Auditory cortical cvokod rcsponse(ACER) and auditory brainstom cvoked response (ABR) were recorded in guinea pigs before and after irradiation of ^(60)Co γ-ray. A single dose of irradiation on head was 90Gy and 70Gy ...Auditory cortical cvokod rcsponse(ACER) and auditory brainstom cvoked response (ABR) were recorded in guinea pigs before and after irradiation of ^(60)Co γ-ray. A single dose of irradiation on head was 90Gy and 70Gy in two groups, respectively. Two h after irradiation. the threshold shift was 12. 5 dB and 9 dB, and the ACER post-irradiation amplitude ex- ceeded the maximum pre-irradiation value by 20% and 37%. Six h after irradiation, the threshold shift increased to 37 dB and the maximum amplitnde decreased to the level of pre-irradiation in 70Gy-group. In another group, right auditory bulla arca was irradiated with a total dose of 45Gy in a course of six fractions/two weeks. Fourteen d after irradiation, the threshold shift of ABR was 118 dB and the latency of wave I was longer. The amplitude-intensity curve was after irradiation. Histological observation using scanning showed that only outer hair- cells in the basal coil of the cochlea were 6 h after irrdiation 50Gy-group. Bul 16 h later, outer, hair cells in all coils of the cochlea were found to be destroyed extensively and inner cells were destroyed slightly. In 45Gy-group, 14 d after irradiation, outer hair cells in all coils of the cochlea were damaged and no inmer hair cell was injured severely.展开更多
文摘Auditory cortical cvokod rcsponse(ACER) and auditory brainstom cvoked response (ABR) were recorded in guinea pigs before and after irradiation of ^(60)Co γ-ray. A single dose of irradiation on head was 90Gy and 70Gy in two groups, respectively. Two h after irradiation. the threshold shift was 12. 5 dB and 9 dB, and the ACER post-irradiation amplitude ex- ceeded the maximum pre-irradiation value by 20% and 37%. Six h after irradiation, the threshold shift increased to 37 dB and the maximum amplitnde decreased to the level of pre-irradiation in 70Gy-group. In another group, right auditory bulla arca was irradiated with a total dose of 45Gy in a course of six fractions/two weeks. Fourteen d after irradiation, the threshold shift of ABR was 118 dB and the latency of wave I was longer. The amplitude-intensity curve was after irradiation. Histological observation using scanning showed that only outer hair- cells in the basal coil of the cochlea were 6 h after irrdiation 50Gy-group. Bul 16 h later, outer, hair cells in all coils of the cochlea were found to be destroyed extensively and inner cells were destroyed slightly. In 45Gy-group, 14 d after irradiation, outer hair cells in all coils of the cochlea were damaged and no inmer hair cell was injured severely.
