Don't Spaz Out

Question:  A 34 year old woman is referred to your clinic for troubles with her voice.  You notice breathy speech breaks and hypophonia.  Laryngoscopy is consistent with abductor spasmodic dysphonia.  You offer her Botox treatment - what muscle(s) will you treat?  [Answer will be posted with next week's new question]

Answer to last week's question, A Balancing Act (August 17, 2015): 

Endolymphatic sac tumor, likely in the setting of Von Hippel Lindau disease.  VHL is inherited in an autosomal dominant fashion and is characterized by angiomatosis, renal cell carcinoma, and pancreatic masses, among other tumors.