Choice of the feference for EEG mapping in the newborn: An initial comparison of common nose reference,average and source derivation

Summary The instantaneous amplitude of different EEG patterns found in a 36 week newborn baby were mapped by isopotential display, using 3 different references. We found that in certain cases, the nose reference recalculated average and source derivations give the same results. If the different EEG activities on the skull have too an high amplitude, and are not in phase opposition, the average reference differs from the zero potential of the common reference. In this case, the nose may be a better reference. However, it is possible that under other conditions high amplitude activity contaminates the nose, rendering the other references as better choices. From these preliminary results, we recommend the simultaneous display of maps obtained with the different references, and the comparison of the maps with the tracings for topographic studies in babies. It is absolutely necessary to record at least two polygraphic derivations to be able to recognize the sleep stages in which the analyses were performed. The eyes movement lead lets us to see if the EEG activity contaminates the face with multiple displays. It is then possible to decide which reference system is most appropriate.This study was supported by a grant from the University of Rouen, and realized with the help of the Rouen University Hospital. The authors wish to thank the Neonatal care unit (Professor C. Fessard) for the children, C. Berland for the recordings, G. Sainton and E. Dreano for their technical assistance, and J. Sanctot for her secretarial capabilities.     

Source modelling of the rolandic focus

Summary In rolandic epilepsy, consideration of the stereotyped ictal symptomatology suggests that the epileptic zone is likely to be in the same cortical structure in different patients. Routine EEG tracings of the interictal spike activity suggests a deep Sylvian fissure location. On the basis of the predominantly tangential potential field at the peak spike negativity seen in this group of patients, the inferior bank of the Sylvian fissure appears to be a good candidate. Without invasive studies, little refinement to this rather imprecise localization can be made as there is neither neurologic deficit nor lesion to provide a marker on radiological imaging. However, the application of source modelling technique using a simple single-dipole spherical head model has resulted in improved understanding of the generator behaviour, and facilitated the generation of new ways of analyzing spikes (e.g., stability index). Review of newer quantitative approaches including matrix and singular value decomposition of the dataset, spatial-temporal constrained source estimates etc. suggest other fruitful approaches. At least in some patients with partial epilepsy, the source characteristics of interictal scalp spikes appear to contain information of the ictal generator. Under certain circumstances, such derived information which is not otherwise available from routine electrophysiology may influence clinical management and prognosis. This is an additional bonus to the primary objectives of quantification and data reduction.     

四角融合术后腕关节稳定性的衡量指标

目的提出衡量腕关节四角融合术后融合体稳定性的指标,探讨术后如何改善腕功能。方法12具新鲜尸体前臂标本,男8具,女4具,左右各6肢,模拟行四角融合术后,固定于腕关节动力学测试仪上,模拟腕关节的掌屈、背伸、尺倾、桡倾等运动,运动前后摄腕关节正、侧位X线片,测量并观察头月角(α)、桡月角(β)、头月正位角(θ)、融合体高度(H)和融合体宽度(W)的变化,并行统计学分析。结果腕关节由运动前中立位至掌屈50°时,α、β、H值与运动前相比,差异均有统计学意义(P<0.01);背伸至40°时,α、β、H值与运动前相比,差异有统计学意义(P<0.01)。腕关节由中立位至桡倾15°时,θ与W与运动前比较,差异有统计学意义(P<0.05);至尺倾25°时,θ与W的运动前比较,差异有统计学意义(P<0.05)。结论头月角、桡月角、头月正位角、融合体高度和融合体宽度等指标可用于衡量四角融合术后融合体的稳定性。     

