Coagulation of posterior cricoarytenoid muscles for abduction spasmodic dysphonia.

[INTRODUCTION] Spasmodic dysphonia (SD), a form of focal dystonia, has been defined as a neurogenic, task-specific disorder characterized by abrupt spasms of intrinsic laryngeal muscles that result in phonatory breaks. There are three classic types of SD: adductor SD, abductor (ABSD) and mixed SD. Compared with the more common adductor form, treatment of ABSD with botulinum toxin injection is related to a shorter efficacy and improvement in only about 70% of patients [Blitzer et al. in Laryngoscope 108:1435-1441, 1998]. Moreover, due to the possible loss of efficacy over time or patient refusal for repeated injections, surgical solutions for permanent or at least long-term results must be considered.

[METHOD] The surgical technique we propose is based on transoral bilateral posterior cricoarytenoid muscle (PCA) coagulation by radiofrequency (Celon, pro surg 250-T30, Olympus, Germany, 10 W, in 3 spots, each side) under a microscope or rigid scope control. The procedure is performed in two sessions distant of 2-3 weeks to avoid the risk of bilateral vocal fold temporary paralysis in adduction. A 52-year-old female patient with no audible voicing, resistant to botulinum toxin and after failure of relaxation thyroplasty type III according to lssihki [Saito et al. in Case Rep Otolaryngol 2018:4280381, 2018] showed an improvement of the Voice Handicap Index (VHI-10) from 35/40 to 19/40. The patient was rated G2R3B2A1S2 according to GRABS scale.

[CONCLUSION] PCA coagulation for ABSD is a safe and reusable surgical option. It is less invasive than other techniques described before. To the best of our knowledge, this technique was never reported before in this type of SD.