Tinnitus intensity dependent gamma oscillations of the contralateral auditory cortex.
BACKGROUND
Non-pulsatile tinnitus is considered a subjective auditory phantom phenomenon present in 10 to 15% of the population. Tinnitus as a phantom phenomenon is related to hyperactivity and reorganization of the auditory cortex. Magnetoencephalography studies demonstrate a correlation between gamma band activity in the contralateral auditory cortex and the presence of tinnitus. The present study aims to investigate the relation between objective gamma-band activity in the contralateral auditory cortex and subjective tinnitus loudness scores.


RESULTS
In unilateral tinnitus patients (N = 15; 10 right, 5 left) source analysis of resting state electroencephalographic gamma band oscillations shows a strong positive correlation with Visual Analogue Scale loudness scores in the contralateral auditory cortex (max r = 0.73, p<0.05).


CONCLUSIONS
Auditory phantom percepts thus show similar sound level dependent activation of the contralateral auditory cortex as observed in normal audition. In view of recent consciousness models and tinnitus network models these results suggest tinnitus loudness is coded by gamma band activity in the contralateral auditory cortex but might not, by itself, be responsible for tinnitus perception.
van der Loo
Elsa
E
Brain Research centre Antwerp for Innovative and Interdisciplinary Neuromodulation (BRAI(2)N), University Hospital Antwerp, Antwerp, Belgium. elsa.vanderloo@ua.ac.be
Gais
Steffen
S
Congedo
Marco
M
Vanneste
Sven
S
Plazier
Mark
M
Menovsky
Tomas
T
Van de Heyning
Paul
P
De Ridder
Dirk
D
D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D001303:Auditory Cortex / Q000033:anatomy & histology* / Q000503:physiopathology*; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006320:Hearing Tests / Q000379:methods; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D008875:Middle Aged; D009991:Oscillometry / Q000379:methods*; D014012:Tinnitus / Q000175:diagnosis* / Q000503:physiopathology*