The association of wavefront aberration and accommodative lag in myopes

Accommodative lags, induced by a target at 33 cm (distance-induced condition) and by a -3.0 D lens (lens-induced condition), and wavefront aberrations were measured in 27 young myopic eyes. The accommodative lags and Strehl ratios derived from the wavefront aberrations in myopes were compared with those from 57 emmetropes. Accommodation was measured using a Canon R-1 autorefractor, while aberrations were measured using a psychophysical ray-tracing technique. In accord with previous results, larger accommodative lags were found for the myopes than the emmetropes in both the lens-induced and distance-induced conditions. The mean Strehl ratio was smaller in the myopes (0.079) than the emmetropes (0.091); this difference approached significance (p = 0.055). In addition, for myopes the accommodative lag was significantly correlated with the Strehl ratio in the lens-induced condition (r = -0.45, p < 0.02) and approached significance in the distance-induced condition (r = -0.35, p = 0.07). No significant correlations were found for emmetropes. Possible reasons to account for these results are discussed.     

国产振幅整合脑功能监护仪的性能研究

采用国产数字化振幅整合脑功能监护仪(CFM 3000)和国外类似产品LECTROMED CFM 5330(LEC-TROMED UK LTD)对20例正常新生儿和8例脑损伤患儿进行同步监测;采用CFM 3000及常规脑电图(EEG)对32例确诊和疑似惊厥患儿同时给予检查。CFM 3000(国产)和LECTROMED CFM 5330(英国)描记的振幅整合脑电图(aEEG)图形类似,20例正常新生儿连续性电活动、睡眠-觉醒周期检出率、宽带和窄带下界、上界电压和时程均值均无统计学差异;8例脑损伤新生儿aEEG图形也无显著性差异。32例惊厥或疑似惊厥新生儿癫痫样波形的检出率与常规EEG比较无统计学差异,Kappa一致性检验Kappa系数为0.552,P为0.001。结果表明:CFM 3000能够反应脑功能变化,性能可靠、稳定。     

角膜塑形镜对近视眼调节微波动幅度和调节滞后的影响

目的 研究近视眼配戴角膜塑形镜后调节微波动幅度和调节滞后的改变.方法 横断面研究.选取在视光门诊规范验配、随诊、配戴角膜塑形镜者15例作为观察组,框架眼镜者15例作为对照组;使用开放视野型红外验光仪(WAM-5500)测量两组在0～4 D的调节刺激下的调节反应,计算相应的调节微波动幅度、调节滞后值和调节误差指数.对两组相关数据进行独立样本t检验.结果 在0、1、2、3、4D调节刺激下,角膜塑形镜组的调节微波动幅度均大于框架眼镜组,且差异有统计学意义(t=3.704、3.277、2.365、2.179、2.591,P均＜0.05).角膜塑形镜组的调节滞后值均小于框架眼镜组,在2,3和4D调节刺激下,两组差异有统计学意义(t=-2.208,-2.244,-2.098,P均＜0.05);而在0和1 D调节刺激下,两组差异无统计学意义(t=-1.974、-1.758,P＞0.05).角膜塑形镜组的调节误差指数小于框架眼镜组,且差异有统计学意义(t=-2.098,P＜0.05).结论 近视眼配戴角膜塑形镜后,调节微波动幅度增大;在高调节需求时,调节滞后值减小,这为其延缓近视的进展提供了一定依据.     

