title: Auditory resting-state functional connectivity in tinnitus and modulation with transcranial direct current stimulation.
abstract: CONCLUSIONS
  The functional connectivity (FC) between the right and left auditory cortex is weak in tinnitus patients. Transcranial direct current stimulation (tDCS) over the auditory cortex has potential as a tool to modulate auditory-based FC.
  
  
  OBJECTIVE
  This study investigated the effects of applying tDCS in tinnitus patients, and searched for modulation of brain networks in resting-state functional magnetic resonance imaging (rs-fMRI) through an analysis of FC with the stimulated brain region.
  
  
  METHODS
  Nine male patients with chronic tinnitus and 10 male volunteers with normal hearing were enrolled. The subjects were evaluated with rs-fMRI immediately before and after tDCS. The tinnitus patients filled out the self-evaluation questionnaires designed to measure tinnitus conditions before tDCS treatment and 1 week afterwards.
  
  
  RESULTS
  The FC between the right and left auditory cortex was significantly weaker in tinnitus patients than in controls. After tDCS treatment, in the tinnitus group, the primary auditory cortex showed a reduction in the amount of statistically significant connectivity with the somatosensory area and motor area, but maintained strong significant connectivity (p < 0.005) with the auditory area and insular cortex. In contrast, in the control group, there remained strong significant connectivity between the primary auditory cortex and the somatosensory area, motor area, insular cortex, and auditory area.
authors.affiliation: a 1 National Institute of Sensory Organs, National Tokyo Medical Center , Tokyo, Japan.
authors.forename: Shujiro B
authors.initials: SB
authors.lastname: Minami
authors.affiliation: b 2 Department of Otolaryngology, Head and Neck Surgery, School of Medicine, Keio University , Tokyo, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Oishi
authors.affiliation: b 2 Department of Otolaryngology, Head and Neck Surgery, School of Medicine, Keio University , Tokyo, Japan.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Watabe
authors.affiliation: c 3 Gaienhigashi Clinic , Tokyo, Japan.
authors.forename: Kimiichi
authors.initials: K
authors.lastname: Uno
authors.affiliation: a 1 National Institute of Sensory Organs, National Tokyo Medical Center , Tokyo, Japan.|d 4 Center for Speech and Hearing Disorders, International University of Health and Welfare , Tokyo, Japan.
authors.forename: Kimitaka
authors.initials: K
authors.lastname: Kaga
authors.affiliation: b 2 Department of Otolaryngology, Head and Neck Surgery, School of Medicine, Keio University , Tokyo, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Ogawa
mesh_terms: D000328:Adult; D001303:Auditory Cortex / Q000473:pathology / Q000503:physiopathology*; D001931:Brain Mapping; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000473:pathology / Q000503:physiopathology*; D012146:Rest / Q000502:physiology*; D013003:Somatosensory Cortex / Q000473:pathology / Q000503:physiopathology*; D014012:Tinnitus / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D065908:Transcranial Direct Current Stimulation / Q000379:methods*; D016896:Treatment Outcome
keywords: Magnetic resonance imaging; auditory cortex; hearing; motor cortex; somatosensory cortex