Multisensory Balance Assessment in Patients with Muscle Tension Dysphonia

Background: Effective vocal production requires a healthy respiratory system, coordinated muscle activity, and proper posture. Since 2010, several studies have been published examining the connections between voice disorders and postural stability, however the literature is limited. The aim of this study is to examine the balance system of patients with muscle tension dysphonia (MTD) using posturography on a multisensory basis.

Method: We evaluated the vestibular systems of patients over 18 years old diagnosed with vocal pathology using virtualis posturography and **VEMP tests**. We used computerized dynamic posturography to temporarily remove or challenge specific parts of the balance system and analyzed the results to identify weaknesses in different components of postural control. We also used VEMP to measure cervical and ocular myogenic potentials. Since vocal pathology may cause tension in the neck muscles, we specifically evaluated **cVEMP** responses, which reflect activity in the neck muscles.

Results: Our study is being conducted as a pilot study, and two individuals diagnosed with MTD have been included. In the Sensory Organization Test, weakness in the visual and vestibular systems was detected. Adaptation Test results were within normal limits, as they maintained balance by developing coping strategies for repetitive movements. In the Motor Control Test, abnormalities in latencies and amplitude scales were observed in both patients. Additionally, cVEMP response could not be obtained from the left side in one patient.

Conclusion: We found that the balance systems of individuals diagnosed with MTD were affected. The data suggests that tension in the SCM muscle impacts the vestibular nerve and saccule function, and that the impairment of the visual and vestibular systems leads to weakness in the balance system. In conclusion, it is believed that the vestibular system is affected in patients with muscle tension dysphonia, although they do not notice this during daily activities.