长程视频脑电图在癫癎分型及预测药物治疗疗效中的应用

目的:探讨长程视频脑电图(VEEG)在癫癎分型及预测药物治疗疗效中的应用。方法:选取深圳市人民医院神经内科2016年6月至2018年7月收治的50例癫癎患者为研究对象,患者均接受VEEG监测,分析患者癫癎发作类型、用药情况、VEEG癎样放电情况及其与预后的关系。结果:50例患者中,经VEEG监测,42例显示癎样放电,8例无癎样放电;不同癫癎类型和不同用药情况下VEEG癎样放电情况比较差异无统计学意义(P>0.05);药物治疗后,无癎样放电者总有效率为87.5%(7/8例),明显高于有癎样放电者64.3%(27/42例)(P<0.05);有癎样放电者与无癎样放电者不良反应比较差异无统计学意义(P>0.05)。结论:VEEG监测可为癫癎患者发作分型及药物治疗起指导作用,有癎样放电者药物治疗有效率比无癎样放电者低。     

Transcranial Focused Ultrasound Modulates Intrinsic and Evoked EEG Dynamics

BackgroundThe integration of EEG recordings and transcranial neuromodulation has provided a useful construct for noninvasively investigating the modification of human brain circuit activity. Recent evidence has demonstrated that focused ultrasound can be targeted through the human skull to affect the amplitude of somatosensory evoked potentials and its associated spectral content.Objective/hypothesisThe present study tests whether focused ultrasound transmitted through the human skull and targeted to somatosensory cortex can affect the phase and phase rate of cortical oscillatory dynamics.MethodsA computational model was developed to gain insight regarding the insertion behavior of ultrasound induced pressure waves in the human head. The instantaneous phase and phase rate of EEG recordings before, during, and after transmission of transcranial focused ultrasound (tFUS) to human somatosensory cortex were examined to explore its effects on phase dynamics.ResultsComputational modeling results show the skull effectively reinforces the focusing of tFUS due to curvature of material interfaces. Neurophysiological recordings show that tFUS alters the phase distribution of intrinsic brain activity for beta frequencies, but not gamma. This modulation was accompanied by a change in phase rate of both beta and gamma frequencies. Additionally, tFUS modulated phase distributions in the beta band of early sensory-evoked activity but did not affect late sensory-evoked activity, lending support to the spatial specificity of tFUS for neuromodulation. This spatial specificity was confirmed through an additional experiment where the ultrasound transducer was moved 1 cm laterally from the original cortical target.ConclusionsFocused ultrasonic energy can alter EEG oscillatory dynamics through local mechanical perturbation of discrete cortical circuits.     

失眠症患者的脑电非线性动力学初步研究

目的探讨失眠症患者在不同认知作业状态下脑电非线性动力学的初步特点。方法应用日本光电1518K脑电图和地形图系统,以及关联维数（D2）、点关联维数（PD2）方法对75例失眠症和64名正常成人在安静闭眼、安静睁眼、闭眼心算作业、睁眼记忆和数字划消五种状态下的脑电数据进行了分析。结果 （1）在D2和PD2上,正常和失眠症睁闭眼实验中差异均未达到显著性。（2）在D2上,与正常对照组比较,失眠症在心算和数字划消两个认知心理测试中均见降低。（3）在PD2上,与正常对照组比较,失眠症在心算、汉字记忆和数字划消三个认知心理测试中也见降低（P〈0.05或P〈0.01）。结论非线性动力学分析为临床提供了一种处理分析脑电信号的新思路,有助于进一步了解失眠症认知过程中大脑的工作机制。     

Ictal tachycardia: The head–heart connection

Epileptic seizures can lead to changes in autonomic function affecting the sympathetic, parasympathetic, and enteric nervous systems. Changes in cardiac signals are potential biomarkers that may provide an extra-cerebral indicator of ictal onset in some patients. Heart rate can be measured easily when compared to other biomarkers that are commonly associated with seizures (e.g., long-term EEG), and therefore it has become an interesting parameter to explore for detecting seizures. Understanding the prevalence and magnitude of heart rate changes associated with seizures, as well as the timing of such changes relative to seizure onset, is fundamental to the development and use of cardiac based algorithms for seizure detection. We reviewed 34 articles that reported the prevalence of ictal tachycardia in patients with epilepsy. Scientific literature supports the occurrence of significant increases in heart rate associated with ictal events in a large proportion of patients with epilepsy (82%) using concurrent electroencephalogram (EEG) and electrocardiogram (ECG). The average percentage of seizures associated with significant heart rate changes was similar for generalized (64%) and partial onset seizures (71%). Intra-individual variability was noted in several articles, with the majority of studies reporting significant increase in heart rate during seizures originating from the temporal lobe. Accurate detection of seizures is likely to require an adjustable threshold given the variability in the magnitude of heart rate changes associated with seizures within and across patients.     

