title: Hypophonia in Parkinson's disease: neural correlates of voice treatment revealed by PET.
abstract: OBJECTIVE
  To investigate the neural correlates of hypophonia in individuals with idiopathic PD (IPD) before and after voice treatment with the Lee Silverman Voice Treatment method (VT) using (15)O-H(2)O PET.
  
  
  METHODS
  Regional cerebral blood flow (rCBF) changes associated with overt speech-motor tasks relative to the resting state were measured in the IPD subjects before and after VT, and in a group of healthy control volunteers.
  
  
  RESULTS
  Behavioral measures of voice loudness significantly improved following treatment. Before VT, patients had strong speech-related activations in motor and premotor cortex (M1-mouth, supplementary motor cortex [SMA], and inferior lateral premotor cortex [ILPm]), which were significantly reduced post-VT. Similar to the post-treatment session, premotor activations were absent (SMA) or below statistical threshold (M1-mouth) in the healthy control group. In addition, following VT treatment, significant right-sided activations were present in anterior insular cortex, caudate head, putamen, and dorsolateral prefrontal cortex (DLPFC). Finally, the VT-induced neural changes were not present with transient experimenter-cued increases of loudness in VT-untreated patients.
  
  
  CONCLUSIONS
  Effective improvement of IPD hypophonia following voice treatment with VT was accompanied by a reduction of cortical motor-premotor activations, resembling the functional pattern observed in healthy volunteers and suggesting normalization, and additional recruitment of right anterior insula, caudate head, putamen, and DLPFC. This treatment-dependent functional reorganization suggests a shift from an abnormally effortful (premotor cortex) to a more automatic (basal ganglia, anterior insula) implementation of speech-motor actions.
authors.affiliation: Research Imaging Center, Department of Medicine, University of Texas Health Science Center at San Antonio, TX, USA. mario.liotti@nottingham.ac.uk
authors.forename: M
authors.initials: M
authors.lastname: Liotti
authors.forename: L O
authors.initials: LO
authors.lastname: Ramig
authors.forename: D
authors.initials: D
authors.lastname: Vogel
authors.forename: P
authors.initials: P
authors.lastname: New
authors.forename: C I
authors.initials: CI
authors.lastname: Cook
authors.forename: R J
authors.initials: RJ
authors.lastname: Ingham
authors.forename: J C
authors.initials: JC
authors.lastname: Ingham
authors.forename: P T
authors.initials: PT
authors.lastname: Fox
mesh_terms: D000368:Aged; D001479:Basal Ganglia / Q000000981:diagnostic imaging / Q000503:physiopathology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D010699:Phonation; D011932:Reading; D012016:Reference Values; D014055:Tomography, Emission-Computed; D016896:Treatment Outcome; D014705:Verbal Behavior; D014832:Voice Disorders / Q000150:complications / Q000175:diagnosis* / Q000534:rehabilitation*; D014834:Voice Training