精神分裂症幻听患者初级听觉皮质的脑磁图研究

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0.5,2,4,8 kHz的纯音刺激,强度90 dB,持续200ms,刺激声间隔1 s.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2 kHz和4kHz纯音刺激时,研究组大脑双侧M100潜伏期[2 kHz:左(97±16)ms,右(97±10)ms,4 kHz:左(93±13)ms,右(99±14)ms]均短于对照组[2 kHz:左(121±15)ms,右(113±6)ms,4 kHz:左(113±13)ms,右(114±6)ms](均P<0.01),而波幅[2 kHz:左(89±10)fT,右(118±37)fT,4 kHz:左(81±9)fT,右(108±14)fT]高于对照组[2 kHz:左(73±12)fT,右(79±13)fT,4 kHz: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.     

母语为汉语正常人听觉性语言中枢的定位

目的采用脑磁图(magnetoencephaiography MEG)的等价偶极子定位法(equivalent current dipole,ECD)和合成孔径磁场定位法(SAM Synthetic Aperture Magnetometry SAM)定位母语为汉语健康自愿者的听觉性语言中枢探讨汉字的语言加工过程。方法采用北京医科大学附属第一医院制定的利手评定标准,对15例母语为汉语的健康受试者进行利手评定。给予听动物名称、植物名称的语言任务刺激,采用MEG记录刺激后产生的诱发磁场。将采集的数据与MRI叠加获得听觉性语言中枢定位。结果所有受试者听动物名称、植物名称均在双侧大脑半球诱发出明显的晚发磁反应波,其中左侧大脑半球磁反应波分化较右侧大脑半球好。听觉性语言中枢定位于左侧颞中回、颞上回、缘上回。结论母语为汉语的正常人听觉性语言中枢与经典的语言中枢基本相符,即听觉性语言中枢定位于左侧颞中回、颞上回,缘上回。     

磁源成像在母语为汉语正常人的语言功能定位中的应用

目的 采用脑磁图（magnetoencephalograph，MEG）的等价电流偶极子定位法（Equivalent current dipole，ECD）和合成孔径磁场定位法（SAMSynthetic、Aperture Magnetometry，SAM）定位母语为汉语的健康自愿者的语占中枢，探讨汉字的语言处理过程。方法 对10例母语为汉语的健康受试者给予默读真词、假词的语言任务刺激，记录刺激后产生的诱发磁场，将采集的数据与MRI叠加获得磁源性影像（MSI Magnetic source imaging）语占功能区定位川同样的方法对4例胶质瘤患者进行术前语言功能区定位，术中皮层电刺激所定位语言功能区，明确是否产生言语障碍。结果 所有受试者真词、假词均在双侧大脑半球诱发出明显的晚期磁反应波，左侧大脑半球磁反应波分化较右侧大脑半球好，Broea区俯于额下回后部，Wernicke区位于颞中同、颢上回、缘上回，Wernieke区先于Broca区出现。胶质瘤患者术巾电刺激所定位的Broca区、Wernicke区均产生言语障碍：结论母语为汉语的正常人的Broca区Wernieke区与经典的语言中枢糕本相符，MEG定位语言中枢的技术是可行的。     

抑郁症患者情绪图片刺激早期低频脑磁图研究

目的：探讨抑郁症患者给予视觉情绪图片刺激早期0～100ms、100～200ms、200～300ms3个时段8～30Hz的神经磁场激活特征。方法：8例抑郁症患者及12例健康右利手对照者,在给予国际情绪图片库（IAPS）正性、中性、负性情绪图片刺激同时记录脑磁图信号,使用SPM8b软件进行数据分析：设两样本t检验P〈0.01（未校正）和K值≥10个体素范围为差异有统计学意义。结果：与对照组相比,抑郁组在正性情绪图片刺激下,100～200ms内的左侧额下回,右侧的终板旁回、额内侧回、海马回激活增强。在中性情绪图片刺激下,抑郁组在0～100ms的右侧豆状核、岛叶、额上回,左内侧额叶,100～200ms内的右侧岛叶、豆状核壳核及屏状核,左侧额下回、额上回、颞上回,200～300ms内的右侧岛叶、豆状核、尾状核体激活增强。负性情绪图片刺激下抑郁组在0～100ms内的右侧颞上回、岛叶、尾状核头部、额中下回激活增强,100～200ms内的右侧额中回、尾状核体,200～300ms内右额下回激活增强。此外还比较一致的发现抑郁组在楔前叶、后扣带回等顶叶脑区激活降低。结论：抑郁个体起注意调节功能的顶叶脑区如楔前叶功能不足,对视觉皮质向前部脑区情绪信息颞叶底部传递通路抑制不足,腹侧前额皮质、岛叶过度的激活,可能是抑郁症的一个发病基础。     

