目的观察80岁以上高龄老年性聋患者高刺激速率ABR的检查结果并分析其特点,并为老年人后循环缺血及中枢神经系统衰老提供诊断依据。方法选取54例(共108耳)高龄老年性聋患者,全部受试者年龄均大于80岁,平均年龄88.17±4.99岁。每位受试者分别接受高强度下刺激速率为11.1次/s和51.1次/s的短声诱发ABR检查。分析比较在两种不同刺激速率下Ⅰ、Ⅲ、Ⅴ波的峰潜伏期(peak latency,PL),Ⅰ~Ⅲ、Ⅲ~Ⅴ、Ⅰ~Ⅴ波的峰间期(inter-peak la-tency,IPL)。计算高、低刺激速率下峰间期的差值(ΔIPL),并与国内已报道的正常青年人参考值进行对比分析。结果1、高龄老年性聋患者ABR波形分化差,信噪比低;2、刺激速率为51.1次/s时波Ⅰ、Ⅲ、Ⅴ的PL及Ⅰ~Ⅲ、Ⅲ~Ⅴ、Ⅰ~Ⅴ的IPL分别为1.66±0.17、4.06±0.20、6.16±0.20、2.41±0.19、2.10±0.20、4.50±0.19ms,11.1次/s下分别为1.57±0.16、3.87±0.19、5.86±0.19、2.30±0.18、1.99±0.15、4.29±0.16ms,高刺激速率下各参数显著延长。3、两种刺激速率下高龄老年性聋患者Ⅰ~Ⅲ、Ⅲ~Ⅴ、Ⅰ~Ⅴ的ΔIPL分别为0.11±0.18、0.11±0.19、0.22±0.10ms,且男性ΔIPLⅠ~Ⅲ明显高于女性;ΔIPLⅠ~Ⅴ显著高于正常青年参考值(P〈0.001)。4、两种刺激速率下,高龄老年性聋患者波Ⅰ、Ⅲ、Ⅴ的PL比正常青年组均有明显差异(P〈0.05);而51.1次/s刺激速率下高龄老年性聋患者波Ⅰ~Ⅲ、Ⅰ~Ⅴ的IPL,以及11.1次/s时Ⅰ~Ⅲ、Ⅲ~Ⅴ的IPL与正常青年人群参考值均有显著差异(P〈0.05)。结论 80岁以上高龄老年性聋患者的高刺激速率ABR各波形分化较差,与低刺激速率相比,各波峰潜伏期及峰间期明显延长,ΔIPLⅠ~Ⅴ显著高于正常青年参考值。高刺激速率ABR可作为老年人群后循环缺血和中枢神经系统衰老临床诊断的一个重要的指标。
Objective To report characteristics of auditory brainstem responses in presbycusis patients older than 80 years at high stimulus rates, as diagnostic evidence of posterior circulation ischemia and aging of the central nervous system in the elderly. Methods Fifty-four(108 ears) presbycusis patients older than 80 years participated in this study(mean age =88.17±4.99 years). Clicks-evoked ABRs were tested at stimulus rates of 11.1/s and 51.1/s. The peak latency(PL) of waves I,III and V, inter-peak latencies(IPL) of waves I-III, III-V and I-V in response to the low and high rate stimuli were compared. The inter-peak latency differences(ΔIPL) were calculated and compared with normal reference values. Results 1.The ABR waveforms in the presbycusis patients were poorly differentiated, with low signal-to-noise ratios. 2. PLs of waves I, III and V and IPLs of I-III, III-V and I-V were 1.66±0.17, 4.06±0.20, 6.16±0.20, 2.41±0.19, 2.10±0.20 and 4.50±0.19 ms respectively at the stimulus rate of 51.1/s, and 1.57±0.16, 3.87±0.19, 5.86±0.19, 2.30±0.18, 1.99±0.15 and 4.29±0.16 ms, respectively, at the stimulus rate of 11.1/s(p〈0.05). 3. ΔIPLs of I-III, III-V and I-V were 0.11±0.18, 0.11±0.19 and 22±0.10 ms, respectively, and the I-III ΔIPL in males was prolonged compared to females. At the stimulus rate of 51.1/s, I-V ΔIPL was longer than the normal value(P〈0.001). 4. PLs of waves I, III and V in the presbycusis patients, as well as IPLs of I-III,III-V and I-V, at both stimulus rates were distinctly different from those in normal-hearing young subjects(P〈0.05). Conclusion ABR waveforms in presbycusis patients are poorly differentiated. At high stimulus rate, PLs and IPLs are significantly prolonged, and wave I-V ΔIPL is greater than that in normal-hearing young subjects. High stimulus rate ABRs can be an important clinical diagnostic indicator of posterior circulation ischemia and aged central nervous system in the elderly.