Poster A2, Saturday, March 25, 5:00 – 7:00 pm, Pacific Concourse
Prefrontal and parietal recruitment during the MSIT selective attention task predicts rTMS treatment outcome in patients with subjective tinnitus
George James1, Jeff Thostenson1, Ginger Brown1, Gwendolyn Carter1, Mark Mennemeier1; 1University of Arkansas for Medical Sciences
Subjective idiopathic tinnitus is a disorder with no discernible etiology characterized by intrusive phantom perception of sound. Recent clinical trials suggest that repetitive transcranial magnetic stimulation (rTMS) can reduce tinnitus awareness. Based upon patients’ anecdotal reports that rTMS reduced awareness of phantom sounds but not their intensity, we hypothesized that subjective idiopathic tinnitus may be a disorder of selective attention. To test this hypothesis, a subset of patients enrolled in a clinical trial using rTMS to treat tinnitus underwent functional magnetic resonance imaging (fMRI) while performing the Multi-Source Interference Task (MSIT) selective attention task. Twelve participants (mean(sd) age = 49(15); 3 female and 9 male) underwent fMRI at Baseline (prior to rTMS) and again after three rTMS treatment arms (one week of Sham, 1Hz, and 10Hz rTMS; with 3 week washout between treatments). Using a 200 region of interest (ROI) brain atlas, general linear modeling (GLM) estimated participants’ change in brain activity for the MSIT contrast of Incongruent vs. Congruent stimuli at Baseline. Linear regression with bootstrap resampling then used these ROIs’ Baseline GLM beta values to predict percent change in tinnitus awareness following rTMS treatment. After FDR correction for multiple comparisons, Baseline MSIT activity for 26 ROIs significantly predicted rTMS response. Greater recruitment of these regions at Baseline - which predominantly consisted of bilateral prefrontal and parietal cortices - corresponded to poorer treatment outcome. These findings support the use of functional neuroimaging to guide patient selection for rTMS treatment of tinnitus.
Topic Area: ATTENTION: Auditory