Reflux symptoms and vocal characteristics in adults with non-organic voice disorders

Abstract

Laryngopharyngeal reflux (LPR) is a prevalent disorder which can lead to voice disorders, but its diagnosis is difficult. Consequently, various tools and methods have been explored for the diagnosis of LPR. A link may exist between vocal characteristics and reflux symptoms which may improve the diagnosis of LPR. This study’s objective was to investigate the associations between reflux symptoms, acoustic-, perceptual-, and physical vocal characteristics, the glottal function index (GFI) and the voice handicap index (VHI), in adults with non-organic voice disorders. A retrospective cohort explorative research design was employed by investigating, analysing and describing the existing database of an ear, nose and throat specialist (ENT) in the form of administrative data sets, case histories, questionnaires, and patient and stroboscopy reports. Data collection took place at an ENT practice at a private hospital in Gauteng, South Africa. The data of 51 individuals with non-organic voice disorder, aged 18 and older, were included in this study. Comparisons were made between the reflux symptom index (RSI), acoustic characteristics (jitter, shimmer and fundamental frequency (fo), maximum phonation time (MPT), perceptual characteristics (grade of hoarseness, roughness, breathiness, asthenia, strain and instability), physical vocal characteristics, GFI and VHI. Fair correlations were found between RSI and phase closure (rs=0.424; p=0.035), RSI and GFI (rs=0.366; p=0.008), RSI and VHIP (rs=0.302; p=0.035) and between RSI and caffeine intake (rs=0.322); p=0.043). Results indicated that underlying associations exist between reflux symptoms, vocal characteristics, the GFI and the VHI. Used in conjunction, these measurement tools could improve the clinical diagnosis of LPR. The implications of these findings are promising but further research is recommended.