title: Memory networks in tinnitus: a functional brain image study.
abstract: Tinnitus is characterized by the perception of sound in the absence of an external auditory stimulus. The network connectivity of auditory and non-auditory brain structures associated with emotion, memory and attention are functionally altered in debilitating tinnitus. Current studies suggest that tinnitus results from neuroplastic changes in the frontal and limbic temporal regions. The objective of this study was to use Single-Photon Emission Computed Tomography (SPECT) to evaluate changes in the cerebral blood flow in tinnitus patients with normal hearing compared with healthy controls.
  
  
  METHODS
  Twenty tinnitus patients with normal hearing and 17 healthy controls, matched for sex, age and years of education, were subjected to Single Photon Emission Computed Tomography using the radiotracer ethylenedicysteine diethyl ester, labeled with Technetium 99 m (99 mTc-ECD SPECT). The severity of tinnitus was assessed using the "Tinnitus Handicap Inventory" (THI). The images were processed and analyzed using "Statistical Parametric Mapping" (SPM8).
  
  
  RESULTS
  A significant increase in cerebral perfusion in the left parahippocampal gyrus (pFWE <0.05) was observed in patients with tinnitus compared with healthy controls. The average total THI score was 50.8+18.24, classified as moderate tinnitus.
  
  
  CONCLUSIONS
  It was possible to identify significant changes in the limbic system of the brain perfusion in tinnitus patients with normal hearing, suggesting that central mechanisms, not specific to the auditory pathway, are involved in the pathophysiology of symptoms, even in the absence of clinically diagnosed peripheral changes.
authors: Laboratório Interdisciplinar de Neurociências Clínicas (LiNC), Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, Brasil.
authors: Maura Regina
authors: MR
authors: Laureano
authors: Departamento de Otorrinolaringologia e Cirurgia de Cabeça e Pescoço, Universidade Federal de São Paulo, São Paulo, Brasil.
authors: Ektor Tsuneo
authors: ET
authors: Onishi
authors: Laboratório Interdisciplinar de Neurociências Clínicas (LiNC), Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, Brasil ; Instituto do Cérebro - Hospital Israelita Albert Einstein, São Paulo, Brasil.
authors: Rodrigo Affonseca
authors: RA
authors: Bressan
authors: Seção de Medicina Nuclear, Departamento de Radiologia, Universidade Federal de São Paulo, São Paulo, Brasil.
authors: Mario Luiz Vieira
authors: ML
authors: Castiglioni
authors: Laboratório Interdisciplinar de Neurociências Clínicas (LiNC), Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, Brasil ; Instituto do Cérebro - Hospital Israelita Albert Einstein, São Paulo, Brasil.
authors: Ilza Rosa
authors: IR
authors: Batista
authors: Laboratório Interdisciplinar de Neurociências Clínicas (LiNC), Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, Brasil ; Instituto do Cérebro - Hospital Israelita Albert Einstein, São Paulo, Brasil.
authors: Marilia Alves
authors: MA
authors: Reis
authors: Departamento de Fonoaudiologia, Universidade Federal de São Paulo, São Paulo, Brasil.
authors: Michele Vargas
authors: MV
authors: Garcia
authors: Departamento de Fonoaudiologia, Universidade Federal de São Paulo, São Paulo, Brasil.
authors: Adriana Neves
authors: AN
authors: de Andrade
authors: Laboratório Interdisciplinar de Neurociências Clínicas (LiNC), Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, Brasil.
authors: Roberta Ribeiro
authors: RR
authors: de Almeida
authors: Western Australian Centre for Health and Ageing, Centre for Medical Research, University of Western Australia, Perth, Australia.
authors: Griselda J
authors: GJ
authors: Garrido
authors: Laboratório Interdisciplinar de Neurociências Clínicas (LiNC), Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, Brasil.
authors: Andrea Parolin
authors: AP
authors: Jackowski
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D003710:Demography; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008568:Memory; D009415:Nerve Net / Q000503:physiopathology*; D014012:Tinnitus / Q000503:physiopathology*