婴幼儿支气管肺炎对心电图P波的影响

目的探讨婴幼儿支气管肺炎心电图P波振幅的特点,为心电图诊断提供科学依据。方法患有支气管肺炎的婴幼儿共143例,分为二组：其中轻症患儿组84例;重症患儿组59例。对照组为同时期门诊查体的正常同龄婴幼儿共96例。对支气管肺炎婴幼儿入院当日、一周PⅡ振幅及一周内心律失常发生率进行比较。结果入院当日PⅡ振幅重症组、轻症组分剐较正常组增高,重症组较轻症组增高（P〈0．01）;入院1周各组间比较,PⅡ振幅重症组较正常组、轻症组增高（P〈0．01）;二组支气管肺炎患儿入院1周内心律失常比较,重症组较轻症组室上性心律失常发生率增高,差异有统计学意义（P〈0．05）。结论婴幼儿支气管肺炎对心电图P波振幅有影响,与病情相关。     

Vibrotactile amplitude discrimination capacity parallels magnitude changes in somatosensory cortex and follows Weber’s Law

In this study, we investigated the changes in perceptual metrics of amplitude discrimination that were observed in ten healthy human subjects with increasing intensities of stimulation. The ability to perceive differences in vibrotactile amplitude changed systematically with increasing stimulus magnitude (i.e., followed Weber’s Law) in a near linear fashion (R ² = 0.9977), and the linear fit determined by the amplitude discrimination task predicted the subjects’ detection thresholds. Additionally, the perceptual metrics correlated well with observations from a previously reported study in which measures of SI cortical activity in non-human primates (squirrel monkeys) evoked by different amplitudes of vibrotactile stimulation were obtained (Simons et al. in BMC Neurosci 6:43, 2005). Stimuli were delivered simultaneously to two different skin sites (D2 and D3), enabling a method for the relatively rapid acquisition of the data. Stability and robustness of the measure, its rapid acquisition, and its apparent relationship with responses previously observed in SI cortex, led to the conclusion that deviations from the baseline values observed in the obtained perceptual metric could provide a useful indicator of cerebral cortical health.     

Resting-state abnormal baseline brain activity in unipolar and bipolar depression

In the present study, we investigated differences in resting-state brain activity in patients with bipolar depression (BD) and unipolar depression (UD) by measuring the amplitude of low-frequency fluctuation (ALFF) of functional magnetic resonance imaging (fMRI) signals. Twenty-one BD and 21 gender-, age-, and education-matched UD patients participated in the fMRI analysis. We compared the differences in the ALFF between the two groups and investigated the correlation between clinical measurements and ALFF in the regions displaying significant group differences. BD subjects displayed significantly decreased ALFF in the left superior parietal lobule and the left posterior insula (l-PI). They also displayed increased ALFF in the right dorsal anterior insula (r-dAI) when compared to the UD group. Moderate negative correlations were found between the Hamilton Depression Rating Scale score (HAMD) and the ALFF in the l-PI for the BD (r=-0.44, P=0.02) and UD (r=-0.45, P=0.02) groups. Our results support the notion that insular subregions may contribute to the precise differentiation between BD and UD.     

无灶性癫痫患者静息态fMRI与注意功能的相关性研究

目的采用静息态功能磁共振成像的低频振幅技术,探讨无灶性癫痫患者低频振幅与注意功能之间可能存在的关系。方法对16例无灶性癫痫患者和16名正常志愿者进行静息态fMRI数据采集及注意功能行为学测试,采用REST软件计算显示无灶性癫痫患者相对于正常人ALFF增高和减弱的区域,对上述的16例无灶性癫痫患者和16例正常对照进行气球叉掉测试,数字符号转换测试及stroop测试检测其注意功能,观察无灶性癫痫患者静息态fMRI与注意功能之间可能存在的联系。结果①无灶性癫痫组和正常对照组相比,ALFF增强的脑区分布在右侧颞叶(15,-90,21)、内侧额叶(0,24,-24)、腹侧前扣带回(-12,30,27)及右侧小脑半球(-51,-57,-4);②无灶性癫痫组和正常对照组相比ALFF减弱的脑区分布在左侧小脑半球及相邻后缘枕叶(-48,-15,39)、后扣带回(60,-21,33)及楔前叶(-6,-54,66);③无灶性癫痫患者的三项注意功能测试反应时间均较正常对照组延长(P<0.01)。Stroop测试结果表明无灶性癫痫组与对照组相比冲突条件下较一致、中性条件下的错误率显著增加。结论无灶性癫痫患者静息状态下表现出异常的脑功能活动方式。长期异常放电对患者的注意功能有明显损害,其中持续注意能力下降,可能与无灶性癫痫患者的颞叶及额叶的病变相关;选择注意能力下降,可能与腹侧前扣带回的损伤密切相关。     

