A comparative analysis of sensory visual evoked oscillations with visual cognitive event related oscillations in Alzheimer's disease

We compared visual evoked oscillatory responses of subjects with Alzheimer's disease (AD) (n = 22) to healthy elderly controls (n = 19) elicited by simple light stimuli. The visual evoked oscillatory responses in AD subjects without cholinergic treatment (n = 11) show significant differences (df = 2.38, F = 4.957, P = 0.012) from the controls and the AD subjects treated with a cholinesterase inhibitor (n = 11). Higher theta oscillatory responses in untreated AD subjects are seen on the electrode locations over bi-parietal and right occipital regions after simple light stimuli with less, if any, cognitive load. These changes were restricted to the theta frequency range only and are related to location, frequency bands and drug effects. In our previous work we observed that visual event related oscillations elicited after the visual stimuli with a higher cognitive load, i.e. an oddball target, display lower amplitudes: between controls and AD subjects in delta frequency band without a drug effect, over the left and mid-central region. These differences between the visual evoked oscillations and the visual event related oscillations imply that there are at least two different cognitive circuits that are activated upon visual stimuli in AD patients.     

焦虑症患者VEP及AEP临床研究

目的：观察焦虑症患者听觉诱发电位(AEP)及视觉诱发电位(VEP)的特点。方法：对30例符合CCMD-Ⅱ-R诊断标准的焦虑症患者进行VEP和AEP检查，并以30例正常人作对照。结果：VEP在Fz及Cz处的P2、P3波幅明显降低，在Cz处N1潜伏期延长；AEP在Cz及P2处的P2、P3波波幅明显降低，N1潜伏期延长，在Cz处P2潜伏期延长。结论：焦虑症患者的VEP、AEP有波幅降低，潜伏期延长。     

精神运动性癫痫患者脑诱发电位初步观察

目的研究脑诱发电位在精神运动性癫痫病人的应用。方法应用诱发电位仪对１６例精神运动性癫痫的听觉诱发电位（ＡＥＰ）、视觉诱发电位（ＶＥＰ）和听觉事件相关电位（听觉Ｐ３００）作了检测，并与正常对照组进行了比较。结果患者组波形变异大，潜伏期ＡＥＰ的Ｐ２、Ｐ３，ＶＥＰ的Ｎ１、Ｐ２以及Ｐ３００靶刺激的Ｐ２、Ｎ２均延迟，非靶刺激的Ｎ１前移。波幅ＡＥＰ的Ｐ２、ＶＥＰ的Ｐ２、Ｐ３降低，与正常对照组有显著性差异。结论ＢＥＰ技术可作为脑电图检查的一种补充手段，以便临床参考诊断此类病征。     

视觉、脑干听觉诱发电位对多发性硬化的诊断价值

目的 :探讨视觉诱发电位 (VEP)、听觉诱发电位 (BAEP)对多发性硬化 (MS)的诊断价值。方法 :对 30例临床诊断为MS的患者进行VEP、BAEP检测 ,并与正常对照组进行比较分析。结果 :MS患者VEP和BAEP的异常率分别为 73%和 6 0 %。异常中VEP有 6 8% ,BAEP有 78%的患者 ,临床有相应的症状 ;VEP 32 % ,BAEP 2 2 %的患者临床无相应症状。 5例MS患者在临床缓解期复查VEP、BAEP ,1例VEP、BAEP恢复正常 ,4例仍异常。结论 :VEP、BAEP检测对MS的诊断具有重要意义。     

Mechanism of caspase-3 activation during hypoxia in the cerebral cortex of newborn piglets