男性精神分裂症患者脑侧化与幻听的功能磁共振成像研究

目的利用事件相关功能磁共振成像（fMRI）在体研究精神分裂症伴有幻听的男性患者左右侧化声音激活脑区的差异，以验证幻听是由脑侧化异常产生的假说。方法男性健康志愿者13名（正常对照组），幻听和非幻听偏执型精神分裂症男性患者各13例，接受预先编制的左右侧化声音刺激，进行功能磁共振扫描。结果（1）组内比较：与右侧化声音刺激相比，正常对照组在辨别左侧化声音刺激时显著激活了左楔前叶和右旁中央小叶（FDR校正，P〈0．01，体素值〉10）；两个患者组组内左右侧化声音显著激活脑区比较，差异均无统计学意义。（2）组间比较：与幻听组相比，正常对照组在辨别左侧化声音刺激时右旁中央小叶显著激活；与非幻听组相比，正常对照组在辨别左侧化声音刺激时显著激活两侧颞上回、左楔前叶、两侧扣带回和左缘上回，而在辨别右侧化声音刺激时两侧颞上回、右颞中回和左脑岛显著激活；与非幻听组相比，幻听组无论在辨别左或右侧化声音刺激时均引起左侧颞横回激活（P〈0．001，未校正，体素值〉50）。结论精神分裂症患者正常的语言侧化减弱，而幻听的产生可能与左脑尤其是左颞横回的功能障碍有关。     

首发精神分裂症患者倒背数字作业的fMEI研究

目的利用功能磁共振成像(fMRI)探讨首发精神分裂症患者倒背数字作业激发图像的特点.方法 36例符合ICD-10诊断标准的(首发)精神分裂症患者及18名健康志愿者进行以倒背数字作业(backward digit span task, BDST)作为刺激模式、采用组块(block)设计的fMRI检查,经工作站处理后获功能图像.用阳性和阴性症状量表(PANSS)评价精神分裂症患者精神症状的严重程度. 结果 (1)健康志愿者与精神分裂症患者激活脑区的范围均较广泛,健康志愿者的左侧额上回、双侧额中回、左侧额下回、左侧中央前回、左侧顶上小叶、左侧缘上回、左侧颞下回及左侧枕颞外侧回等脑区均有明显激活.两组激活的脑区在额叶、颞叶、顶叶、枕叶及扣带回的分布,以及各脑区内部分布的差异均没有显著性(P>0.05).(2)健康志愿者与精神分裂症患者激活计数左侧额上回分别为16和11,左侧额下回分别为15和12,左侧中央前回分别为16和17,左侧颞下回分别为14和12,左侧顶上小叶分别为14和14,左侧缘上回分别为14和7,左侧枕颞外侧回分别为14和7,右侧中央前回分别为13和7,右侧枕颞外侧回分别为11和8,两组上述部位激活计数的差异均有显著性(P均＜0.05).(3)健康志愿者与精神分裂症患者左侧额叶背外侧的激活平均体积分别为(362±296)个体素和(79±101)个体素,差异有非常显著性(P=0.001);右侧顶叶后下部的激活平均体积分别为(448±273)个体素和(193±236)个体素,差异有显著性(P=0.039). 结论早期精神分裂症患者可能存在工作记忆缺陷,包括激活信息的保持及执行控制过程,激活信息的保持缺陷可能与左侧额叶腹外侧及顶叶后下部的功能低下有关,而执行控制缺陷可能与左侧额叶背外侧的功能低下有关.     

早期特发性全面性癫痫大脑皮质厚度脑图谱的建立研究

目的 采用大脑磁共振T1图像及先进的图像分析软件,构建初次就诊的特发性全面性癫痫(Idiopathic generalized epilepsy,IGE)大脑皮质厚度脑图谱。方法 选取2020年1月1日—2021年12月31日于寿光市人民医院就诊的27例初诊为IGE患者和29名正常对照组获得高分辨率三维T1图像。利用Freesurfer软件的定位识别计算系统,计算每个脑区皮质厚度的具体数值,利用图像分析软件,将皮质厚度数值制作成脑图谱。利用两样本t检验,形成差异脑图谱,分析IGE患者同正常人皮质厚度的差异。运用配对t检验进行对两组数据进行组内比较,探讨皮质厚度偏侧性的改变。结果 IGE脑图谱中皮质厚度较厚的脑区为右左侧颞极、右左侧内嗅皮层、右侧前扣带回头部、右左侧岛叶、右左侧颞中回、右侧颞下回、左侧前扣带回头部、左侧前扣带回尾部、左侧颞下回、左右侧梭状回、左侧额极;皮质厚度较薄的区域为右左侧距状旁回、右左侧楔叶、左右侧舌回、左右侧中央后回、左侧枕外侧回、右左侧顶上回;与正常人脑皮质厚度脑图谱比较,皮质厚度分布规律大致相仿;与正常人比较,IGE大脑皮质厚度发生改变的区域为双侧额上回、双侧...     

