精神分裂症幻听患者初级听觉皮质的脑磁图研究

Magnetoencephalography study of primary auditory cortex in male schizophrenia patients with auditory hallucination

目的探讨在不同频率纯音刺激下男性精神分裂症幻听患者初级听觉皮质的脑磁图（MEG）定位。方法对均为右利手的10例男性精神分裂症幻听患者（研究组）和11名男性健康受试者（对照组），分别给予频率为0．5，2，4，8kHz的纯音刺激，强度90dB，持续200ms，刺激声间隔1s。用脑磁图设备记录刺激后产生的听觉诱发磁场，并将MEG资料叠加到核磁共振成像以获得磁源性影像。结果（1）对照组初级听觉皮质均定位于双侧颞横回；与对照组比较，研究组右侧初级听觉皮质位置更靠近颞横回外部，左侧明显偏向颞上回后外下部（P〈0．05）。（2）在分别给予2kHz和4kHz纯音刺激时，研究组大脑双侧M100潜伏期[2kHz：左（97±t6）ms，右（97±10）ms，4kHz：左（93±13）ms，右（99±14）ms]均短于对照组[2kHz：左（121±15）ms，右（113±6）ms，4kHz：左（113±13）ms，右（114±6）ms]（均P〈0．01），而波幅[2kHz：左（89±10）fT，右（118±37）fT，4kHz：左（81±9）fT，右（108±14）fT]高于对照组[2kHz：左（73±12）fT，右（79±13）fT，4kHz：左（69±14）fT，右（81±20）fT]（均P〈0．05—0．01）。结论男性精神分裂症幻听患者的初级听觉皮质位置与正常人不同，其M100波幅高，潜伏期短，这些功能及解剖结构的异常可能是精神分裂症幻听产生的病理生理机制之一。

Objective To investigate the localization of primary auditory cortex by using magnetoencephalography in male schizophrenia patients with auditory hallucination by various frequency of pure tone stimuli and to explore the pathophysiologic mechanism of auditory hallucination. Methods Ten male schizophrenia patients with auditory hallucination and 11 matched healthy subjects were recruited in the study. All the participants were right handed, and given various frequencies of 0. 5, 2, 4, 8 kHz pure tone stimuli, with intensity of 90 dB sound pressure level, persistent time of 200 ms, interstimulus interval of 1 second. The auditory evoked magnetic fields （AEF） were recorded by MEG after stimulus, and the MEG data were superimposed on MRI to obtain MSI. Results AEF M100 was induced in all subjects after giving the binaural stimuli, and the primary auditory cortex was localized in the bilateral transverse temporal gyri in controls, while in the outer of the transverse temporal gyri in the right hemispheric, and in the posterior- exterior-low part of superior temporal gyrus in the left hemispheric in patients. M100 latencies in bilateral globe were shorter in patients [ （left 97 ±16） ms, （ right 97 ± 10） ms] than controls [ （ left 121 ± 15） ms, （right 113±6）ms] and the amplitudes were higher in patients [ （left 89 ± 10）fT, （right 118 ±37）fT] than controls [ （left 73 ± 12 ）fT, （right 79 ± 13 ）fT ] （ P 〈 0. 05 -0. 01 ）. Conclusions The localization of primary auditory cortex in male schizophrenia patients with auditory hallucination is different from healthy people, with shortened M100 latency and increased amplitudes in patients. These function and anatomical structure abnormality could be one of the pathophysiologic mechanism of auditory hallucination in schizophrenia.