Generator localization by current source density (CSD): Implications of volume conduction and field closure at intracranial and scalp resolutions

The topographic ambiguity and reference-dependency that has plagued EEG/ERP research throughout its history are largely attributable to volume conduction, which may be concisely described by a vector form of Ohm’s Law. This biophysical relationship is common to popular algorithms that infer neuronal generators via inverse solutions. It may be further simplified as Poisson’s source equation, which identifies underlying current generators from estimates of the second spatial derivative of the field potential (Laplacian transformation). Intracranial current source density (CSD) studies have dissected the “cortical dipole” into intracortical sources and sinks, corresponding to physiologically-meaningful patterns of neuronal activity at a sublaminar resolution, much of which is locally cancelled (i.e., closed field). By virtue of the macroscopic scale of the scalp-recorded EEG, a surface Laplacian reflects the radial projections of these underlying currents, representing a unique, unambiguous measure of neuronal activity at scalp. Although the surface Laplacian requires minimal assumptions compared to complex, model-sensitive inverses, the resulting waveform topographies faithfully summarize and simplify essential constraints that must be placed on putative generators of a scalp potential topography, even if they arise from deep or partially-closed fields. CSD methods thereby provide a global empirical and biophysical context for generator localization, spanning scales from intracortical to scalp recordings.     

经封闭式负压引流后应用游离股前外侧皮瓣移植修复足部皮肤缺损的临床疗效

目的探讨经封闭式负压引流后应用游离股前外侧皮瓣移植修复足部皮肤缺损的临床疗效。方法选取2017年1月至2019年1月我院收治的76例足部皮肤缺损患者,随机分为两组,对照组进行经封闭式负压引流治疗,研究组在对照组基础上进行游离股前外侧皮瓣移植修复。比较两组治疗总有效率、生活质量评分、感觉功能恢复状况、植皮成功率。结果与对照组比较,研究组治疗总有效率更高(P0.05);与对照组比较,研究组生活质量评分更高(P0.05);与对照组比较,研究组S3、S1区感觉功能恢复率更高(P0.05),但其余区感觉功能恢复没有明显差异;与对照组比较,研究组植皮成功率更高(P0.05)。结论对足部皮肤缺损患者,应用经封闭式负压引流治疗基础上联合游离股前外侧皮瓣移植修复治疗,效果理想,可提高皮瓣移植成功率,改善生活质量,恢复部分感觉功能。因此,该治疗方法值得广泛应用。     

Huge Amoebic Liver Abscess Presented with Massive Right Empyema: A Case Report

Amoebic liver abscess is a complication of amoebiasis that needs early diagnosis and proper treatment before further complications occur. We report a-35 year old female presented by fever and dyspnea due to huge liver abscess complicated by massive right side empyema. The patient was effectively treated by percutaneous drainage for both the right lobe abscess and empyema together with pharmacologic agents.     

脑出血患者微创引流术后颅内感染的临床分析

目的探讨不同抗菌药物给药途径治疗脑出血患者微创钻颅置管外引流术后颅内感染的临床疗效。方法选择2009年1月-2013年6月72例脑出血行微创钻颅置管外引流术后颅内感染患者为研究对象,将36例行全身给药+腰穿后鞘内注射为A组,25例行全身给药+腰大池引流+鞘内注射为B组,11例行全身给药+脑脊液生理盐水置换为C组,比较3组患者治疗前后脑脊液常规指标差异,治疗期间不同时点脑脊液中的药物浓度以及患者的临床效果。结果 3组患者治疗后颅内压、脑脊液各项指标平均值恢复正常,颅内压值从高到低依次为C、A、B组,差异有统计学意义(F=12.341,P<0.05),C组氯化钠含量较A、B两组低,差异有统计学意义(F=4.621,P<0.05);B组患者治疗后不同时点脑脊液中药物浓度均为最高,C组明显低于A、B两组,差异有统计学意义(P<0.05);3组患者各项指标恢复时间中B组时间最短,C组最长,差异有统计学意义(P<0.05);3组均无明显不良反应发生。结论鞘内抗菌药物注射结合全身抗感染治疗能有效治疗颅内感染,其中腰大池置管引流比多次腰穿更能保证脑脊液中药物浓度,缩短治疗时间。     

风险管理在动脉瘤术后持续腰大池引流中的应用

目的探讨风险管理在动脉瘤术后持续腰大池引流中的临床效果。方法将30例动脉瘤术后持续腰大池引流患者分为对照组14例及观察组16例,比较两组腰大池引流管在脱落、堵塞及过度引流置管护理中并发症的发生率。结果观察组引流管并发症的发生率明显低于对照组,两组间比较差异均有统计学意义(P0.05)。结论对动脉瘤术后持续腰大池引流的患者进行风险管理能降低并发症的发生率,同时提高护士的风险意识,降低护理风险。     

Quantitative EEG Findings Among Men Convicted of Murder

Abstract

Quantitative EEG data were collected from 20 men convicted of murder and sentenced to death. Measures of coherence, phase, amplitude asymmetry, and relative power from 19 scalp electrode sites during an eyes closed, resting condition were compared to a normative database. Measures significantly different from normal were tallied to determine electrode site locations with greatest concentrations of abnormalities. There were more right than left hemisphere abnormalities of coherence, phase, and amplitude asymmetry, and more anterior than posterior abnormalities of phase, amplitude asymmetry, and relative power. Bilateral frontal, right temporal, and parietal sites had the greatest concentrations of multiple abnormalities. Increased coherence and longer neural conduction times characterized the majority of coherence and phase abnormalities. The concentrations of frontal and right hemisphere abnormalities are discussed as relating to impairment, in executive functions, modulation of affect, and perception of affect in others. Such impairments perhaps in conjunction with adverse environmental events, are suggested as placing one at risk for violent behaviors. Relevance of these findings for future research, forensic neuropsychological assessments, and neurofeedback treatment is mentioned.