We have previously shown that the activity and the expression of caspase-9 and caspase-3 were increased during hypoxia in the cerebral cortex of newborn piglets. The present study was conducted to test the hypothesis that the hypoxia-induced activation of caspase-3 in the cerebral cortex of newborn piglets is mediated by caspase-9. Twenty-two newborn piglets were randomly assigned to four groups: normoxic (Nx), normoxic pretreated with a selective caspase-9 inhibitor, Z-Leu-Glu(OMe)-His-Asp(OMe)-Fluoromethyl ketone (Z-LEHD-FMK) (Nx + LEHD), hypoxic (Hx), and hypoxic pretreated with Z-LEHD-FMK (Hx + LEHD). Cerebral tissue hypoxia was confirmed biochemically by measuring ATP and phosphocreatine. Caspase-9 and -3 activities were determined spectrofluorometrically. The expression of caspase-9 and -3 proteins was measured by Western blot analysis using active enzyme specific antibodies. Cytosolic caspase-9 activity (nmol/mg protein/h) was 3.70 ± 0.40 in Nx, 3.56 ± 0.31 in Nx + LEHD (p = NS versus Nx), 4.99 ± 0.64 in Hx (p < 0.05 versus Nx), and 3.73 ± 0.80 in Hx + LEHD (p < 0.05 versus Hx, p = NS versus Nx). Cytosolic caspase-3 activity (nmol/mg protein/h) was 7.80 ± 1.17 in Nx, 8.15 ± 0.87 in Nx + LEHD (p = NS versus Nx), 13.07 ± 0.78 in Hx (p < 0.05 versus Nx), and 10.05 ± 2.09 in Hx + LEHD (p < 0.05 versus Hx) The density (OD × mm²) of active caspase-9 protein was 18.52 ± 1.89 in Nx, 20.53 ± 1.12 in Nx + LEHD (p = NS versus Nx), 32.36 ± 5.03 in Hx (p < 0.05 versus Nx), and 19.94 ± 3.59 in Hx + LEHD (p < 0.05 versus Hx, p = NS versus Nx). The density (OD × mm²) of active caspase-3 protein was 55.87 ± 8.73 in Nx, 55.69 ± 8.18 in Nx + LEHD (p = NS versus Nx), 94.10 ± 12.05 in Hx (p < 0.05 versus Nx), and 56.12 ± 14.56 in Hx + LEHD (p < 0.05 versus Hx, p = NS versus Nx). These data show that administration of a selective caspase-9 inhibitor, Z-LEHD-FMK, prior to hypoxia prevents the hypoxia-induced increase in caspase-3 activity and the expression of active caspase-3 protein. We conclude that the hypoxia-induced activation of caspase-3 during hypoxia in the cerebral cortex of newborn piglets is mediated by caspase-9.     

Orientation-Specific and Luminance Effects: Interocular Suppression of Visual Evoked Potentials in Man

The interocular transfer of orientation-specific effects was investigated using visual evoked potentials (VEPs). Monocular VEPs were obtained to either diffuse light or grids of 0° or 45° orientations flashed to one eye. The other eye continuously viewed either darkness, diffuse light or grids of 0°, 15°, 30°, or 45° orientations. Changing the continuous stimulus from darkness to diffuse light interocularly reduced the amplitude of a late VEP component (P200). Changing the orientation of the continuous stimulus primarily affected an earlier VEP component (N110). This interocular effect was orientation specific: the more similar the orientation of the flashed and continuously presented grids, the smaller the amplitude of the VEP components. The 1/2 bandwidths at 1/2 amplitude of the orientation tuning functions were 45° and 32° for the vertical and oblique test flashes respectively. This orientation-specific interocular suppression was discussed in terms of electrophysiological and psychophysical data indicating binocular orientation channels and the interactions among these channels.     

Lack of the cerebral peduncle involvement in a series of adult supratentorial AVM: A diffusion tensor imaging study

Congenital as arteriovenous malformation(AVM) is, most patients with AVM would be asymptomatic until adults. During the past 2 years, 23 cases of adult supratentorial AVM patients had DTI after admission. The region of interest was placed in the cerebral peduncle. Their FA value and fiber number was compared with those of cavernous malformation (CM) and tumor (glioma and meningioma). In the AVM group, there was no significant difference in FA of the cerebral peduncle (ipsilateral 0.758 ± 0.055 versus contralateral 0.755 ± 0.049; P > 0.05) and fiber number (319.6 ± 82.9 versus 304.7 ± 89.1; P > 0.05). In the CM group, FA of the cerebral peduncle on ipsilateral side (0.711 ± 0.092) was significantly lower than that of contralateral side (0.768 ± 0.043) (P < 0.01). Similar result was in fiber number of the CM group (251 ± 82.1 versus 307.3 ± 77.0; P < 0.05). In tumor group, FA of ipsilateral side (0.713 ± 0.084) was lower than that of contralateral (0.751 ± 0.052) without significant difference. There was no significant difference in fiber number between ipsilateral and contralateral sides in the tumor group (308.9 ± 112.4 versus 287.9 ± 62.4). Unlike non-AVM lesions (CM and tumor), FA value and fiber number of the ipsilateral cerebral peduncle is less influenced in the AVM group. The lack of the cerebral peduncle involvement indicates that there is plasticity of white matter in AVM.     

