Factors Affecting Compliance with Botulinum Toxin Injection in Spasmodic Dysphonia Patients

IntroductIonSpasmodic dysphonia (SD) is a focal laryngeal dystonia where there is involuntary contraction of the adductor or abductor muscles during phonation.Consequently, the voice is strained or has breathy spasms.Occasionally, the patient may have a combination of both, resulting in mixed SD.Adductor spasmodic dysphonia (ADSD) patients have a typical choking voice with spasms prominent on vowels.Thus, sentences with more vowels can highlight this voice disorder. 1 The adductor type is more common than the abductor type, with the former affecting around 80% of people with SD. 2 In the case of abductor spasmodic dysphonia (ABSD), a typical breathy spasm is observed on voiceless consonants which is often accompanied by flaring of the ala nasi. 3 The gold standard treatment for ADSD is considered to be injection of botulinum toxin (BTX) into the affected group of muscles, such 1-