Dysphonia Characteristics and Vowel Impairment in Relation to Neurological Status in Patients with Multiple Sclerosis.

PURPOSE: In this study, we attempted to assess the phonation and articulation subsystem changes in patients with multiple sclerosis compared to healthy individuals using Dysphonia Severity Index and Formant Centralization Ratio with the aim of evaluating the correlation between these two indexes with neurological status. MATERIALS AND METHODS: A sample of 47 patients with multiple sclerosis and 20 healthy speakers were evaluated. Patients' disease duration and disability were monitored by a neurologist. Dysphonia Severity Index and Formant Centralization Ratio scores were computed for each individual. Acoustic analysis was performed by Praat software; the statistical analysis was run using SPSS 21. To compare multiple sclerosis patients with the control group, Mann-Whitney U test was used for non-normal data and independent-samples t test for normal data. Also a logistic regression was used to compare the data. Correlation between acoustic characteristics and neurological status was verified using Spearman correlation coefficient and linear regression was performed to evaluate the simultaneous effects of neurological data. RESULTS: Statistical analysis revealed that a significant difference existed between multiple sclerosis and healthy participants. Formant Centralization Ratio had a significant correlation with disease severity. CONCLUSION: Multiple sclerosis patients would be differentiated from healthy individuals by their phonation and articulatory features. Scores of these two indexes can be considered as appropriate criteria for onset of the speech problems in multiple sclerosis. Also, articulation subsystem changes might be useful signs for the progression of the disease.

Translation and Validation of the Voice Catastrophization Index for Persian-Speaking Patients with Dysphonia.

PURPOSE: Catastrophization refers to the cognitive distortion that is experienced by patients with several diseases who suffer from pain. There is some evidence that catastrophization may be found in patients with voice disorders. The Voice Catastrophization Index (VCI) was developed in English to measure catastrophization in patients with dysphonia. The goal of this research was to translate and validate the Persian version of the VCI (P-VCI) for use with Persian-speaking people in Iran and elsewhere. METHODS: This was a prospective and cross-sectional study. First, the questionnaire was translated, then its various psychometric properties were investigated. RESULTS: There was a significant difference in mean P-VCI score between participants with and without dysphonia (p < 0.001). Test-retest reliability for the total score of P-VCI was excellent (ICC = 0.94, p < 0.001), as was its internal consistency, as determined by Cronbach's alpha coefficient (α = 0.956). Confirmatory factor analysis revealed that some of the indices show a good fit for the 3-subscale model. There was a moderate correlation in criterion-related validity between the P-VCI and Voice Activity Participation Profile - Persian version (r = 0.644, p < 0.001). CONCLUSIONS: The translated test exhibited satisfactory psychometric properties. The P-VCI is a valid and reliable tool for the assessment of catastrophization in persons with voice disorders.