Long-term neurite orientation on astrocyte monolayers aligned by microtopography

After spinal cord injury neuronal connections are not easily re-established. Success has been hampered by the lack of orientation of neurites inside scar tissue and a lack of neurites crossing out of the site of injury. Oriented scaffolds in biodegradable polymers could be an excellent way to support both the orientation of neurites within the injury site as well as aiding their crossing out of the lesion. To establish the validity of using grooved micro-topography in polycaprolactone in combination with glia we have studied the long-term (3 weeks) orientation of neuronal cells on monolayers of astrocytes on the top of grooved topographies of various dimensions. We find that neurites are significantly aligned by groove/ridge type topographies which are “buried” under a monolayer of astrocytes for up to 3 weeks. This alignment is significantly lower than that of neurites growing directly on the topography, but these neurons do not survive on the poly-l-lysine coated polymer for more than a week. The alignment of neurites on the astrocyte layer to the underlying topography decreases over time, and with groove width. Topographies with 12.5 or 25 μm lateral dimension appear optimal for the long-term alignment and can support myelination. We have shown for the first time that micro-topography can act through an overlaid astrocyte layer and results in aligned neurites in long-term culture and that these can be myelinated by endogenous oligodendrocytes.     

Equivalent dipole estimation of spontaneous EEG alpha activity: two-moving dipole approach

A method of estimating equivalent moving and fixed dipoles from the scalp-recorded EEG alpha waves, with the realistic geometry of the head taken into account, is presented. Twenty-one silver electrodes were used to collect spontaneous EEG alpha waves on the scale. Four models, the single-moving dipole model, the single-fixed dipole model, the two-moving dipole model and the two-fixed dipole model were applied to approximate the EEG alpha field on the scalp. The algorithm, based on a least-squares fit for estimating the moving and the fixed dipoles by using a realistically shaped head model, is described. The numerical accuracy of the algorithm is also evaluated by a computer simulation. It is found that the spontaneous EEG alpha activity observed on the scalp can be represented by two equivalent moving dipoles, simultaneously located separately in the occipital regions of the right and the left hemisphere, at a depth of 4–6 cm beneath the scalp, with a goodness-of-fit of up to 97 per cent for all subjects examined. The excellent fit of the two-moving dipole model to the EEG human alpha activity is also compared with the single-dipole fit.     

中耳炎手术中面神经定位和辨认的临床研究

目的探讨中耳炎手术中面神经的定位和辨认。方法回顾性分析2008年1月～2010年12月185例行开放式乳突根治术或加鼓室成形术的慢性化脓性中耳炎及胆脂瘤中耳炎患者的手术资料,对术中面神经探查定位及辨认方法进行分析总结。结果①185例中,面神经探查发现58例面神经裸露;②面神经鼓室段定位标志为匙突、齿突、砧骨短突,185例中33例匙突消失,25例齿突遭到破坏,19例砧骨短突破坏或移位;乳突段定位标志为水平半规管、二腹肌脊,185例中12例水平半规管遭破坏,14例二腹肌脊被破坏;33例鼓索神经变异;③面神经与肉芽组织的关系为肉芽组织覆盖于神经表面78例,肉芽包裹神经47例,肉芽组织来自于面神经本身24例。结论中耳炎手术中面神经的定位主要根据相对固定的砧骨、水平半规管、匙突等结构,当这些结构遭破坏或观察不清时,应联合多个标志综合判断,提高面神经定位的成功率。     

Life-span changes in P3a

The relationship of visual P3a to age was investigated in a life-span sample. The aims of the study were (1) to assess to what extent P3a, relative to P3b, decreases with increasing age; (2) To assess at which recording sites the relationship between P3a and age is strongest; (3) to investigate whether the relationship between P3a and age is best described as linear or nonlinear. One hundred and three well-functioning adults, 20-92 years old, were given a health interview, a battery of neuropsychological tests, and performed a visual three-stimuli oddball ERP task yielding both a P3a and a P3b. P3a and age was moderately correlated, with coefficients reaching.53 (Cz) and -.52 (Pz) for latency and amplitude, respectively. P3b was to a much lesser extent related to age. Generally, the age-P3a relationship was strongest at midline and central electrodes. Finally, the relationship between age and P3a was best described as linear. P3a seems selectively more impaired with age than P3b, but this impairment seems less pronounced at Fz than at Cz and Pz. There is a need for complex theoretical integration of these and previous findings.     

