title: Evaluation of Phonatory Behavior and Voice Quality in Patients with Multiple Sclerosis Treated with Deep Brain Stimulation.
abstract: OBJECTIVE
  The effect of deep brain stimulation (DBS) on phonatory behavior and voice quality in eight patients with multiple sclerosis (MS) was examined instrumentally and perceptually. The acoustic signals of vowel productions obtained from patients (produced with and without stimulation) and from a group of 16 healthy control speakers were analyzed to prove statistically the changes of phonatory behavior and voice quality.
  
  
  METHODS
  This is a randomized study.
  
  
  METHODS
  Firstly, a new parametrization was used to determine phonatory behavior. Secondly, a perceptual evaluation of voice quality of the same speech material was performed.
  
  
  RESULTS
  With stimulation, phonation has a greater tendency to be strained. The results of perceptual evaluation support this strained phonation behavior under stimulation, resulting in a smaller degree of breathiness ratings of all raters. Without stimulation, an impaired and partly disturbed adduction of the vocal folds can be shown. These findings are also supported in the perceptual experiment providing a higher degree of hoarseness ratings of all raters for these signals.
  
  
  CONCLUSIONS
  High-frequency electrical impulses to the thalamus in patients with MS influence the phonatory behavior of their vocal folds. The results suggest the need for long-term monitoring of phonatory behavior during DBS to initiate adequate treatments without delay.
authors.affiliation: Language Science and Technology, Saarland University, Saarbrücken, Germany. Electronic address: puetzer@coli.uni-saarland.de.
authors.forename: Manfred
authors.initials: M
authors.lastname: Pützer
authors.affiliation: Institute for Natural Language Processing, University of Stuttgart, Stuttgart, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wokurek
authors.affiliation: Department of Neurosurgery, Saarland University, Saarbrücken, Germany.
authors.forename: Jean Richard
authors.initials: JR
authors.lastname: Moringlane
mesh_terms: D000328:Adult; D046690:Deep Brain Stimulation / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications / Q000628:therapy*; D010699:Phonation; D014705:Verbal Behavior; D014832:Voice Disorders / Q000209:etiology*; D014833:Voice Quality
keywords: Acoustic analysis; Correlation analysis; Deep brain stimulation; Multiple sclerosis; Perceptual evaluation