连续心算时脑电相干幅谱的反应特点

目的：分析心算时不同脑区之间各频率脑电活动的同步性特点。 方法：于2004—03／06对20名中国农业大学在校大学生或研究生（正常被试者）在安静及对数字声音信号进行连加心算时9个脑区之间的相干幅谱进行比较研究。 结果：20人均进入结果分析。①额区和中线部位为高同步区，与后联合区对应的后脑区为低同步区。②与安静状态相比，心算时20Hz以上的高频活动同步性显著下降，且以左后脑区最明显，θ，α等低频活动的同步性增强，特别是额区和中央脑区。 结论：在进行认知活动时，左、右脑之间的相互作用可通过脑电的相干幅值变化反映出来。     

连续心算时脑电相干幅谱的反应特点

目的:分析心算时不同脑区之间各频率脑电活动的同步性特点。方法:于2004-03/06对20名中国农业大学在校大学生或研究生(正常被试者)在安静及对数字声音信号进行连加心算时9个脑区之间的相干幅谱进行比较研究。结果:20人均进入结果分析。①额区和中线部位为高同步区,与后联合区对应的后脑区为低同步区。②与安静状态相比,心算时20Hz以上的高频活动同步性显著下降,且以左后脑区最明显,θ,α等低频活动的同步性增强,特别是额区和中央脑区。结论:在进行认知活动时,左、右脑之间的相互作用可通过脑电的相干幅值变化反映出来。     

Localization of cortical tissue optical changes during seizure activity in vivo with optical coherence tomography

Optical coherence tomography (OCT) is a high resolution, minimally invasive imaging technique, which can produce depth-resolved cross-sectional images. In this study, OCT was used to detect changes in the optical properties of cortical tissue in vivo in mice during the induction of global (pentylenetetrazol) and focal (4-aminopyridine) seizures. Through the use of a confidence interval statistical method on depth-resolved volumes of attenuation coefficient, we demonstrated localization of regions exhibiting both significant positive and negative changes in attenuation coefficient, as well as differentiating between global and focal seizure propagation.OCIS codes: (110.4500) Optical coherence tomography, (170.3880) Medical and biological imaging, (100.2960) Image analysis     

Role of amplitude-integrated electroencephalography in neonates with cardiovascular compromise

Background

Neonates with congenital heart disease (CHD) and persistent pulmonary hypertension of the newborn (PPHN) represent conditions with increased risk of abnormal neurologic outcome. The role of aEEG in disorders where cerebral perfusion/oxygenation is affected by cardiac or pulmonary disease is unknown.

Objective

The aim of the study was to characterize amplitude-integrated electroencephalography (aEEG) traces in nonasphyxiated neonates with cardiorespiratory compromise secondary to PPHN or CHD.

Design/Methods

Three hundred sixty-three aEEG records (June 2004-November 2006) were reviewed to identify neonates with a diagnosis of isolated CHD or PPHN. Clinical course, critical interventions, and neurodiagnostic investigation data were collected. The aEEG traces were reviewed by a single blinded expert and classified according to background activity (normal, moderate, or severely abnormal) and presence of seizures. The frequency of abnormal aEEG in both groups and its relationship to recognized markers of abnormal neurologic outcome (electrophysiology [EP] testing and neuroimaging [ultrasound (USS), computerized tomography, and magnetic resonance imaging] was studied.

Results

Thirty neonates (PPHN [n = 20], CHD [n = 10]) were reviewed at a mean gestation of 39.2 ± 1.1 weeks and weight of 3375 ± 565g. Neonates with PPHN had lower Apgar scores at 1-minute (P = .02) and were significantly more likely to require inotropic support (P < .001), inhaled nitric oxide (P = .001), or surfactant (P = .01). An abnormal aEEG was found in 15 (50%) babies, but rates did not differ between CHD (n = 6) and PPHN (n = 9). The rates of abnormal composite neurologic outcome (2/3 of abnormal EP, neuroimaging, or neurologic examination) were significantly higher in neonates with abnormal aEEG. An abnormal magnetic resonance imaging was seen in 4 of 5 neonates with abnormal aEEG.

Conclusions

The risk of abnormal aEEG is high in sick neonates with PPHN or complex CHD. Prospective evaluation of the relationship between aEEG recordings in these disorders and acute cardiorespiratory physiology, comprehensive neuroimaging, and long-term patient outcomes is needed.     

躯体焦虑性抑郁症的睡眠脑电图改变

目的探讨躯体焦虑性抑郁症病人的睡眠脑电图改变。方法对6例躯体焦虑性抑郁症(躯体焦虑组)、12例非躯体焦虑性抑郁症(非躯体焦虑组)和10例正常受试者(对照组)检测了睡眠脑电图。结果非躯体焦虑组的快眼动(rapideyemove,REM)活动量、强度和密度均比对照组显著为高[分别为(112±41)%vs(72±18)%;(34±14)%vs(19±4)%,(188±56)%vs(124±19)%,均P<0.05]。躯体焦虑组的REM睡眠时间[(36±20)min]比非躯体焦虑组[(63±22)min]及对照组[(60±17)min]的显著为短(P<0.05)。结论非躯体焦虑性抑郁症病人的REM活动量、强度和密度增加,躯体焦虑性抑郁症的REM睡眠时间缩短。     

Intrinsic correlations of electroencephalography rhythms with cerebral hemodynamics during sleep transitions