Factors affecting exposure to nicotine and carbon monoxide in adult cigarette smokers

Exposure to cigarette smoke among smokers is highly variable. This variability has been attributed to differences in smoking behavior as measured by smoking topography, as well as other behavioral and subjective aspects of smoking. The objective of this study was to determine the factors affecting smoke exposure as estimated by biomarkers of exposure to nicotine and carbon monoxide (CO). In a multi-center cross-sectional study of 3585 adult smokers and 1077 adult nonsmokers, exposure to nicotine and CO was estimated by 24 h urinary excretion of nicotine and five of its metabolites and by blood carboxyhemoglobin, respectively. Number of cigarettes smoked per day (CPD) was determined from cigarette butts returned. Puffing parameters were determined through a CreSS® micro device and a 182-item adult smoker questionnaire (ASQ) was administered. The relationship between exposure and demographic factors, smoking machine measured tar yield and CPD was examined in a statistical model (Model A). Topography parameters were added to this model (Model B) which was further expanded (Model C) by adding selected questions from the ASQ identified by a data reduction process. In all the models, CPD was the most important and highest ranking factor determining daily exposure. Other statistically significant factors were number of years smoked, questions related to morning smoking, topography and tar yield categories. In conclusion, the models investigated in this analysis, explain about 30-40% of variability in exposure to nicotine and CO.     

弱视斜视临床与发病机理的研究

本文报告了弱视931例(1332只眼)的远期疗效,结果表明视力提高与年龄、弱视深度、弱视类型等因素有明显关系。治愈的弱视患者中有81.07％建立立体视,弱视深度与体视有关,斜视性弱视获立体视率明显低于屈光不正和屈光参差两组。体视建立随年龄增长而逐渐发育。弱视复发是治疗中的一个重要问题,随访3年以上者无1例复发。同时在国内外首次3年治愈的随访期限。用多导视诱发电位地形图的研究结果提示:(1)内斜弱视的弱视眼鼻侧视网膜呈抑制现象;(2)恒定性外斜弱视颞侧视网膜抑制;(3)间歇性外斜弱视和屈光参差弱视眼未见半侧视网膜抑制;(4)内斜弱视眼对侧眼为非“正常眼”。     

合谷穴的局部解剖学研究

目的:为临床合谷穴针刺、穴位注射提供解剖学参考资料。方法:在100只成人手标本上解剖观测合谷穴局部。结果:合谷穴直刺进针时,针尖穿经层次由浅至深依次为皮肤、皮下组织、第一骨间背侧肌、拇收肌横头。拇指呈伸位时,针体经手背合谷穴皮肤至第一骨间背侧肌掌面的组织厚度是1.26±0.46 cm,至拇收肌掌面的组织厚度是2.38±0.34 cm,该厚度均超过合谷穴手背至手掌面皮肤组织厚度的一半。桡动脉末端位于针体近侧端,皮肤进针点与桡动脉末端穿第一骨间背侧肌入肌点的距离是3.14±0.22 cm。掌深弓亦位于针体的近侧端,伴尺神经深支走行,穿拇收肌后与尺神经深支终末段逐渐分开,行向掌背近侧端与桡动脉末端相接。针尖刺中掌深弓时,针体与掌背平面所成的远侧角最大为28.3±4.5°。尺神经深支终末段穿拇收肌横头与拇收肌斜头之间入拇收肌后间隙,并在此间隙内发出各肌支。结论:合谷穴针刺时,拇指应呈伸位,直刺进针,深度以不超过患者皮肤进针点至手掌面皮肤组织厚度的一半为宜。垂直手背平面直刺或透向后溪、劳宫方向斜刺为针刺的安全方向。应尽量避免在合谷穴进行穴位注射治疗。