High-Resolution fMRI of Auditory Cortical Map Changes in Unilateral Hearing Loss and Tinnitus.
Animal models of hearing loss and tinnitus observe pathological neural activity in the tonotopic frequency maps of the primary auditory cortex. Here, we applied ultra high-field fMRI at 7 T to test whether human patients with unilateral hearing loss and tinnitus also show altered functional activity in the primary auditory cortex. The high spatial resolution afforded by 7 T imaging allowed tonotopic mapping of primary auditory cortex on an individual subject basis. Eleven patients with unilateral hearing loss and tinnitus were compared to normal-hearing controls. Patients showed an over-representation and hyperactivity in a region of the cortical map corresponding to low frequencies sounds, irrespective of the hearing loss and tinnitus range, which in most cases affected higher frequencies. This finding of hyperactivity in low frequency map regions, irrespective of hearing loss range, is consistent with some previous studies in animal models and corroborates a previous study of human tinnitus. Thus these findings contribute to accumulating evidence that gross cortical tonotopic map reorganization is not a causal factor of tinnitus.
Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland. naghmeh.ghazaleh@epfl.ch.|Department of Radiology and Medical Informatics, University of Geneva, Geneva, Switzerland. naghmeh.ghazaleh@epfl.ch.
Naghmeh
http://orcid.org/0000-0002-5078-7281
N
Ghazaleh
Spinoza Centre for Neuroimaging, Royal Netherlands Academy for Arts and Sciences, Amsterdam, Netherlands.|Center for Biomedical Imaging, University of Lausanne, Lausanne, Switzerland.
Wietske van der
WV
Zwaag
Service of Neuropsychology and Neurorehabilitation, Department of Clinical Neurosciences, Lausanne University Hospital, Lausanne, Switzerland.
Stephanie
S
Clarke
Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.|Department of Radiology and Medical Informatics, University of Geneva, Geneva, Switzerland.
Dimitri Van De
DV
Ville
Department of Otorhinolaryngology, Head and Neck Surgery, Lausanne University Hospital, Lausanne, Switzerland.
Raphael
R
Maire
Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.|Neuroimaging Research Lab (LREN), Department of Clinical Neurosciences, Lausanne University Hospital, Lausanne, Switzerland.
Melissa
M
Saenz
D000328:Adult; D001303:Auditory Cortex / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001931:Brain Mapping / Q000379:methods; D005260:Female; D046088:Hearing Loss, Unilateral / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D014012:Tinnitus / Q000000981:diagnostic imaging* / Q000503:physiopathology
Neural plasticity; Primary auditory cortex; Tinnitus; fMRI