Functional Imaging of Tinnitus / 한양의대학술지

ABSTRACT

Tinnitus is an auditory phantom characterized by the perception of sound without the presence of an external acoustical source. The peripheral auditory system is considered to contribute to the initiation of tinnitus but only explains the severity and distress level to a limited degree. The neuropsychological models of tinnitus have been developed to explain the pathophysiology of tinnitus as a malfunctioning feedforward/feedback signal in the central neural system including the auditory brainstem, limbic system, auditory cortices, and other anatomical features. Functional neuroimaging techniques have been introduced in recent decades and have provided non-invasive tools to assess the working human brain in vivo. Researchers have found these techniques valuable in examining the neural correlates of tinnitus and have been able to not only support the neuropsychological model but to expand it. Though neuroimaging studies on tinnitus only began in 1990s, they have been increasing exponentially in number. In this review, we investigate the current state of functional neuroimaging studies on tinnitus in humans. The characteristics of commonly used functional neuroimaging techniques including positron emission tomography (PET), functional magnetic resonance imaging (fMRI), electroencephalography (EEG) and magnetoencephalography (MEG) are also discussed. We briefly review recent studies on the tinnitus-brain relationship that have used those research tools.