高热惊厥患儿视听诱发电位的研究

【目的】获得一组高热惊厥（febrile convulsion，FC）患儿的视听同步诱发电位的试验室参考值，与同时检测的听性脑干反应（auditory brainstem response，ABR）和闪光视觉诱发电位（flash visual evoked potentials，FVEP）进行对比，讨论视听同步诱发电位的特点，为临床早期同步发现并诊断婴幼儿视听功能障碍提供有力的电生理技术支持。【方法】30例1～3岁FC患儿，于惊厥24h内和惊厥一周后分别进行单独ABR、FVEP和视听同步诱发电位的检测。【结果】①2～3岁组FC患儿单独ABR各波的潜伏期、波问期及单独FVEP各波潜伏期均长=F其它年龄组；②同步ABR—FVEP各波在同步诱发后波形分化良好，潜伏期稳定，较单独ABR和单独FVEP检测波变得更易辨认；③2～3岁组FC患儿同步FVEP—ABR各波的潜伏期、波问期均长于其它组；④FVEP在同步诱发电位中占主导地位，对同步ABR潜伏期影响显著；⑤FC患儿同步ABR和同步FVEP的标准差较单独ABR和FVEP减小，同步ABR和FVEP的异常率较单独ABR和FVEP的异常率有明显提高。【结论】同步诱发电位可早期发现并诊断FC患儿视听功能障碍。     

RT-3DE定量评价心梗患者PCI术前后左室功能的变化

为探讨实时三维超声心动图(RT-3DE)定量评估心梗患者经皮冠状动脉介入治疗(PCI)术前后左室收缩功能及同步性参数的变化,选取100例接受PCI治疗的心肌梗死患者和100例正常对照组,应用RT-3DE技术对正常对照组和心梗患者PCI术前及术后1个月测量左心室收缩功能及同步性参数并进行比较。心梗患者PCI术前组左心室各功能参数值均劣于正常对照组,而术后1个月左心室各参数值均较术前明显改善。PCI术前、术后应用RT-3DE能够准确定位、定量反映左心室收缩功能及运动同步性,对心肌梗死的临床诊断及疗效评估具有重要价值。     

Time-of-day effects on eyewitness reports in morning and evening types

Our performance varies throughout the day as a function of alignment with our circadian rhythms. The current experiment tested whether similar performance patterns can be observed in eyewitness memory performance. One-hundred-and-three morning-type and evening-type participants watched a stimulus event, provided a free report and answered cued questions in the morning and the evening hours, respectively. We expected eyewitness reports to be more detailed and more accurate at participants’ circadian peaks than at circadian troughs. Contrary to our predictions, time of testing did not significantly affect quantity and accuracy of eyewitness statements. Future studies might investigate whether matching chronotype with time of day would be beneficial when encoding or retrieval conditions are suboptimal or when eyewitnesses are vulnerable.     

An event‐based magnetoencephalography study of simulated driving: Establishing a novel paradigm to probe the dynamic interplay of executive and motor function

Magnetoencephalography (MEG) is particularly well‐suited to the study of human motor cortex oscillatory rhythms and motor control. However, the motor tasks studied to date are largely overly simplistic. This study describes a new approach: a novel event‐based simulated drive made operational via MEG compatible driving simulator hardware, paired with differential beamformer methods to characterize the neural correlates of realistic, complex motor activity. We scanned 23 healthy individuals aged 16–23 years (mean age = 19.5, SD = 2.5; 18 males and 5 females, all right‐handed) who completed a custom‐built repeated trials driving scenario. MEG data were recorded with a 275‐channel CTF, and a volumetric magnetic resonance imaging scan was used for MEG source localization. To validate this paradigm, we hypothesized that pedal‐use would elicit expected modulation of primary motor responses beta‐event‐related desynchronization (B‐ERD) and movement‐related gamma synchrony (MRGS). To confirm the added utility of this paradigm, we hypothesized that the driving task could also probe frontal cognitive control responses (specifically, frontal midline theta [FMT]). Three of 23 participants were removed due to excess head motion (>1.5 cm/trial), confirming feasibility. Nonparametric group analysis revealed significant regions of pedal‐use related B‐ERD activity (at left precentral foot area, as well as bilateral superior parietal lobe: p < .01 corrected), MRGS (at medial precentral gyrus: p < .01 corrected), and FMT band activity sustained around planned braking (at bilateral superior frontal gyrus: p < .01 corrected). This paradigm overcomes the limits of previous efforts by allowing for characterization of the neural correlates of realistic, complex motor activity in terms of brain regions, frequency bands and their dynamic temporal interplay.     

Left Ventricular Dyssynchrony and Its Effects on Cardiac Function in Patients with Newly Diagnosed Hypertension

Objectives: Left ventricular (LV) systolic synchrony, defined as simultaneous peak contractions of corresponding cardiac segments, is well documented to be impaired in hypertension but its effect on LV function is not clear. The aim of this study was to assess the impacts of LV systolic dyssynchrony on LV function in newly diagnosed hypertensives. Methods: Forty-eight newly diagnosed hypertensive patients and 33 controls were enrolled. All study population underwent a comprehensive echocardiographic evaluation including tissue synchrony imaging. The time to regional peak systolic tissue velocity (Ts) in LV by 12 segmental models was measured and two parameters of systolic dyssynchrony were computed. Results: Baseline demographic characteristics were similar in both study groups. Dyssynchrony parameters prolonged in newly diagnosed hypertensive patients compared to controls: the standard deviation (SD) of 12 LV segments Ts (40.2 ± 21 vs. 26.2 ± 13.4, P = 0.003); the maximal difference in Ts between any 2 of 12 LV segments (123.3 ± 61.5 vs. 79.8 ± 37.9, P = 0.001). In multivariable analysis, Ts-SD-12 was found to be an independent predictor for systolic function (β=-0.29, P = 0.008). But, both diastolic and global functions were not independently related to Ts-SD-12. Conclusion: LV synchronization is impaired in newly diagnosed hypertensive patients. LV dyssynchrony is one of the independent predictors of systolic function in hypertensive patients.     