帕金森病患者视觉诱发电位地形图改变及意义

目的：探讨帕金森病（PD）患者视觉传导通路功能受累的可能性及视觉诱发电位（VEP）空间分布特征。方法：应用VEP-脑地形图对20例PD患者与24位正常人进行对比研究。结果：（1）PD患者P1、N2波潜伏期延长；（2）两眼间潜伏期差增大；（3）颅顶波幅值呈广泛性降低，以左半球为著。结论：PD患者视觉信息在时间和空间传导中均发生障碍，VEP-脑地形图可敏感地反映出这种改变，对PD的研究及临床诊断，疗效观察均有一定价值。     

Compartmental chest wall volume changes during volitional hyperpnoea with constant tidal volume in healthy individuals

Prolonged high-intensity ventilation is associated with the development of rapid shallow breathing with decreased end-inspiratory volumes of all chest wall compartments. During respiratory muscle endurance training using normocapnic hyperpnoea, tidal volume (V_T) is normally kept constant. The aim of this study was to investigate possible changes in muscle recruitment during constant-V_T hyperpnoea, to assess potential mechanisms related to rapid shallow breathing. Ten healthy subjects performed 1 h of normocapnic hyperpnoea at 70% of maximal voluntary ventilation. Chest wall volume changes were assessed by optoelectronic plethysmography. End-inspiratory (1.08 ± 0.18 versus 0.96 ± 0.27 l, p = 0.017) and end-expiratory volumes (−0.13 ± 0.15 versus −0.31 ± 0.19 l, p = 0.007) of the pulmonary ribcage decreased significantly and lung function and respiratory muscle strength were reduced (all p < 0.05). Since with forced, constant V_T only the inspiratory rib cage muscles were unable to sustain end-inspiratory volume of their compartment, inspiratory rib cage muscles are the most likely candidate responsible for the development of rapid shallow breathing.     

−1722T/C polymorphism (rs733618) of CTLA-4 significantly associated with systemic lupus erythematosus (SLE): A comprehensive meta-analysis

This study was to determine whether −318C/T (rs5742909), −1722T/C (rs733618) and −1661A/G (rs4553808) of Cytotoxic T-lymphocyte antigen-4 (CTLA-4) are associated with systemic lupus erythematosus (SLE). The meta-analysis for −318C/T (rs5742909) included 1163 cases and 1520 controls, for −1722T/C (rs733618) included 1016 cases and 1078 controls, and for −1661A/G (rs4553808) included 637 cases and 774 controls. For −318C/T (rs5742909), statistically significant differences were not noted between cases and controls {fixed/random: OR: 1.103, 95% CI: (0.907–1.341), p = 0.326}. For −1661A/G (rs4553808), also no significant difference existed {fixed: OR: 1.024, 95% CI: (0.843–1.244), p = 0.812; random: OR: 1.077, 95% CI: (0.780–1.300), p = 0.958}. But −1722T/C (rs733618) was significantly associated with SLE both in allele {fixed: OR: 0.699, 95% CI: (0.602–0.811), p = 0.000; random: OR: 0.748, 95% CI: (0.565–0.990), p = 0.042} and in genotype {CC/(CT + TT)} meta-analysis {OR: 0.422, 95% CI: (0.297–0.598), p = 0.000}. Also, we subdivided the −1722T/C group (rs733618) into Asia and Mixed subgroups, in Asia subgroup, the SNP was significantly associated with SLE {fixed: OR: 0.628, 95% CI: (0.528–0.746), p = 0.000; random: OR: 0.641, 95% CI: (0.470–0.875), p = 0.005}, in the Mixed subgroup, this polymorphism was not associated with SLE {fixed: OR: 0.946, 95% CI: (0.707–1.267), p = 0.711; random: OR: 0.973, 95% CI: (0.606–1.560), p = 0.908}. These results suggest that there is evidence of association between the CLTA-4 and SLE, especially −1722T/C polymorphism (rs733618).     

