Erwin R J, Shtasel D, Gur R E
Department of Psychiatry, University of Pennsylvania, Philadelphia 19104.
Schizophr Res. 1994 Feb;11(3):251-8. doi: 10.1016/0920-9964(94)90019-1.
The recovery cycle of the P1 component of the auditory evoked potential (50-70 ms latency) has been reported as abnormal in both unmedicated and medicated patients with schizophrenia when a paired stimuli protocol is used to examine recovery. However, findings have been mixed when a stimulus train protocol is used. This study examined the effects of medication history on P1 abnormalities in schizophrenia assessed by a stimulus train protocol. Auditory evoked potentials were recorded from 14 normal controls, 14 neuroleptic naive patients with schizophrenia and 14 previously medicated patients in response to binaural clicks presented at three stimulus rates: 1/s, 5/s and 10/s. Neuroleptic naive patients showed a smaller P1 at the baseline rate (1/s) and greater recovery (less amplitude suppression) at faster rates than did normal controls or previously medicated patients. Additional analyses suggested that this latter effect was not due to smaller baseline P1 amplitudes. Greater recovery in neuroleptic naive patients was not associated with clinical symptomatology contrary to previous findings of the authors for a mixed sample of neuroleptic naive and previously medicated patients. Medication status appears to account for some of the variability in P1 abnormalities in schizophrenia although identification of the underlying mechanism responsible requires further study.
当使用配对刺激方案来检测恢复情况时，据报道，未用药和用药的精神分裂症患者的听觉诱发电位P1成分（潜伏期为50 - 70毫秒）的恢复周期均异常。然而，当使用刺激序列方案时，研究结果则喜忧参半。本研究通过刺激序列方案，考察了用药史对精神分裂症患者P1异常的影响。对14名正常对照者、14名未使用过抗精神病药物的精神分裂症患者以及14名曾使用过药物的患者记录听觉诱发电位，刺激为双耳短声，呈现三种刺激频率：1次/秒、5次/秒和10次/秒。与正常对照者或曾使用过药物的患者相比，未使用过抗精神病药物的患者在基线频率（1次/秒）时P1波幅较小，而在较快频率时恢复程度更大（波幅抑制较小）。进一步分析表明，后一种效应并非由于基线P1波幅较小所致。与作者之前对未使用过抗精神病药物和曾使用过药物的混合样本的研究结果相反，未使用过抗精神病药物的患者恢复程度更高与临床症状无关。用药状态似乎可以解释精神分裂症患者P1异常的部分变异性，尽管确定其潜在机制还需要进一步研究。
