title: Transcranial magnetic stimulation and extradural electrodes implanted on secondary auditory cortex for tinnitus suppression.
abstract: OBJECTIVE
  Tinnitus is a prevalent symptom, with clinical, pathophysiological, and treatment features analogous to pain. Noninvasive transcranial magnetic stimulation (TMS) and intracranial auditory cortex stimulation (ACS) via implanted electrodes into the primary or overlying the secondary auditory cortex have been developed to treat severe cases of intractable tinnitus.
  
  
  METHODS
  A series of 43 patients who benefited transiently from 2 separate placebo-controlled TMS sessions underwent implantation of auditory cortex electrodes. Targeting was based on blood oxygen level-dependent activation evoked by tinnitus-matched sound, using functional MR imaging-guided neuronavigation.
  
  
  RESULTS
  Thirty-seven percent of the patients responded to ACS with tonic stimulation. Of the 63% who were nonresponders, half benefited from burst stimulation. In total, 33% remained unaffected by the ACS. The average tinnitus reduction was 53% for the entire group. Burst stimulation was capable of suppressing tinnitus in more patients and was better than tonic stimulation, especially for noise-like tinnitus. For pure tone tinnitus, there were no differences between the 2 stimulation designs. The average pure tone tinnitus improvement was 71% versus 37% for noise-like tinnitus and 29% for a combination of both pure tone and noise-like tinnitus. Transcranial magnetic stimulation did not predict response to ACS, but in ACS responders, a correlation (r = 0.38) between the amount of TMS and ACS existed. A patient's sex, age, or tinnitus duration did not influence treatment outcome.
  
  
  CONCLUSIONS
  Intracranial ACS might become a valuable treatment option for severe intractable tinnitus. Better understanding of the pathophysiological mechanisms of tinnitus, predictive functional imaging tests, new stimulation designs, and other stimulation targets are needed to improve ACS results.
authors.affiliation: Brai2n, University Hospital Antwerp, Belgium.
authors.forename: Dirk
authors.initials: D
authors.lastname: De Ridder
authors.forename: Sven
authors.initials: S
authors.lastname: Vanneste
authors.forename: Silvia
authors.initials: S
authors.lastname: Kovacs
authors.forename: Stefan
authors.initials: S
authors.lastname: Sunaert
authors.forename: Tomas
authors.initials: T
authors.lastname: Menovsky
authors.forename: Paul
authors.initials: P
authors.lastname: van de Heyning
authors.forename: Aage
authors.initials: A
authors.lastname: Moller
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000704:Analysis of Variance; D001303:Auditory Cortex / Q000503:physiopathology*; D004567:Electrodes, Implanted / Q000009:adverse effects; D004569:Electroencephalography; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods; D025321:Surgery, Computer-Assisted / Q000379:methods; D014012:Tinnitus / Q000503:physiopathology / Q000601:surgery / Q000628:therapy*; D050781:Transcranial Magnetic Stimulation / Q000009:adverse effects; D016896:Treatment Outcome