Is Computerized Dynamic Posturography Analysis in Dysphonic Patients Different after Vocal Rehabilitation Treatment? A Longitudinal Study

Abstract

Aim: Vocal pathology and vocal rehabilitation may influence posture, and changes in postural pattern can influence the mechanisms of vocal production. This study aimed to evaluate the postural pattern in subjects with unilateral vocal fold paresis/paralysis before and after speech rehabilitation, using computerized dynamic posturography (CDP). Materials and methods: This is a prospective cohort study, studying the posture pattern of 16 patients affected by dysphonia, caused by unilateral vocal fold paresis/paralysis, never treated with speech therapy, and by CDP before and after vocal rehabilitation. Each patient underwent videolaryngostroboscopy, acoustic voice analysis, aerodynamic evaluation, GRBAS scale, and voice handicap index questionnaire. Fifteen healthy volunteers were also submitted to a posturographic analysis as a control group. Results: All patients showed an improvement in voice quality after vocal training. The auditory-perceptual evaluation with the GRBAS scale showed a decrease in all parameters for both vowel (/a/, /i/, /e/) and spontaneous speech (p < 0.001 for all). Furthermore, the acoustic analysis showed an improvement in fundamental frequency, shimmer, harmonic-to-noise ratio, and normalized noise energy. Posturographic results showed an improvement in equilibrium score; conditions 1, 2, 4, 5, and 6; and composite score. Strategic analysis results showed an improvement in conditions 2, 5, and 6. Conclusion: Posturographic analysis showed a significant difference in the proprioceptive, visual, and vestibular component of posture, after voice therapy. These results confirmed an improvement in the postural performance of dysphonic patients after a successful voice treatment. Clinical significance: The results of this study indicate that modifications of voice production techniques lead to objective and measurable postural changes in dynamic posturographic analysis.