Electrostimulation of the neck portion corresponding to the thyroarytenoid-lateral cricoarytenoid (TA-LCA) complex for the treatment of spasmodic dysphonia (SD) and voice tremor (VT)

Introduction A 2013 review by Miller et al. reported electrostimulation has been assessed as a potential therapeutic tool for different types of laryngeal dystonia, including spasmodic dysphonia (SD) and voice tremor (VT), for about 40 years. The main problems, namely the characterization of the stimulation protocol and definition of outcome measures used as pass/fail criteria for the respective studies, were exacerbated by the lack of standardized diagnostic and therapeutic protocols for these conditions. We have developed a surface electrostimulation protocol applicable by SD and VT patients for daily home sessions.

Materials and Methods We included 15 patients foreseeing a 6-month use of an external electrostimulator with surface electrodes applied on the TA-LCA complex. Stimulation was performed for 30 min twice a day, parameters were adjusted at each session. Pre-stimulation strain and tremor score, spasm count, voice quality and quality of life questionnaires were assessed and then compared with intra- and post-stimulation results at intervals between 15–60 days.

Results All patients completed the study. VT patients used higher stimulation frequencies than SD patients, all ranging between 40 and 100 Hz with a mean pulse width of 0.2 ms and average amplitudes between 2 and 15 mA. Strain and tremor score, spasm count, maximum phonation time improved over treatment, with patients reporting better results when the interval between the 2 daily sessions was about 6h and worse when longer. Significant voice quality improvements required on average about 1 month.

Conclusions The correct configuration and positioning of the surface electrodes plays a major part in ensuring better results along with the choice of the interval between the 2 daily sessions.

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Artikel online veröffentlicht:
24. Mai 2022