首发未用药精神分裂症与精神分裂症患者健康子女静息态脑功能低频振幅研究

目的探讨首发未用药精神分裂症患者和精神分裂症患者健康子女脑功能磁共振低频振幅(amplitude of low frequency fluctuation,ALFF)的共性与差异。方法应用静息态功能磁共振ALFF的方法对年龄30岁的23例首发未用药精神分裂症患者、25名精神分裂症患者健康子女以及29名健康对照进行大脑范围内ALFF值比较。结果与对照组相比,患者组和患者子女组在左侧颞下回后部、左侧海马旁回、左侧海马、右侧中央后回、双侧楔前叶的ALFF值有统计学差异(P0.05),而患者组和患者子女组间在以上脑区的ALFF值无统计学差异(P0.05);与患者子女组和对照组相比,患者组在左侧颞下回前部、左侧颞上极、双侧距状裂周围皮层的ALFF值有统计学差异(P0.05),患者子女组和对照组间在以上脑区的ALFF值无统计学差异(P0.05)。结论首发未用药精神分裂症患者以及精神分裂症患者健康子女都存在脑功能异常;左侧颞下回后部、左侧海马旁回、左侧海马、右侧中央后回、双侧楔前叶可能是与精神分裂症遗传素质性相关的脑区;左侧颞下回前部、左侧颞上极、双侧距状裂周围皮层可能是与疾病状态性相关的脑区。     

额颞癫痫术前评估脑磁图与神经导航应用研究

目的研究脑磁图(MEG)与神经导航在额颞癫痫术前评估中的应用。方法选取手术治疗32例额颞癫痫患者临床资料分析。患者术前行致痫灶定位和智商、记忆和语言评估;MEG确定语言、记忆优势半球,明确语言功能区范围和记忆功能情况。术中应用美国Medtronic Stealhealth S7手术导航系统引导手术切除病变和致痫灶,保护神经功能。术后1年复测智商、记忆和语言检查,统计分析手术前后数据。癫痫术后随访13～41个月,平均(24.7±3.61)个月,依照Engel's分级标准,判定癫痫术后疗效。结果 32例额颞癫痫患者MEG检查顺利。MEG能够精确定位语言功能区位置。其中22例语言优势半球为左侧,10例在右侧。术后1年复测智商、记忆和语言,统计显示言语智商与总智商提高(P0.05),记忆商、操作智商无明显变化(P0.05)。患者术后恢复良好,无语言、记忆及肢体功能损伤。癫痫疗效:Engel'sI级15例,Engel'sⅡ级14例;Engel'sⅢ级3例。结论 MEG联合神经导航对于额颞癫痫患者术前语言和记忆优势半球的定侧、定位和制定手术计划,保护皮质功能、避免严重术后并发症,提高癫痫手术疗效具有重要价值。     

~(18)F-FDG PET显像观察特发性快眼动睡眠期行为障碍患者脑葡萄糖代谢特点的研究

目的探讨~(18)F-FDG PET显像观察特发性快眼动睡眠期行为障碍(iRBD)患者脑葡萄糖代谢改变和iRBD脑葡萄糖代谢改变与病程间的相关性。方法纳入多导睡眠监测(PSG)确诊的iRBD患者20例(iRBD组)和年龄、性别匹配的健康对照者19例(对照组)。两组均行~(18)F-FDG PET脑显像。基于自动解剖标记模板将大脑划分为90个左右对称的脑区,计算各脑区葡萄糖代谢半定量值。对iRBD组和对照组各脑区葡萄糖代谢半定量值进行独立样本t检验;并对iRBD组脑葡萄糖代谢改变与病程行Pearson相关分析。结果 (1)与对照组比较,iRBD组的双侧背外侧额上回、双侧眶部额上回、双侧眶部额中回、双侧海马、双侧海马旁回、双侧杏仁核、左侧眶部额下回、左侧岛叶、左侧内侧与旁扣带脑回、左侧中央旁小叶、左侧苍白球的葡萄糖代谢半定量值均增高(P0.05);双侧距状裂周围皮质、双侧楔叶、双侧舌回、双侧枕上回、双侧枕中回、双侧枕下回、双侧角回、双侧颞上回、双侧颞中回、右侧颞横回的葡萄糖代谢半定量值均降低(P0.05)。Pearson相关分析结果,iRBD组双侧杏仁核、双侧颞上回、右侧楔叶、右侧枕上回、右侧颞横回、左侧海马、左侧颞中回的葡萄糖代谢半定量值与病程呈正相关(P0.05);而双侧眶部额上回、双侧眶部额中回、左侧中央旁小叶、左侧眶部额下回、左侧内侧和旁扣带回、右侧背外侧额上回、右侧海马旁回的葡萄糖代谢半定量值与病程呈负相关(P0.05)。结论 iRBD患者脑内存在疾病相关的葡萄糖代谢水平改变,有助于客观评估iRBD病情的变化。     