Within-subject consistency of sympathetic-skin-response waveform across different modalities of stimulation

This study was conducted to investigate the intra-subject consistency of the waveform type and the size of the sympathetic skin response (SSR) evoked by different modalities of stimulation. Thirty-eight normal volunteers were enrolled as subjects. SSRs were obtained using three different modalities of stimulations: auditory (a-SSR), electrical (e-SSR), and magnetic (m-SSR). Four stimuli of each modality were applied. The waveforms were classified into two types, P (positive component larger the than negative component) and N (vice versa). P-type waveforms were less frequent in the a-SSR than in the e- and m-SSR. The occurrence of the respective waveforms and the values of maximum amplitudes were significantly correlated among the SSRs evoked by different types of stimulation. Judging from these results, the SSR waveforms and size seemed to be consistent in individuals. The results also suggested that endogenous factors in an individual related to the development of SSRs e.g., individual's emotional state, susceptibility to the surprise effect, and anatomical characteristic were important determinants of the SSR waveforms and maximum amplitude.     

轻度阿尔茨海默病患者静息态脑默认活动网络的fMRI研究

目的 采用静息态功能磁共振(fMRI)技术,探讨轻度阿尔茨海默病(AD)患者的脑默认活动网络(DMN)是否存在异常及其可能的神经机制. 方法 以复旦大学附属华山医院和同济大学附属同济医院神经内科门诊自2009年1月至2010年6月收治的24名轻度AD患者和同期上海社区中整群抽样选择的25名正常老年人为研究对象,对其进行简易智能状态(MMSE)、Mattis痴呆评定量表(DRS)检查和静息态脑功能成像.利用低频振幅(ALFF)算法对全脑静息态数据进行对比分析,观察AD患者相对于正常老年人ALFF有显著差异的区域. 结果 行为学结果显示:轻度AD患者相对对照组成员记忆功能存在明显损害.静息态fMRI结果显示:与对照组比较,AD患者中与记忆密切相关的后扣带回、前额叶中内侧腹侧、前额叶中内侧背侧等脑区ALFF明显减弱. 结论 AD患者静息态脑DMN中与记忆密切相关的脑区节点活动强度减弱,DMN异常在其早期记忆损害的病理机制中起着非常重要的作用.     

基于低频振幅算法的血氧水平依赖功能磁共振成像在无灶性癫痫中的应用

目的 采用基于低频振幅算法的血氧水平依赖功能磁共振成像技术,探讨无灶性癫痫脑活动的神经机制及其意义. 方法 运用功能性磁共振成像技术观察安徽医科大学附属省立医院自2010年9月至2011年3月收治的16例无灶性癫痫患者和同期招募的15名健康对照者脑血氧水平依赖信号的改变;收集其静息态数据,然后运用低频振幅算法对数据进行分析,得到每个受试者的低频振幅统计图,观察无灶性癫痫患者相对于健康对照者低频振荡幅度(ALFF)增高和减弱的区域. 结果 无灶性癫痫组和健康对照组相比ALFF增强的脑区分布在右侧颞叶(MNI坐标分别为15,-90,-21)、内侧额叶(0,24,-24)、腹侧前扣带回(-12,30,27)及右侧小脑半球(-51,-57,-4);而ALFF减弱的脑区分布在左侧小脑半球及相邻后缘枕叶(-48,-15,39)、后扣带回(60,-21,33)及楔前叶(-6,-54,66). 结论 无灶性癫痫患者静息状态下表现出异常的脑功能活动方式,ALFF升高的脑区反映了大脑对癫痫活动的产生、传播等易化作用,表明了癫痫的高活动:而ALFF减低的脑区则反映了大脑对癫痫活动的抑制.