Diagnosis and management with botulinum toxin in 11 cases of laryngeal synkinesis

Laryngeal synkinesis is a vocal fold movement disorder produced by a misdirected reinnervation after a recurrent laryngeal nerve injury. Its symptoms differ greatly between patients, requiring diverse therapeutical approaches. We aim to describe our experience in the diagnosis and treatment of different laryngeal synkinesis presentations. 11 patients diagnosed between 2011 and 2014 in a tertiary referral center with laryngeal synkinesis confirmed by laryngeal electromyography were included in our study. All medical records and laryngoscopic and electromyographic data were reviewed retrospectively. Four patients had previous unilateral vocal fold palsy and seven had a bilateral palsy with different degrees of clinical involvement. All of them showed paradoxical movements during inhalation in videofibrolaryngoscopic examination. Laryngeal electromyography confirmed the diagnosis of laryngeal synkinesis. Dyspnea was the main presentation symptom. Three patients with mild symptoms were not treated. Patients with unilateral vocal fold immobility were successfully treated with periodic botulinum toxin injections. Patients with bilateral immobility had a good initial response to botulinum toxin, although in some of them, a posterior cordectomy had to be finally performed. In conclusion, laryngeal synkinesis is a heterogeneous clinic entity that appears in patients with unilateral or bilateral vocal fold paralysis. Videofibrolaryngoscopy and laryngeal electromyography are essential to a correct diagnosis. Botulinum toxin injections are the main treatment for symptomatic cases, even if in bilateral palsy cases more aggressive treatments are often required.