Study of tonotopic brain changes with functional MRI and FDG-PET in a patient with unilateral objective cochlear tinnitus.
We studied possible brain changes with functional MRI (fMRI) and fluorodeoxyglucose positron emission tomography (FDG-PET) in a patient with a rare, high-intensity "objective tinnitus" (high-level SOAEs) in the left ear of 10 years duration, with no associated hearing loss. This is the first case of objective cochlear tinnitus to be investigated with functional neuroimaging. The objective cochlear tinnitus was measured by Spontaneous Otoacoustic Emissions (SOAE) equipment (frequency 9689 Hz, intensity 57 dB SPL) and is clearly audible to anyone standing near the patient. Functional modifications in primary auditory areas and other brain regions were evaluated using 3T and 7T fMRI and FDG-PET. In the fMRI evaluations, a saturation of the auditory cortex at the tinnitus frequency was observed, but the global cortical tonotopic organization remained intact when compared to the results of fMRI of healthy subjects. The FDG-PET showed no evidence of an increase or decrease of activity in the auditory cortices or in the limbic system as compared to normal subjects. In this patient with high-intensity objective cochlear tinnitus, fMRI and FDG-PET showed no significant brain reorganization in auditory areas and/or in the limbic system, as reported in the literature in patients with chronic subjective tinnitus.
Department of Otorhinolaryngology, Head and Neck Surgery, Lausanne University Hospital, Lausanne, Switzerland.
A-C
AC
Guinchard
Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Naghmeh
N
Ghazaleh
Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Department of Clinical Neurosciences, Lausanne University Hospital, Lausanne, Switzerland.
M
M
Saenz
Department of Radiology, Centre Imagerie Biomédicale, Lausanne University Hospital, Lausanne, Switzerland.
E
E
Fornari
Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Lausanne, Switzerland.
J O
JO
Prior
Department of Radiology, Centre Imagerie Biomédicale, Lausanne University Hospital, Lausanne, Switzerland.
P
P
Maeder
Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Lausanne, Switzerland.
S
S
Adib
Department of Otorhinolaryngology, Head and Neck Surgery, Lausanne University Hospital, Lausanne, Switzerland. Electronic address: raphael.maire@chuv.ch.
R
R
Maire
D000161:Acoustic Stimulation; D000328:Adult; D001298:Audiology; D001303:Auditory Cortex / Q000502:physiology / Q000503:physiopathology; D001921:Brain / Q000503:physiopathology; D003051:Cochlea / Q000503:physiopathology*; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D059906:Neuroimaging; D017084:Otoacoustic Emissions, Spontaneous; D049268:Positron-Emission Tomography; D014012:Tinnitus / Q000503:physiopathology*
D019788:Fluorodeoxyglucose F18
Auditory cortex; Human neuroimaging; Objective tinnitus; Tonotopy