[Use of botulinum toxin in the treatment of laryngeal dystonia (spasmodic dysphonia): preliminary study of twelve patients].

Laryngeal dystonia (spasmodic dysphonia) is a movement disorder characterized by involuntary contractions of laryngeal muscles involved with vocalization. The introduction of botulinum toxin in the treatment of laryngeal dystonia had a major clinical impact due to the striking improvement of symptoms. We report the preliminary results of therapeutical use of botulinum toxin in the treatment of twelve patients with laryngeal dystonia. After an extensive clinical evaluation, the patients underwent a videostroboscopic exam for diagnostic confirmation. Botulinum toxin was injected in the cricothyreoid membrane, directed towards the thyreoaritenoid muscle, with the aid of eletromyography needles. Most of patients who underwent botulinum toxin injection had a significant improvement of their symptoms (83%), with effects lasting for four months in average and without important side effects.