眼挫伤后视力损害患者视觉诱发电位分析

目的:探讨视觉诱发电位(VEP)在评价挫伤后视力损害中的价值。方法:对74例挫伤性视力损害患者进行图形翻转刺激VEP测定,并与自体健侧眼和正常对照组进行比较。结果:74例患者中,单眼挫伤57例,双眼挫伤17例,共91眼受伤,受伤眼均有不同程度视力损害。VEP检查结果:91 眼中波形不典型者5眼(6％);P100波幅下降异常者54眼(59％);P100潜伏期延长者23眼(25％)。其中单纯潜伏期延长12眼(13％);单纯波幅下降异常43眼(47％);潜伏期延长伴波幅下降者11眼 (12％),总异常66眼,异常率为73％。所有挫伤后视力损害者,与自体健侧服和正常对照组比较,P100 潜伏期延长和波幅降低,差异均有显著意义(P<0．01)。结论:VEP为挫伤性视力损害的视功能评价、临床早期诊断、预后评估以及伤残鉴定提供了重要的客观依据。     

LRRK2 variant associated with Alzheimer's disease

Overlapping neurodegenerative pathologies (including Alzheimer's disease, AD) have been described in Parkinson's disease (PD) patients with leucine-rich repeat kinase-2 (LRRK2) mutations. We analyzed a LRRK2 PD (R1628P) risk variant in a group of 885 subjects comprising of AD and controls. The frequency of the R1628P allele was higher in AD compared to controls (3.5% vs. 1.6%, OR 2.3, 95 CI 1.2-4.4, p = 0.018). In vitro, the mean percentage of apoptosis and cell death observed for the R1628P transfected human cell lines was higher compared to wild type 21.8 ± 1.9, vs. 17.1 ± 1.3, p < 0.05, 30.2 ± 2.2 vs. 25.7 ± 1.3, p < 0.05). The LRRK2 R1628P variant increases the risk of AD in our population and our in vitro findings suggest that it is a functional variant and predisposes to apoptosis.     

Primary somatosensory evoked magnetic fields elicited by sacral surface electrical stimulation

To explore the brain response to sacral surface therapeutic electrical stimulation (SSTES) for the treatment of refractory urinary incontinence and frequent micturition, evoked magnetic fields were measured in six healthy males. Electrical stimuli were applied between bilateral surface electrodes over the second through fourth posterior sacral foramens with intensity just below the pain threshold. Somatosensory evoked magnetic fields (SEFs) for the bilateral median (MN) and posterior tibial nerves (PTN) were also measured for the comparison. Sources of the early SEF peaks were superimposed on individual magnetic resonance images. The first peak latency for sacral stimuli, M30, occurred at 30.2 ± 0.8 ms (mean ± standard deviation, N = 6), with shorter latency than those for PTN stimulus (39.3 ± 1.4 ms, N = 12) and longer latency than those for MN stimulus (21.0 ± 0.9 ms, N = 12). The second peak latency for sacral stimuli, M50, occurred at 47.2 ± 2.9 ms (N = 6). Both M30 and M50 peaks showed a single dipole pattern over the vertex in the isofield maps. The equivalent current dipoles of M30 and M50 were both estimated near the medial end of the central sulcus with approximately posterior current direction. These results suggest that the sacral M30 and M50 are responses from the primary somatosensory cortex. The relatively long time lag between the onset and peak of M30 suggests that SSTES directly affects both the cauda equina and cutaneous nerve of the sacral surface.     

