title: Value of Laryngeal Electromyography in Spasmodic Dysphonia Diagnosis and Therapy.
abstract: OBJECTIVE
  To investigate the role of laryngeal electromyography (LEMG) in the diagnosis and treatment of spasmodic dysphonia (SD).
  
  
  METHODS
  The clinical manifestations, characteristics of motor unit potentials (MUPs), recruitment potentials, and laryngeal nerve evoked potentials (EPs) in LEMG, as well as the changes after botulinum toxin (BTX) treatment, were analyzed in 39 patients with adductor SD.
  
  
  RESULTS
  The main clinical manifestations were a strained voice and phonation interruptions; in addition, the patients displayed hyper-adducted vocal folds during phonation. LEMG revealed significantly increased amplitudes of the thyroarytenoid muscle MUPs. The recruitment potentials were in a dense bunch, discharging full interference patterns with significantly increased amplitudes; the mean and maximum amplitude of recruitment potentials were 3090 μV and 5000 μV, respectively. The amplitude of EPs of thyroarytenoid muscle increased significantly; the mean and maximum amplitudes were 10.3 mV and 26.3 mV, respectively. After BTX was injected, the LEMG revealed denervation changes, and the EPs weakened or disappeared in the injected muscle.
  
  
  CONCLUSIONS
  SD could be diagnosed, and the therapeutic efficacy of SD treatments could be evaluated based on clinical characteristics combined with LEMG characteristics. The increased amplitudes of the recruitment potentials and EPs of the thyroarytenoid muscle were the characteristic indexes. After BTX was injected, denervated potential characteristics appeared in the muscles.
authors: Department of Otorhinolaryngology-Head Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors: Qingwen
authors: Q
authors: Yang
authors: Department of Otorhinolaryngology-Head Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China entwen@trhos.com.
authors: Wen
authors: W
authors: Xu
authors: Department of Otorhinolaryngology-Head Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors: Yun
authors: Y
authors: Li
authors: Department of Otorhinolaryngology-Head Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors: Liyu
authors: L
authors: Cheng
mesh_terms: D000328:Adult; D000368:Aged; D001905:Botulinum Toxins / Q000627:therapeutic use*; D055154:Dysphonia / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D004576:Electromyography / Q000379:methods*; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007821:Laryngeal Muscles / Q000294:innervation / Q000503:physiopathology*; D007823:Laryngeal Nerves / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D009498:Neurotoxins / Q000627:therapeutic use; D015203:Reproducibility of Results; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D009498:Neurotoxins; D001905:Botulinum Toxins
keywords: laryngeal electromyography; spasmodic dysphonia