Transplantation of conditionally immortal auditory neuroblasts to the auditory nerve

Cell transplantation is a realistic potential therapy for replacement of auditory sensory neurons and could benefit patients with cochlear implants or acoustic neuropathies. The procedure involves many experimental variables, including the nature and conditioning of donor cells, surgical technique and degree of degeneration in the host tissue. It is essential to control these variables in order to develop cell transplantation techniques effectively. We have characterized a conditionally immortal, mouse cell line suitable for transplantation to the auditory nerve. Structural and physiological markers defined the cells as early auditory neuroblasts that lacked neuronal, voltage-gated sodium or calcium currents and had an undifferentiated morphology. When transplanted into the auditory nerves of rats in vivo, the cells migrated peripherally and centrally and aggregated to form coherent, ectopic 'ganglia'. After 7 days they expressed beta 3-tubulin and adopted a similar morphology to native spiral ganglion neurons. They also developed bipolar projections aligned with the host nerves. There was no evidence for uncontrolled proliferation in vivo and cells survived for at least 63 days. If cells were transplanted with the appropriate surgical technique then the auditory brainstem responses were preserved. We have shown that immortal cell lines can potentially be used in the mammalian ear, that it is possible to differentiate significant numbers of cells within the auditory nerve tract and that surgery and cell injection can be achieved with no damage to the cochlea and with minimal degradation of the auditory brainstem response.     

Modified activity of the human auditory cortex during auditory hallucinations.

Previous reports have shown abnormalities in brain metabolism and evoked responses of schizophrenic patients with hallucinations. The authors recorded electric and magnetic auditory responses during transitory auditory hallucinations in two patients. Small but replicable response delays occurred during hallucinations. The results suggest that the effect of hallucinations on auditory cortex activity is similar to the effect of real sounds.     

A case of auditory agnosia with the lesion of bilateral auditory radiation

A 53-year-old man showed central auditory disturbance with recurrent cerebral hemorrhage. At his acute stage he had deafness and auditory anosognosia. Two or three months later, there was no deafness and auditory anosognosia, but he could not comprehend words, environmental sounds and music. Auditory brainstem responses showed no peripheral or brainstem damage, and the lesion of bilateral auditory radiation was detected by MRI. His auditory agnosia did not improve over one and a half year. There is no report like such permanent auditory agnosia with the lesion of bilateral subcortical temporal lobe.     

Connections of functional areas in the mustached bat's auditory cortex with the auditory thalamus

The auditory thalamus is the major target of the inferior colliculus and connects in turn with the auditory cortex. In the mustached bat, biosonar information is represented according to frequency in the central nucleus of the inferior colliculus (ICc) but according to response type in the cortex. In addition, the cortex has multiple areas with neurons of similar response type compared to the single tonotopic representation in the ICc. To investigate whether these transformations occur at the level of the thalamus, we injected anatomical tracers into physiologically defined locations in the mustached bat's auditory cortex. Injections in areas used for target ranging labeled contiguous regions of the auditory thalamus rather than separate patches corresponding to regions that respond to the different harmonic frequencies used for ranging. Injections in the two largest ranging areas produced labeling in separate locations. These results indicate that the thalamus is organized according to response type rather than frequency and that multiple mappings of response types exist. Injections in areas used for target detection labeled thalamic regions that were largely separate from those that interconnect with ranging areas. However, injections in an area used for determining target velocity overlapped with the areas connected to ranging areas and areas involved in target detection. Thus, separation by functional type and multiplication of areas with similar response type occurs by the thalamic level, but connections with the cortex segregate the functional types more completely than occurs in the thalamus.     

Characterizing the auditory changes in tumor metastasis to the bilateral internal auditory canals.

