Efficacy of Botulinum Toxin Injection into Posterior Cricoarytenoid Muscles for the Management of Aspiration in Bilateral Adductor Vocal Fold Paralysis: A Case Series

Objective: Bilateral adductor vocal fold paralysis (BAVCP) is a rare condition causing dysphonia and aspiration. Botulinum toxin (BTX) injection has been proposed as a reversible bridging therapy for temporary and permanent cases. This study evaluates voice and swallowing outcomes after BTX injection into the posterior cricoarytenoid (PCA) muscle in patients with BAVCP. Methods: Ten patients (nine female, one male; age 19–69 years) with BAVCP underwent PCA BTX injection. Functional outcomes included Maximum Phonation Time (MPT), Penetration-Aspiration Scale (PAS), and vocal fold gap measured by flexible laryngoscopy. Assessments were performed pre-injection and at 4 weeks postinjection. Results: Mean PAS score improved from 7.0 (6–8) pre-injection to 4.1 (2–6) postinjection (P = 0.0056). Mean MPT increased from 1.4 seconds (1–2) to 4.1 seconds (3.7–4.9) (P = 0.0057). Glottic gap decreased from 8 mm (7–9) to 4 mm (3–5) (P = 0.0019). All patients experienced swallowing improvement; dyspnea was not observed. Temporary paralysis cases required a single injection, while permanent cases needed repeated injections every 3–5 months. Conclusions: PCA BTX injection in BAVCP is a safe, reversible method that improves voice and swallowing. It can serve as a bridging therapy in temporary paralysis and a functional-preserving treatment in permanent cases.