Evaluation of transnasal videoendoscopic-guided botulinum toxin injection in patients with adductor spasmodic dysphonia

<b>Introduction:</b> Adductor spasmodic dysphonia (ASD) is a focal laryngeal dystonia characterized by involuntary vocal fold spasms, resulting in a strained and effortful voice. Botulinum toxin injection is the standard treatment, typically performed using electromyography-guided techniques. <br><br><b>Aim: </b>This study evaluates the efficacy of office-based transnasal videoendoscopic-guided botulinum toxin injection as an alternative to electromyography-guided percutaneous injection in patients with adductor spasmodic dysphonia (ASD). <br><br><b>Methods:</b> A cohort of patients with ASD underwent transnasal laryngeal injections of botulinum toxin using a flexible video endoscope. Local anesthesia was administered, and a flexible needle was used to inject botulinum toxin into the vocal and/or vestibular folds. Phonation was assessed before and after the procedure. <br><br><b>Results:</b> Twenty-seven patients with ASD showed significant improvements in VHI-10 (Voice Handicap Index-10) and VRQOL (Voice Related Quality of Life) scores post-injection. Additionally, the GRBAS scale scores improved after the procedure. <br><br><b>Conclusions:</b> Office-based transnasal videoendoscopic-guided botulinum toxin injection is a reliable and straightforward technique for treating ASD. It can be performed without electromyography, making it accessible for all laryngologists.