实时三维超声心动图评价扩张型心肌病左室收缩同步性的有效性研究

目的 探讨应用实时三维超声心动图(RT-3DE)评价扩张型心肌病(DCM)患者左室收缩同步性的可行性.方法 将24例扩张型心肌病患者和20例正常人行RT-3DE检查.应用QLAB定量分析软件对三维数据库进行评价,即左室16节段、6个基底段和6个中间段、6个基底段达收缩末最小容积时间的标准差(TmsvSD-16,12,6),达到最小收缩末容积的时间的最大差值(Tmsv-16,12,6Dif),经心率校正后值Tmsv-SD％和Tmsv-Dif％.结果 心肌病组的TmsvSD-16、Tmsv-16Dif及TmsvSD-16％Tmsv-16Dif％值均较正常对照组增加(P＜0.05).结论 RT-3DE能客观的评价扩张型心肌病患者左心室收缩同步性,TmsvSD-16％、Tmsv-16Dif％可作为评价左室收缩同步性的有效指标.     

Characterizing inter-limb synchronization after incomplete spinal cord injury: A cross-sectional study

BackgroundIndividuals with incomplete spinal cord injury (iSCI) demonstrate greater postural sway and increased dependency on vision to maintain balance compared to able-bodied individuals. Research on standing balance after iSCI has focused on the joint contribution of the lower limbs; however, inter-limb synchrony in quiet standing is a sensitive measure of individual limb contributions to standing balance control in other neurological populations. It is unknown if and how reduced inter-limb synchrony contributes to the poor standing balance of individuals with iSCI.Research questionHow does an iSCI affect inter-limb synchrony and weight-bearing symmetry in standing?MethodsEighteen individuals with non-progressive motor iSCI and 15 age- and sex-matched able-bodied individuals (M-AB) were included in the study. Participants stood in a standardized position on two adjacent force plates in eyes open and closed conditions for 70 s per condition. Net centre-of-pressure (COP) root mean square (RMS), net COP velocity, COP inter-limb synchrony (i.e. cross-correlation between left and right COP), and weight-bearing asymmetry (i.e. vertical force from each limb over total vertical force) were calculated. Muscle strength of the lower limbs was assessed with manual muscle testing.ResultsIndividuals with iSCI demonstrated reduced inter-limb synchrony when standing with eyes open and eyes closed, but did not differ to M-AB with respect to weight-bearing asymmetry. They also produced greater net COP RMS and velocity when compared to M-AB. Muscle strength of the two lower limbs demonstrated an overall asymmetry in individuals with iSCI.SignificanceIndividuals with iSCI demonstrated impaired balance control as evidenced by reduced inter-limb synchrony and greater COP RMS and velocity compared to M-AB individuals. This increased understanding of how balance control is impaired following iSCI may inform balance assessment and intervention for this population. Future work examining the association between inter-limb synchrony and the occurrence of falls in iSCI is warranted.     

Closed-Loop Neurofeedback of α Synchrony during Goal-Directed Attention

α Oscillations in sensory cortex, under frontal control, desynchronize during attentive preparation. Here, in a selective attention study with simultaneous EEG in humans of either sex, we first demonstrate that diminished anticipatory α synchrony between the mid-frontal region of the dorsal attention network and ventral visual sensory cortex [frontal-sensory synchrony (FSS)] significantly correlates with greater task performance. Then, in a double-blind, randomized controlled study in healthy adults, we implement closed-loop neurofeedback (NF) of the anticipatory α FSS signal over 10 d of training. We refer to this closed-loop experimental approach of rapid NF integrated within a cognitive task as cognitive NF (cNF). We show that cNF results in significant trial-by-trial modulation of the anticipatory α FSS measure during training, concomitant plasticity of stimulus-evoked α/θ responses, as well as transfer of benefits to response time (RT) improvements on a standard test of sustained attention. In a third study, we implement cNF training in children with attention deficit hyperactivity disorder (ADHD), replicating trial-by-trial modulation of the anticipatory α FSS signal as well as significant improvement of sustained attention RTs. These first findings demonstrate the basic mechanisms and translational utility of rapid cognitive-task-integrated NF.SIGNIFICANCE STATEMENT When humans prepare to attend to incoming sensory information, neural oscillations in the α band (8–14 Hz) undergo desynchronization under the control of prefrontal cortex. Here, in an attention study with electroencephalography, we first show that frontal-sensory synchrony (FSS) of α oscillations during attentive preparation significantly correlates with task performance. Then, in a randomized controlled study in healthy adults, we show that neurofeedback (NF) training of this α FSS signal within the attention task is feasible. We show that this rapid cognitive NF (cNF) approach engenders plasticity of stimulus-evoked neural responses, and improves performance on a standard test of sustained attention. In a final study, we implement cNF in children with attention deficit hyperactivity disorder (ADHD), replicating the improvement of sustained attention found in adults.