Functional imaging of unilateral tinnitus using fMRI.
Level 4 - case-series / case-control
Case-control neuroimaging study comparing patients with healthy controls
PubMed 18368576 · doi:10.1080/00016480701793743
What was done
Functional MRI (3T) was conducted to measure neural activity in the inferior colliculus and auditory cortex during presentation of monaural auditory stimuli (dynamically rippled broadband noise at 40 or 70 dB SPL). The study compared 10 individuals with unilateral subjective tinnitus (5 left-sided, 5 right-sided; 5 males) against 12 healthy control subjects (6 males). Participants in both groups had normal hearing or mild hearing loss.
What was found
The sound-evoked response in the inferior colliculus was elevated in tinnitus patients relative to controls without tinnitus. The abstract reports no numerical values, effect sizes, or statistical significance metrics.
Why it matters
The findings provide functional neuroimaging evidence implicating hyperresponsiveness in the inferior colliculus in the pathophysiology of unilateral subjective tinnitus.
Limits
The sample size is very small (10 cases and 12 controls). The abstract provides purely qualitative results without quantitative effect estimates, confidence intervals, or p-values, and omits specific findings regarding the auditory cortex.
Cited by
- supports People with tinnitus who have normal audiometric thresholds exhibit hyperactivity in auditory centers of the brain, specifically in the inferior colliculus.