[Study on the bilaterally recorded ABR in the experimental model of acoustic tumor]

The ABRs were bilaterally recorded with monaural stimulation from the animal model of acoustic tumor in 10 rats. It was found that the waveform of ABRs recorded from the right dura was different from the left one. A major feature of right ABRs was that the amplitudes of wave II and wave III were decreased by 3.53 +/- 1.21 microV and 3.94 +/- 1.16 microV respectively, and that the latencies of wave IV and wave V were increased by 0.88 +/- 0.11ms and 1.37 +/- 0.10ms respectively. It suggested that the cochlear nerve near the cochlear nucleus was pressured. A major feature of left ABRs was that the amplitudes of wave III were prominently reduced by 7.02 +/- 0.73 microV and wave IV and V were mixed together. The results implied that the waves generated after wave III might be affected by the bilateral auditory pathway.