We report the changes in auditory function in a patient with tumor metastasis to the bilateral internal auditory canals (IAC). The hearing gradually deteriorated at frequencies below 1 kHz and above 4 kHz, with the auditory brainstem response (ABR) eventually becoming absent in both ears. However, distortion product otoacoustic emissions (DPOAE) were present at low frequencies, which suggests that the organ of Corti in its upper turn remained unaffected by tumor invasion. Metastatic tumors in the bilateral IAC have been reported to mimic neurofibromatosis type 2, and radiological differentiation from acoustic schwannoma is difficult. We characterize the hearing deterioration caused by metastasis of malignant tumors in the IAC.     

Central auditory processing in patients with auditory hallucinations

OBJECTIVE: Data from a full assessment of auditory perception in patients with schizophrenia were used to investigate whether auditory hallucinations are associated with abnormality of central auditory processing. METHOD: Three groups of subjects participated in auditory assessments: 22 patients with psychosis and a recent history of auditory hallucinations, 16 patients with psychosis but no history of auditory hallucinations, and 22 normal subjects. Nine auditory assessments, including auditory brainstem response, monotic and dichotic speech perception tests, and nonspeech perceptual tests, were performed. Statistical analyses for group differences were performed using analysis of variance and Kruskal-Wallis tests. The results of individual patients with test scores in the severely abnormal range (more than three standard deviations from the mean for the normal subjects) were examined for patterns that suggested sites of dysfunction in the central auditory system. RESULTS: The results showed significant individual variability among the subjects in both patient groups. There were no group differences on tests that are sensitive to low brainstem function. Both patient groups performed poorly in tests that are sensitive to cortical or high brainstem function, and hallucinating patients differed from nonhallucinating patients in scores on tests of filtered speech perception and response bias patterns on dichotic speech tests. Six patients in the hallucinating group had scores in the severely abnormal range on more than one test. CONCLUSIONS: Hallucinations may be associated with auditory dysfunction in the right hemisphere or in the interhemispheric pathways. However, comparison of results for the patient groups suggests that the deficits seen in hallucinating patients may represent a greater degree of the same types of deficits seen in nonhallucinating patients.     

Comparing the effects of auditory deprivation and sign language within the auditory and visual cortex

To investigate neural plasticity resulting from early auditory deprivation and use of American Sign Language, we measured responses to visual stimuli in deaf signers, hearing signers, and hearing nonsigners using functional magnetic resonance imaging. We examined "compensatory hypertrophy" (changes in the responsivity/size of visual cortical areas) and "cross-modal plasticity" (changes in auditory cortex responses to visual stimuli). We measured the volume of early visual areas (V1, V2, V3, V4, and MT+). We also measured the amplitude of responses within these areas, and within the auditory cortex, to a peripheral visual motion stimulus that was attended or ignored. We found no major differences between deaf and hearing subjects in the size or responsivity of early visual areas. In contrast, within the auditory cortex, motion stimuli evoked significant responses in deaf subjects, but not in hearing subjects, in a region of the right auditory cortex corresponding to Brodmann's areas 41, 42, and 22. This hemispheric selectivity may be due to a predisposition for the right auditory cortex to process motion; earlier studies report a right hemisphere bias for auditory motion in hearing subjects. Visual responses within the auditory cortex of deaf subjects were stronger for attended than ignored stimuli, suggesting top-down processes. Hearing signers did not show visual responses in the auditory cortex, indicating that cross-modal plasticity can be attributed to auditory deprivation rather than sign language experience. The largest effects of auditory deprivation occurred within the auditory cortex rather than the visual cortex, suggesting that the absence of normal input is necessary for large-scale cortical reorganization to occur.     

Tonotopic organization of the human auditory cortex revealed by transient auditory evoked magnetic fields

The tonotopic organization of the human auditory cortex has been investigated by systematic measurements of magnetic fields evoked by tone-bursts with carrier frequencies of 250, 500, 1000, 2000 and 4000 Hz. The measured field distribution changes with both time elapsed since stimulus onset and frequency of the stimulus. Nevertheless, the field distribution has always the same overall features and can be approximated by that of an equivalent current dipole located in a semi-infinite volume. This model can be described in terms of 5 parameter values: 3 orthogonal coordinates specifying the dipole location, and amplitude and angle of the dipole moment. The amplitude of the dipole moment is maximal at about 100 msec ('component 100m') and 160 msec ('component 160m') after stimulus onset. The depth estimated for the generator site of the 100m component shows a logarithmic dependence on test frequency whereas no similar behaviour could be observed for the 160m component. Anatomical studies performed in cadaver heads suggest that the equivalent current dipoles of both the 100m and the 160m component are located in the transverse temporal gyri.