To examine the correlation between electroencephalography fluctuations (EEGF) and cerebral hemodynamics during sleep after eliminating influences from cardiovascular activity, we simultaneously measured EEGF, the cerebral hemoglobin concentration change, and mean arterial blood pressure (MAP) during the sleep of healthy human adults. The cerebral hemoglobin concentration change was measured at 88 positions covering the whole head, by optical topography. We extracted the intrinsic correlation between EEGF and the cerebral hemoglobin concentration change without MAP contributions through cross-correlation and partial correlation analyses considering time lags. We found that increases in the power of the alpha rhythm in EEGF were correlated with increases in oxygenated hemoglobin (oxy-Hb) and decreases in deoxygenated hemoglobin (deoxy-Hb) and that increases in the power of the sigma rhythm in EEGF were correlated with decreases in oxy-Hb and increases in deoxy-Hb. The former correlations tended to appear in the transition from sleep stage 2 to sleep stage 1, and the latter correlations tended to appear in the transition from sleep stage 1 to sleep stage 2. The former correlations were found in the inferior frontal and middle temporal gyri and the latter correlations were found in the superior frontal, middle frontal, and angular gyri.     

Correlation of intraoperative electroencephalography with neurologic deficit after carotid endarterectomy.

In an attempt to prevent morbidity and mortality in carotid endarterectomy, we monitored 47 operations with intraoperative EEG to determine which patients should have a shunt during endarterectomy. The EEG was recorded for up to five minutes during test carotid cross-clamping. When EEG asymmetry between the cerebral hemispheres occurred, the clamp was immediately removed. A shunt was used in all patients who had EEG asymmetry. In the absence of EEG asymmetry, no shunt was used. Of the 38 patients with no EEG asymmetry intraoperatively, one patient had transient deficits postoperatively. Electroencephalographic asymmetry occurred in nine patients during test carotid cross-clamping. Postoperatively, five of these shunted patients awakened neurologically intact and four patients had transient deficit. When the EEG was normal and no shunt was used, patients did well; when the EEG was abnormal and a shunt was used, there was a high incidence of transient neurologic deficit.     

脑电反馈治疗儿童注意缺陷多动障碍的疗效

背景脑电生物反馈治疗注意缺陷多动障碍(attention defici thyperactivity,ADHD)逐渐受到关注,但听觉和视觉注意分类研究报告较少.目的探讨脑电反馈治疗ADHD的有效性.设计随机、治疗前后自身对照研究.地点和对象将南京脑科医院儿童心理卫生门诊符合美国精神障碍诊断与统计手册第4版标准的30例ADHD儿童作为研究对象.干预由研究组成员对研究对象进行脑电生物反馈治疗,分别于治疗开始前、训练20次及40次后用整合视听连续执行测试(integrated visual and auditory continuous performance test,IVA-CPT)对患儿评定.主要观察指标综合反应控制商数和综合注意力商数.结果经过20次训练,息儿综合反应控制商数由87.38±15.7l,上升到98.56±10.78(t=4.59,P＜0.01),综合注意力商数由70.38±16.22,上升到88.94±16.37(t=4.68,P＜0.01);经过40次训练,患儿综合反应控制商数上升到107.00±8.43(t=5.38,P＜0.01),综合注意力商数上升到104.56±12.67(t=8.76,P＜0.01),与训练前相比,各脑电反馈商数均有显著改善(P＜0.01).结论脑电反馈治疗对ADHD的疗效肯定,对有明显注意缺陷患儿训练时间要比多动一冲动为主患儿训练时间为多.     

Source cancellation profiles of electroencephalography and magnetoencephalography

Recorded electric potentials and magnetic fields due to cortical electrical activity have spatial spread even if their underlying brain sources are focal. Consequently, as a result of source cancellation, loss in signal amplitude and reduction in the effective signal-to-noise ratio can be expected when distributed sources are active simultaneously. Here we investigate the cancellation effects of EEG and MEG through the use of an anatomically correct forward model based on structural MRI acquired from 7 healthy adults. A boundary element model (BEM) with four compartments (brain, cerebrospinal fluid, skull and scalp) and highly accurate cortical meshes (~ 300,000 vertices) were generated. Distributed source activations were simulated using contiguous patches of active dipoles. To investigate cancellation effects in both EEG and MEG, quantitative indices were defined (source enhancement, cortical orientation disparity) and computed for varying values of the patch radius as well as for automatically parcellated gyri and sulci. Results were calculated for each cortical location, averaged over all subjects using a probabilistic atlas, and quantitatively compared between MEG and EEG. As expected, MEG sensors were found to be maximally sensitive to signals due to sources tangential to the scalp, and minimally sensitive to radial sources. Compared to EEG, however, MEG was found to be much more sensitive to signals generated antero-medially, notably in the anterior cingulate gyrus. Given that sources of activation cancel each other according to the orientation disparity of the cortex, this study provides useful methods and results for quantifying the effect of source orientation disparity upon source cancellation.     

Diagnosis of oral precancer with optical coherence tomography

A procedure for computer analyzing an optical coherence tomography (OCT) image of normal and precancerous oral mucosae is demonstrated to reasonably plot the boundary between epithelium (EP) and lamina propria (LP) layers, determine the EP thickness, and estimate the range of dysplastic cell distribution based on standard deviation (SD) mapping. In this study, 54 normal oral mucosa, 39 oral mild dysplasia, and 44 oral moderate dysplasia OCT images are processed for evaluating the diagnosis statistics. Based on SD mapping in an OCT image, it is found that the laterally average range percentages of 70% SD maximum level in the EP layer is a reasonably good threshold for differentiating moderate dysplasia from mild dysplasia oral lesion based on the OCT image analysis. The sensitivity and specificity in diagnosis statistics can reach 82 and 90%, respectively.