title: Distinct phenotypes of speech and voice disorders in Parkinson's disease after subthalamic nucleus deep brain stimulation.
abstract: OBJECTIVE
  To elucidate the phenotypes and pathophysiology of speech and voice disorders in Parkinson's disease (PD) with subthalamic nucleus deep brain stimulation (STN-DBS).
  
  
  METHODS
  We conducted a cross-sectional study on 76 PD patients treated with bilateral STN-DBS (PD-DBS) and 33 medically treated PD patients (PD-Med). Speech and voice functions, electrode positions, motor function and cognitive function were comprehensively assessed. Moreover, speech and voice functions were compared between the on-stimulation and off-stimulation conditions in 42 PD-DBS patients.
  
  
  RESULTS
  Speech and voice disorders in PD-DBS patients were significantly worse than those in PD-Med patients. Factor analysis and subsequent cluster analysis classified PD-DBS patients into five clusters: relatively good speech and voice function type, 25%; stuttering type, 24%; breathy voice type, 16%; strained voice type, 18%; and spastic dysarthria type, 17%. STN-DBS ameliorated voice tremor or low volume; however, it deteriorated the overall speech intelligibility in most patients. Breathy voice did not show significant changes and stuttering exhibited slight improvement after stopping stimulation. In contrast, patients with strained voice type or spastic dysarthria type showed a greater improvement after stopping stimulation. Spastic dysarthria type patients showed speech disorders similar to spastic dysarthria, which is associated with bilateral upper motor neuron involvement. Strained voice type and spastic dysarthria type appeared to be related to current diffusion to the corticobulbar fibres.
  
  
  CONCLUSIONS
  Stuttering and breathy voice can be aggravated by STN-DBS, but are mainly due to aging or PD itself. Strained voice and spastic dysarthria are considered corticobulbar side effects.
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Tsuboi
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Watanabe
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Ohdake
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Noritaka
authors.initials: N
authors.lastname: Yoneyama
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Hara
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Nakamura
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Hazuki
authors.initials: H
authors.lastname: Watanabe
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Jo
authors.initials: J
authors.lastname: Senda
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Atsuta
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Mizuki
authors.initials: M
authors.lastname: Ito
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Hirayama
authors.affiliation: Faculty of Psychological and Physical Science, Aichi-Gakuin University, Aichi, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Department of Otorhinolaryngology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Fujimoto
authors.affiliation: Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Yasukazu
authors.initials: Y
authors.lastname: Kajita
authors.affiliation: Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Wakabayashi
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Gen
authors.initials: G
authors.lastname: Sobue
mesh_terms: D000368:Aged; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D046690:Deep Brain Stimulation; D005260:Female; D006801:Humans; D008297:Male; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D010641:Phenotype; D013064:Speech Disorders / Q000209:etiology*; D020531:Subthalamic Nucleus / Q000503:physiopathology; D014832:Voice Disorders / Q000209:etiology*
keywords: MOVEMENT DISORDERS; PARKINSON'S DISEASE; SPEECH; STEREOTAXIC SURGERY