关键词：中耳；创伤性脑损伤；听觉缺陷；电生理学
摘 要：In the second year, we continued our work concerning blast- or concussion-induced traumatic brain injury (TBI) that is often associated with tinnitus. In animal studies, we conducted behavioral testing of tinnitus, anxiety and spatial cognition, MRI-DTI and MEMRI imaging, and electrophysiology in the dorsal cochlear nucleus (DCN), inferior colliculus (IC) and auditory cortex (AC), and histological assays. We found that blast-induced tinnitus was accompanied with high anxiety and hyperactivity in the basolateral nuclei of the amygdala, and hypoactivity in the ipsilateral anterior cingulate cortex, along with variable changes in broadband noise-induced responses in the AC, IC and DCN. Blast also caused significant axonal injuries in auditory white matter tracts and enhanced astroglial activity. In addition, we found that concussion induced acute tinnitus and auditory detection deficits, along with axonal injury in the brainstem. In human studies, we conducted audiological, psychophysical, electroacoustic, and neuroimaging studies. Patients with blastinduced tinnitus showed symmetrical hearing thresholds and abnormal DPOAEs, normal middle ear power reflectance, but with increased fractional anisotropy (FA) of DTI data particularly in the corpus callosum and corona radiata and normal SWI in most patients. Patients with concussions had unpredictable hearing loss with large variability and asymmetric power reflectance values. While patients with blast + concussioninduced had less hearing loss than those with blast or concussion alone, tinnitus loudness was greatest for patients with blast + concussion, least for blast alone, with concussion alone having intermediate loudness.