Laryngeal Vibrotactile Stimulation as a Non-Invasive Adjunctive Treatment for Spasmodic Dysphonia: A Preliminary Study

Abstract

Spasmodic dysphonia (SD) is a debilitating condition characterized by involuntary closure of the vocal folds, leading to strained and choked speech. Current treatment options have limitations and require repeated interventions. However, recent studies have shown that high-frequency peripheral somatosensory stimulation is able to modulate neuronal discharge at the somatomotor cortical level and positively influence motor output and therefore SD symptoms. This study investigates the potential of laryngeal vibrotactile stimulation (VTS) as a non-invasive treatment for SD. A custom device was used to apply high-frequency vibrations to the larynx of three female patients with adductor-type SD. The patients underwent VTS treatment once a day for four weeks. Four parameters were used to assess vocal quality: Acoustic Voice Quality Index (AVQI), Cepstral Peak Prominence Smoothed (CPPS), number of voice interruptions (Voice Breaks), and perceptual evaluation using the GIRBAS scale. The results showed improvements in all parameters following VTS treatment, indicating enhanced phonatory function quality and speech stability. These findings highlight the potential of VTS to alleviate symptoms in individuals diagnosed with adductor-type SD.