Stimulus Intensity Expectation and Visual Evoked Brain Potentials

In a sample of 32 adult subjects, we examined the relationship between amplitude measures of the visual evoked potential (VEP) and a subject's expectation that a stimulus would be either brighter or dimmer than the others in a series. It was found that when subjects expected a bright light flash, the VEP waveform changed in the direction associated with a stimulus intensity increase even though no actual intensity change occurred. Conversely, when subjects expected a dim light flash, the VEP waveform changed in the direction associated with a stimulus intensity decrease even though no actual intensity change occurred. The amplitude changes to the expected stimulus intensities occurred in specific VEP peaks and were related to the position of the stimulus in the sequence.     

Hand dominancy—A feature affecting sensitivity to pain

Hand dominancy (i.e. handedness) is a factor that should be considered for further characterizing individual variations in sensitivity to pain. The aim of the present study was to examine the contribution of handedness and gender to sensitivity to tonic cold pain in healthy subjects. Participants were 109 healthy volunteers (52 males and 57 females), of whom 65 were right-handed and 44 left-handed. Subjects were exposed to the cold pressor test (1 °C) for both hands while measuring the cold pain threshold, intensity, and tolerance. No significant differences were found in pain threshold or intensity between the right versus the left hands among either the right-handed or the left-handed subjects. However, among the right-handed subjects only, cold pain tolerance was significantly longer in the right hand than in the left hand (32.9 ± 5.1 s vs. 27.0 ± 4.2 s, respectively; p = 0.018). Significant differences were found between males and females in pain threshold, but not in pain intensity or tolerance, either when their right or left hand was tested (p = 0.027 and p = 0.009, respectively). Analyzing pain perception by handedness and gender revealed that the right-handed males were less sensitive to pain in their right versus their left hand, as determined by lower pain intensity (p = 0.031) and longer tolerance (p = 0.047). No significant differences were found among the left-handed males or among the females. The results provide further evidence that handedness is one vital feature that should be considered more often when designing a psychophysical study. This may lead towards improving the translation of laboratory research findings to the clinical setting.     

Somatosensory amplification and its relationship to somatosensory, auditory, and visual evoked and event-related potentials (P300)

Somatosensory amplification refers to the tendency to experience benign and ambiguous somatic sensation as intense, noxious, and disturbing. The construct is helpful in assessing the perceptual style of a variety of somatizing conditions, but there is no human study clarifying the effects of neurological function on somatosensory amplification. The present study examines the relationship between somatosensory amplification and different types of evoked potentials. In 33 healthy volunteers (mean age 24 years, 18 men), latencies and amplitudes were recorded using the following parameters: short-latency somatosensory, brainstem-auditory, and visual evoked potentials (SSEP, BAEP, and VEP, respectively) and auditory event-related potentials (ERP). All subjects completed questionnaires for the Somatosensory Amplification Scale (SSAS), 20-item Toronto Alexithymia Scale (TAS-20), and Profile of Mood State (POMS). The SSAS scores were significantly associated with the P200 latency (p=0.020) and P300 amplitude of ERP (p=0.041), controlling for the significant effect of the TAS and POMS depression and tension-anxiety scales. The SSEP, BAEP, and VEP latencies or amplitudes were not statistically significant (all p>0.05). When the subjects were divided into high and low SSAS groups based on the median of the SSAS scores, the P300 amplitude of ERP significantly discriminated the two groups (p=0.023) by multiple logistic regression analysis. Although the findings should be viewed as preliminary because of the small sample size, somatosensory amplification appears to reflect some aspects of long-latency cognitive processing rather than short-latency interceptive sensitivity from the viewpoint of encephalography.     

Cortical sources of the respiratory-related evoked potential

The respiratory-related evoked potential (RREP) is increasingly used to study the neural processing of respiratory signals. However, little is known about the cortical origins of early (Nf, P1, N1) and later RREP components (P2, P3). By using high-density EEG, we studied cortical sources of RREP components elicited by short inspiratory occlusions in 18 healthy volunteers (6 female, mean age 20.0 ± 1.8 years). Topographical maps for Nf and P1 showed bilateral maximum EEG voltages over the frontal and centro-parietal cortex, respectively. Cortical source analyses (minimum-norm estimates) in addition to topographical maps demonstrated bilateral sensorimotor cortex origins for N1 and P2 which were paralleled by an additional frontal cortex source (p's < 0.05). The source of the P3 was located at the parietal cortex (p < 0.05). The results support previous findings on the cortical sources of early RREP components Nf, P1 and N1 and demonstrate the cortical sources of later RREP components P2 and P3.     

