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121.
局限性癫痫脑电时间序列的分形维数计算比较   总被引:1,自引:0,他引:1  
为探索应用非线性动力学理论诊断癫痫病的新方法,对局限性癫痫病患者脑电时间序列进行了相关维数(Dc)和波形维数(Dw)的计算比较。观察到,痫性导联脑电的分形维数多低于对侧导联的值;相关维数Dc的相对变化量较波形维数Dw大;而波形维数Dw对痫性棘波敏感;结果提示,脑电时间序列的分形维数有可能成为诊断癫痫的特征参数,值得进一步深入研究。  相似文献   
122.
一种EEG信号盲分离和分类的神经网络方法   总被引:2,自引:1,他引:2  
提出一种采用多神经网络处理脑电(EEG)信号的方法。首先,对混有噪声的脑电信号给出一种盲分离的自适应神经算法。通过寻求采样时间序列线性组合的kurtosis系数的局部极值,得出该算法的模型和步骤。在盲分离的基础上,对分离出的估计信号进一步利用Kohonen网络进行分类。将该算法用于300个EEG样本处理,并给出处理结果。  相似文献   
123.
《ITBM》2008,29(1):44-52
Electroencephalogram (EEG) analysis remains problematic due to limited understanding of the signal origin, which leads to the difficulty of designing evaluation methods. In spite of these shortcomings, the EEG is a valuable tool in the evaluation of some neurological disorders as well as in the evaluation of overall cerebral activity. In most studies, which use quantitative EEG analysis, the properties of measured EEG are computed by applying power spectral density (PSD) estimation for selected representative EEG samples. The sample for which the PSD is calculated is assumed to be stationary. This work deals with a comparative study of the PSD obtained from normal, epileptic and alcoholic EEG signals. The power density spectra were calculated using fast Fourier transform (FFT) by Welch's method, auto regressive (AR) method by Yule–Walker and Burg's method. The results are tabulated for these different classes of EEG signals.  相似文献   
124.
The present study sought to objectively describe the spontaneous sleep/wakefulness pattern of shift workers during a 24-hour period. Portable Medilog tape-recorders were used for ambulatory EEG monitoring of 25 male papermill workers (25-55 years) during days with night and afternoon work. The results showed that sleep after night work was two hours shorter than after afternoon work. The sleep reduction affected mainly Stage 2 and REM sleep while slow wave sleep was unchanged. In connection with night work 28% of the workers took a nap in the afternoon. These naps contained a large proportion of slow wave sleep and were, apparently, caused by the sleep deficit after the short main sleep period. The EEG recordings also revealed that 20% of the participants had sleep episodes during night work. These naps were as long as the afternoon naps, were experienced as "dozing offs" rather than naps, occurred at the time of the trough of the circadian wakefulness rhythm, and were concomitant with extreme subjective sleepiness and low rated work load. It was concluded that not only the sleep of shift workers was disturbed, but also the wakefulness--to the extent that sleepiness during night work sometimes reached a level where reasonable wakefulness could not be maintained. The latter observation is probably of special importance in work situations demanding a great responsibility for human lives or for great economic values.  相似文献   
125.
Cortical and hippocampal EEG were correlated with behavior in rats before and after bilateral hypothalamic (LH) damage. In Stage 1 of recovery (aphagia and adipsia), the neocortex showed continuous large amplitude slow activity. It did not desynchronize during spontaneous acts such as grooming as well as during tail pinch-induced struggling or orienting, even though a slow form of hippocampal theta accompanied these acts. However, during Stage 2 (anorexia), the neocortical EEG did desynchronize when such theta appeared. Therefore, as behavioral recovery progresses after LH damage, there appears to be a concomitant recovery of cortical participation in such behavior. Early in recovery, LH rats, unlike normals, showed slow (3–4.5 Hz) atropine-sensitive hippocampal theta during automatisms such as grooming as well as during immobility. Thus, LH damage, while temporarily abolishing fast. noncholinergic theta, appears to release slow cholinergic theta. Later in recovery, faster atropine-resistant (noncholinergic) theta becomes functional again.  相似文献   
126.