Decreased movement-related beta desynchronization and impaired post-movement beta rebound in amyotrophic lateral sclerosis

ObjectiveThis study explored event-related desynchronization (ERD) and synchronization (ERS) in amyotrophic lateral sclerosis (ALS) to quantify cortical sensorimotor processes during volitional movements. We furthermore compared ERD/ERS measures with clinical scores and movement-related cortical potential (MRCP) amplitudes.MethodsElectroencephalograms were recorded while 21 ALS patients and 19 controls performed two self-paced motor tasks: sniffing and right index finger flexion. Based on Wavelet analysis the alpha and beta frequency bands were selected for subsequent evaluation.ResultsPatients generated significantly smaller resting alpha spectral power density (SPD) and smaller beta ERD compared to controls. Additionally patients exhibited merely unilateral post-movement ERS (beta rebound) whereas this phenomenon was bilateral in controls. ERD/ERS amplitudes did not correlate with corresponding MRCPs for either patients or controls.ConclusionsThe smaller resting alpha SPD and beta ERD and asymmetrical appearance of beta ERS in patients compared to controls could be the result of pyramidal cell degeneration and/or corpus callosum involvement in ALS.SignificanceThese results support the notion of reduced movement preparation in ALS involving also areas outside the motor cortex. Furthermore post-movement cortical inhibition seems to be impaired in ALS. ERD/ERS and MRCP are found to be independent measures of cortical motor functions in ALS.     

Age dependent electroencephalographic changes in attention-deficit/hyperactivity disorder (ADHD)

ObjectiveObjective biomarkers for attention-deficit/hyperactivity disorder (ADHD) could improve diagnostics or treatment monitoring of this psychiatric disorder. The resting electroencephalogram (EEG) provides non-invasive spectral markers of brain function and development. Their accuracy as ADHD markers is increasingly questioned but may improve with pattern classification.MethodsThis study provides an integrated analysis of ADHD and developmental effects in children and adults using regression analysis and support vector machine classification of spectral resting (eyes-closed) EEG biomarkers in order to clarify their diagnostic value.ResultsADHD effects on EEG strongly depend on age and frequency. We observed typical non-linear developmental decreases in delta and theta power for both ADHD and control groups. However, for ADHD adults we found a slowing in alpha frequency combined with a higher power in alpha-1 (8–10 Hz) and beta (13–30 Hz). Support vector machine classification of ADHD adults versus controls yielded a notable cross validated sensitivity of 67% and specificity of 83% using power and central frequency from all frequency bands. ADHD children were not classified convincingly with these markers.ConclusionsResting state electrophysiology is altered in ADHD, and these electrophysiological impairments persist into adulthood.SignificanceSpectral biomarkers may have both diagnostic and prognostic value.     

Cognitive and physical training for the elderly: Evaluating outcome efficacy by means of neurophysiological synchronization

Recent neuroscientific research has demonstrated that both healthy and pathological aging induces alterations in the co-operative capacity of neuronal populations in the brain. Both compensatory and neurodegenerative mechanisms contribute to neurophysiological synchronization patterns, which provide a valuable marker for age-related cognitive decline. In this study, we propose that neuroplasticity-based training may facilitate coherent interaction of distant brain regions and consequently enhance cognitive performance in elderly people. If this is true, this would make neurophysiological synchronization a valid outcome measure to assess the efficacy of non-pharmacological interventions to prevent or delay age-related cognitive decline. The present study aims at providing an objective, synchronization-based tool to assess cognitive and/or physical interventions, adopting the notion of Relative Wavelet Entropy. This mathematical model employs a robust and parameter-free synchronization metric. By using data mining techniques, a distance value was computed for all participants so as to quantify the proximity of their individual profile to the mean group synchronization increase. In support of our hypothesis, results showed a significant increase in synchronization, for four electrode pairs, in the intervention group as compared to the active control group. It is concluded that the novel introduction of neurophysiological synchronization features could be used as a valid and reliable outcome measure; while the distance-based analysis could provide a reliable means of evaluating individual benefits.     

Cognitive impairment in obstructive sleep apnea

Obstructive sleep apnea (OSA) is characterised by repetitive cessation or reduction of airflow due to upper airway obstructions. These respiratory events lead to chronic sleep fragmentation and intermittent hypoxemia. Several studies have shown that OSA is associated with daytime sleepiness and cognitive dysfunctions, characterized by impairments of attention, episodic memory, working memory, and executive functions. This paper reviews the cognitive profile of adults with OSA and discusses the relative role of altered sleep and hypoxemia in the aetiology of these cognitive deficits. Markers of cognitive dysfunctions such as those measured with waking electroencephalography and neuroimaging are also presented. The effects of continuous positive airway pressure (CPAP) on cognitive functioning and the possibility of permanent brain damage associated with OSA are also discussed. Finally, this paper reviews the evidence suggesting that OSA is a risk factor for developing mild cognitive impairment and dementia in the aging population and stresses the importance of its early diagnosis and treatment.