pittsburgh. (Unpublished)

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Objectives: Currently, practitioners rely on visual judgments of glottal angle (viewed endoscopically) to determine whether maximum abduction is within normal limits on a repeated sniff maneuver. Investigators have previously examined maximum glottal angle of healthy individuals and patients with unilateral vocal fold paralysis during an “ee-sniff” maneuver. Others have compared maximum glottal angle in healthy individuals to those with paradoxical vocal fold movement disorder during inspiration at rest and during exercise. However, no one has yet systematically compared groups of patients with various voice and laryngeal breathing disorders to vocally healthy control participants to characterize the nature of differences in vocal fold mobility across groups.
Design: Via retrospective analysis of laryngoscopic exam videos obtained from a specialty voice center, we measured glottal angle in five groups: vocally healthy controls and patients with spasmodic dysphonia/essential tremor (SD/ET), lesions, atrophy, paradoxical vocal fold motion disorder (PVFMD), or muscle tension dysphonia (MTD). From each laryngoscopic exam video, we calculated maximum glottal angle (GAMAX) and average glottal angle (GAAVG) during three subsequent sniff maneuvers. Individual disorder groups (MTD, PVFMD, SD/ET, atrophy, lesion) and broader disorder types (functional and organic) were compared to healthy controls using simple linear regression analyses.
Results: No significant difference in vocal fold mobility was found between healthy individuals and individuals within a disorder subgroup or broader disorder type for neither GAMAX nor GAAVG. Follow-up analyses revealed statistically significant differences in variability magnitude of maximum glottal angle in both PVFMD (6.2° more variability (p<0.001)) and SD/ET (5.8° more variability (p<0.001)) compared to healthy controls.
Conclusion: Neither average nor maximum glottal angle derived from a sniff maneuver were useful in differentiating patients with voice disorders. However, the magnitude of glottal angle variance in SD/ET and PVFMD might be a useful objective measurement for laryngoscopy. Future research should probe the sensitivity of this measurement for identification and differential diagnosis of these patient populations in clinical or research settings.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Gold, Katherine Rosekrg58@pitt.edukrg58
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairHelou, Leahlbh7@pitt.edulbh7
Committee MemberRousseau,
Date: 13 June 2022
Date Type: Publication
Defense Date: 9 March 2022
Approval Date: 13 June 2022
Submission Date: 24 March 2022
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Number of Pages: 45
Institution: University of Pittsburgh
Schools and Programs: School of Health and Rehabilitation Sciences > Communication Science and Disorders
Degree: MS - Master of Science
Thesis Type: Master's Thesis
Refereed: Yes
Uncontrolled Keywords: glottal angle, organic voice disorder, functional voice disorder, spasmodic dysphonia, paradoxical vocal fold movement disorder
Date Deposited: 14 Jun 2022 01:59
Last Modified: 19 May 2023 13:49


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