This paper presents the relations between the slow (< 1 Hz) oscillation (characterizing the activity of corticothalamic networks during quiescent sleep in cats and humans), sleep K-complexes, and some paroxysmal developments of sleep patterns. At the cellular level, the slow oscillation is built up by rhythmic membrane depolarizations and hyperpolarizations of cortical neurons. The EEG expression of this activity is marked by periodic K-complexes which reflect neuronal excitation. The slow oscillation triggers, groups and synchronizes other sleep rhythms, such as thalamically generated spindles as well as thalamically and cortically generated delta oscillations. We discuss the distinctness of the slow (< 1 Hz) and delta (1–4 Hz) oscillations. We also show that the slow cortical oscillation underlies the onset of spike-wave seizures during sleep by transforming the periodic K-complexes into recurrent paroxysmal spike-wave complexes.  相似文献   
127.
颞叶癫痫的临床特点与脑电图分析   总被引:1,自引:0,他引:1  
目的:分析颞叶癫痫患的临床特点及脑电图定位的意义。方法:回顾分析92例颞叶癫痫患的脑电图。结果:左颞有癫痫样波42例,右颞有癫痫样波29例,双颞有癫痫样波21例,临床表现与癫痫样波发放部位有关,癫痫波的传导主要有容积传导和神经传导方式。结论:结合患临床表现与脑电图癫痫样波起始部位分析有助于致痫灶的定位。  相似文献   
128.
共患抽动障碍的ADHD儿童的脑电生物反馈治疗研究   总被引:7,自引:0,他引:7  
目的:探讨脑电生物反馈治疗共患抽动障碍的注意缺陷多动障碍(ADHD)患儿的疗效。方法:对14例符合美国精神障碍诊断与统计手册第4版(DSM-IV)诊断标准,年龄7~14岁的共患抽动障碍的ADHD患儿进行平均为34次的脑电反馈治疗,治疗前后分别采用Conner父母问卷、Achenbach 量表和Rutter问卷评定行为水平,并测试中国韦氏记忆量表、韦氏儿童智力量表(C-WISC)、持续操作性测试(CPT)等项。抽动障碍严重程度采用耶鲁全面抽动严重程度量表(Yale Global Tic Severity Scale,YGTSS)进行评定。结果:治疗后Conner父母问卷多动指数(10.6±5.6)和Rutter问卷总分(11.5±8.6)较治疗前明显下降,分别为15.7±6.0和17.2±10.5,P<0.01。Achenbach 量表多动因子分治疗后较治疗前明显下降,治疗前后分别为13.2±7.4 和7.5±3.7, P<0.05。Conner父母问卷多动分数有所下降,但差异未达显著性(P>0.05)。治疗后,患儿韦氏记忆量表的记忆商(97.8±11.7)及C-WISC中注意/不分心因子分(106.3±10.6)均高于治疗前(分别为91.3±16.3和95.5±13.0),差异具有显著性(分别为P<0 .05,P<0.01)。在CPT测试中,平均反应时下降(治疗前后分别为523.3±86.7和464.3±68.2毫秒,P<0.05),正确率提高(治疗前后分别为90%和95%,P<0.05)。14例患儿运动抽动和发声抽动在  相似文献   
129.
目的:探索EEG和CT在癫痫的诊断、分型和病因方面的意义。方法:对1379例癫痫进行EEG常规描记和脑CT扫描。结果:1379例中原发性癫痫985例(7143%),继发性癫痫394例(2857%)。CT异常率4619%;EEG异常率7426%,痫波检出率2347%。EEG以局灶性或弥漫性慢波增多为主。EEG和CT的符合率8095%。结论:EEG对癫痫的分型和原发性癫痫的检出有重要价值,而CT则是查找继发性癫痫病因的有效方法  相似文献   
130.
动态脑电图对癫痫诊断和鉴别诊断的意义   总被引:1,自引:0,他引:1  
对临床诊断癫痫的53例和可疑癫痫的117例行24h动态脑电图(AEEG)监测。结果AEEG阳性率(32.9%)明显高于常规EEG(20%),AEEG痫样放电率在癫痫组为54.7%(29/53),可疑癫痫组为15.4%(18/117)。后者中有临床发作者63例,检出痫样放电10例,睡眠期出现痫样放电占89.4%(42/47)。本文对痫样放电出现与临床发作间的关系以及癫痫诊断和鉴别诊断进行了讨论。  相似文献   
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