Neural mechanism of residual inhibition of tinnitus in cochlear implant users.
Residual inhibition is a transient suppression of tinnitus after auditory stimulation has stopped. We used positron emission tomography to study brain regions underlying residual inhibition in three tinnitus patients with cochlear implants and six normal hearing controls. Regional cerebral blood flow was measured and compared under two conditions: with tinnitus and during the residual inhibition of tinnitus. The right anterior middle and superior temporal gyri (Brodmann areas 21 and 38) were activated during residual inhibition, while the right cerebellum was activated during tinnitus perception in the tinnitus patients. No significant activation was observed in the normal controls. Our results suggest that tinnitus and residual inhibition are related to cortical networks of auditory higher-order processing, memory and attention.
Osaki
Yasuhiro
Y
Department of Otorhinolaryngology and Sensory Organ Surgery, Osaka University Graduate School of Medicine, Japan. osaki@tracer.med.osaka-u.ac.jp
Nishimura
Hiroshi
H
Takasawa
Masashi
M
Imaizumi
Masao
M
Kawashima
Takayuki
T
Iwaki
Takako
T
Oku
Naohiko
N
Hashikawa
Kazuo
K
Doi
Katsumi
K
Nishimura
Tsunehiko
T
Hatazawa
Jun
J
Kubo
Takeshi
T
D000368:Aged; D002531:Cerebellum / Q000098:blood supply / Q000000981:diagnostic imaging / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology; D003054:Cochlear Implants; D003638:Deafness / Q000503:physiopathology; D006801:Humans; D008297:Male; D049268:Positron-Emission Tomography; D013702:Temporal Lobe / Q000098:blood supply / Q000000981:diagnostic imaging / Q000502:physiology; D014012:Tinnitus / Q000000981:diagnostic imaging / Q000503:physiopathology*