Use of electrical neuromodulation to control adductory spasmodic dysphonia (AdSD) symptoms

Introduction Evidence has been published showing that the superior laryngeal nerve (SLN) paralysis can lead to significant pitch range contractions, vocal fold vibratory phase asymmetry, and acoustic aperiodicity, thus leading to an overall poor vocal quality, suggesting that this nerve may play a significant role in the development of spasmodic dysphonia (SD) symptoms. In 2014, initial results on the potential beneficial effects of unilateral electrostimulation of the thyroarytenoid muscle (TA) on the control of adductory SD (AdSD) were published. Our study aims to evaluate the effects of electrostimulation directly delivered to the internal branch of the SLN (iSLN) on the control of AdSD symptoms

Method Percutaneous electrostimulation was delivered via hooked-wire electrodes 30 min per day for 5 consecutive days. Spasm count (SC), voice strain (VS), phonation effort (PE), voice range profile (VRP), Roughness, Breathiness, Hoarseness (RBH), Maximum Phonation Time (MPT), Voice Handicap Index 9 (VHI-9), and various Quality of Life (QoL) Questionnaires were assessed

Results So far 6 patients (1 male, 5 female) have been enrolled to the study. PE, VS and SC (p=0.031) significantly improved after 5 days of stimulation compared with baseline. All the other assessed parameters showed an improvement, although not statistically significant, possible due to the limited sample size. No adverse event has been reported so far linked to the stimulation

Conclusions Our initial results showed that the iSLN stimulation significantly reduce the SC, VS and PE of the treated patients without causing adverse events. The true effects of the treatment on the VRP and on the QoL will be reassessed in a larger sample size as soon as enough patients are recruited to the study

Poster-PDF A-1364.pdf

MED-EL Elektromedizinische Geräte GmbH

Publication History

Article published online:
13 May 2021