Functional imaging of unilateral tinnitus using fMRI

Abstract

Conclusions: This article shows that the inferior colliculus plays a key role in unilateral subjective tinnitus.

Objectives: The major aim of this study was to determine tinnitus-related neural activity in the central auditory system of unilateral tinnitus subjects and compare this to control subjects without tinnitus.

Subjects and methods: Functional MRI (fMRI) was performed in 10 patients (5 males) with unilateral tinnitus (5 left-sided, 5 right-sided) and 12 healthy subjects (6 males); both groups had normal hearing or mild hearing loss. fMRI experiments were performed using a 3T Philips Intera Scanner. Auditory stimuli were presented left or right and consisted of dynamically rippled broadband noise with a sound pressure level of 40 or 70 dB SPL. The responses of the inferior colliculus and the auditory cortex to the stimuli were measured.

Results: The response to sound in the inferior colliculus was elevated in tinnitus patients compared with controls without tinnitus.