Botulinum Toxin Of Type A Treatment For Spasmodic Dysphonia

BackgroundAs an agnogenic disease, adductor spasmodic dysphonia is a local muscle tension disorder. Research of this disease has continued for more than 50 years, and botulinum toxin of type A is widely used now. But the etiology, diagnosis and treatment are still in the exploratory stage. There are no guidelines or standards to consult.ObjectiveWith review of 28 patients of adductor spasmodic dysphonia, this article focuses on the effectiveness of injection into bilateral thyroarytenoid muscle with botulinum toxin of type A.MethodsA retrospective study was finished with 28 patients who had injected botulinum toxin of type A from March 2003 to August 2014 (during 11 years) in Hopital Larrey, Toulouse, France. All patients were diagnosed as adductor spasmotic dysphonia. We demanded the patients to finish self rating and we recorded their voice. All voice segments were sorted randomly. Then two independent speech pathologists analyzed and scaled these segments. Make the first visit’s self rating and voice scores as the baseline. We compared these values after the treatment at 1 week,4 weeks,8 weeks and 16 weeks of follow up. All the statistical analysis was completed by SPSS 19.0.ResultsExcept 1 patient hadn’t any change after 1 week,4 weeks,8 weeks and 16 weeks, the remaining 27 patients showed improvement in different degree. The differences were statistically significant (P<0.01). The spasms and breaks were improved most obviously after 4 weeks. The most remarkable change of tension, tremor and volume happened 1 week after injection. There was no appearance of overdosing.1 patient had transitory vertigo,1 patient occurred local anterior cervical pain,4 patients suffered breathiness,4 patients appeared swallowing dysfunction and 10 patients presented phonation change. All the symptoms were mild and self-healing without any treatment.ConclusionBoNT-A is an effective treatment for some patients in ADSD, injection into bilateral thyroarytehoid muscle with 40U in total (20U per side) is safe and effective.