[Indications for botulinum toxin in laryngectomy].

The botulinum toxin is a highly potent neurotoxin, used since several years in the treatment of the focal musculary dystonias. We define the laryngeal dystonia as a clinical entity, which is represented by a spasmodic dysphonia or an inspiratory dyspnea without dysphonia, related to a specific dystonia of the thyroarytenoid muscles. The laryngeal functional exploration (i.e. fibroscopy, videostroboscopy, acoustic analysis, computerized voice analysis), the neurological and electrophysiological assessment allow to make diagnosis and evaluation of the therapeutical results of this rare laryngeal neurologic disease which was relatively misunderstood until now. There are several clinical types of spasmodic dysphonia: adductor form (with a jerky voice, pitch beaks, vocal arrests and pneumophonatory incoordination); abductor form (with a breathy voice of very low intensity) and mixed types which can be difficult to identify. Since 1989, we have treated 55 laryngeal dystonias with local intra-muscular botulinum toxin injection: 48 spasmodic dysphonia and 7 inspiratory dyspnea without dysphonia, with hyperactivity of the thyroaryténoïd muscles. We present our therapeutical protocol and results which are good in 87% of cases.