Serum paraoxonase and arylesterase activities in patients with pulmonary tuberculosis

Background: The aim of the present study was to determine serum paraoxonase and arylesterase activities in tuberculosis, nontuberculosis pulmonary disease and healthy subjects. Materials and methods: In this case-control study we determined the serum paraoxonase and arylesterase activities in 36 patients with pulmonary tuberculosis, 38 nontuberculosis pulmonary disease and 49 healthy controls. Results: The results showed that serum paraoxonase (PON) activity was significantly lower in patients with pulmonary tuberculosis (61.10 ± 51.62 IU/L) than healthy controls (98.79 ± 68.79 IU/L) (p < 0.05). In addition we found that the level of PON activity was significantly lower in patients with nontuberculosis pulmonary disease (67.49 ± 47.88 IU/L) than normal individuals (p < 0.05). There was no significant differences regarding PON activity between patients with pulmonary tuberculosis and nontuberculosis pulmonary disease (p > 0.05). The arylesterase activity was significantly lower in patients with pulmonary tuberculosis than nontuberculosis pulmonary disease and normal subjects (p < 0.05). Discussion: The lower paraoxonase and aryesterase activities in pulmonary tuberculosis patients compared to healthy subjects might be due to imbalance of oxidant/antioxidant systems in pulmonary tuberculosis patients which needs more clarification.     

Deficits in the visual evoked potentials of cats as a result of visual deprivation

Summary Visual evoked potentials in response to contrast reversal of grating patterns were used as a measure of visual function in normal and visually deprived cats. In cats which had been dark reared from birth (BD cats) there was a characteristic change in VEP waveform from normal, for both eyes and for all spatial frequencies of testing stimulus. In cats which had one eye sutured from the age of one week (MD cats), the VEP from the deprived eye was smaller for contrast reversal of coarse patterns. Kittens given only restricted periods of monocular exposure gave VEPs which resembled the pathological responses of the BD cats. However, the amplitudes of response were larger for the more experienced eye at higher spatial frequency. This work reinforces the idea that two factors govern cortical development: competition and experience. Lack of sufficient visual experience leads to severe intracortical pathology.     

Effect of chronic activation of 5-HT3 receptors on 5-HT3, 5-HT(1A) and 5-HT(2A) receptors functional activity and expression of key genes of the brain serotonin system

The dopamine D3 receptor gene (DRD3) is considered being one of the candidate genes contributing to the development of tardive dyskinesia (TD). In a recent meta-analysis with mixed ethnicities, only a barely positive association was found between the functional DRD3 Ser9Gly polymorphism and TD in patients with schizophrenia (OR = 1.17; 95% CI: 1.01-1.37; p = 0.041). To further evaluate the controversial association between the polymorphism and TD using only Japanese subjects, we tested the association in a case-control design. We also conducted a meta-analysis including 8 studies with 3 East Asian populations (Japanese, Chinese, and Korean). In our Japanese case-control sample (43 with TD/157 without TD), we found no association between the DRD3 Ser9Gly polymorphism in schizophrenia and TD (genotype: p = 0.92; allele: p = 1.00). Furthermore, no significant difference in the mean AIMS score among the three genotypic groups was observed in our sample. The meta-analysis comprising 1291 East Asian subjects also showed no association between the polymorphism and TD; the Mantel-Haenszel pooled OR for TD among carriers of the DRD3 Ser9Gly of the eight Asian studies was 0.94 (95% CI: 0.78-1.12). Overall, our results suggest that the DRD3 Ser9Gly polymorphism may not confer susceptibility to TD in East Asian populations. Given that the Ser9Gly variant may play a putative role in the DRD3 function, further studies on the DRD3 are warranted.