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1.
《Clinical neurophysiology》2021,132(9):2003-2011
ObjectiveA large N20 and P25 of the median nerve somatosensory evoked potential (SEP) predicts short survival in amyotrophic lateral sclerosis (ALS). We investigated whether high frequency oscillations (HFOs) over N20 are enlarged and associated with survival in ALS.MethodsA total of 145 patients with ALS and 57 healthy subjects were studied. We recorded the median nerve SEP and measured the onset-to-peak amplitude of N20 (N20o-p), and peak-to-peak amplitude between N20 and P25 (N20p-P25p). We obtained early and late HFO potentials by filtering SEP between 500 and 1 kHz, and measured the peak-to-peak amplitude. We followed up patients until endpoints (death or tracheostomy) and analyzed the relationship between SEP or HFO amplitudes and survival using a Cox analysis.ResultsPatients showed larger N20o-p, N20p-P25p, and early and late HFO amplitudes than the control values. N20p-P25p was associated with survival periods (p = 0.0004), while early and late HFO amplitudes showed no significant association with survival (p = 0.4307, and p = 0.6858, respectively).ConclusionsThe HFO amplitude in ALS is increased, but does not predict survival.SignificanceThe enlarged HFOs in ALS might be a compensatory phenomenon to the hyperexcitability of the sensory cortex pyramidal neurons. 相似文献
2.
《Clinical neurophysiology》2019,130(1):128-137
ObjectiveHigh frequency oscillations (HFO) between 80–500 Hz are markers of epileptic areas in intracranial and maybe also scalp EEG. We investigate simultaneous recordings of scalp and intracranial EEG and hypothesize that scalp HFOs provide important additional clinical information in the presurgical setting.MethodsSpikes and HFOs were visually identified in all intracranial scalp EEG channels. Analysis of correlation of event location between intracranial and scalp EEG as well as relationship between events and the SOZ and zone of surgical removal was performed.Results24 patients could be included, 23 showed spikes and 19 HFOs on scalp recordings. In 15/19 patients highest scalp HFO rate was located over the implantation side, with 13 patients having the highest scalp and intracranial HFO rate over the same region. 17 patients underwent surgery, 7 became seizure free. Patients with poor post-operative outcome showed significantly more regions with HFO than those with seizure free outcome.ConclusionsScalp HFOs are mostly located over the SOZ. Widespread scalp HFOs are indicative of a larger epileptic network and associated with poor postsurgical outcome.SignificanceAnalysis of scalp HFO add clinically important information about the extent of epileptic areas during presurgical simultaneous scalp and intracranial EEG recordings. 相似文献
3.
《Archivos de bronconeumología》2020,56(1):9-17
IntroductionSmall airway dysfunction (SAD) caused by smoking contributes to the early onset of airflow limitation (AFL), although its impact on patients’ perception of health is largely unknown. We aimed to evaluate the frequency of SAD in active smokers without AFL, and to compare health-related quality of life (HRQoL) of non-smokers, smokers without SAD, smokers with SAD, and smokers with AFL.MethodsA total of 53 active smokers without AFL, 20 smokers with AFL, and 20 non-smokers completed the SF-36 and EuroQoL questionnaires and performed impulse oscillometry and spirometry. Pulmonary parenchymal attenuation was determined in inspiration and expiration. SAD was determined to exist when resistance at 5 Hz (R5), the difference between R5 and R20, and reactance area (AX) exceeded the upper limit of normal.ResultsIn total, 35.8% of smokers without AFL had SAD. No differences were detected in spirometric parameters or pulmonary attenuation between smokers with or without AFL and non-smokers. However, smokers with SAD had worse scores on HRQoL questionnaires than smokers without SAD or non-smokers, and scores compared to smokers with AFL were intermediate. R5 and X5 were identified as independent determinants of HRQoL in smokers without AFL.ConclusionsSAD is common in smokers without AFL, affecting one third of this population, and independently affecting their perception of health. 相似文献
4.
目的 探讨缝隙连接阻断剂奎宁(quinine,QUIN)、甘珀酸(carbenoxolone,CBX)对癫痫大鼠海马涟波(ripple)振荡能量变化的影响。 方法 24只大鼠随机分为模型组、丙戊酸(valproate sodium,VPA)组、QUIN组和CBX组(n =6)。建立氯化锂-匹罗卡品(pilocarpine,PILO)癫痫持续状态(status epilepticus,SE)大鼠模型,VPA组、QUIN组和CBX组在注射PILO前3 d,分别给予VPA(抗癫痫一线药物)200 mg/kg灌胃、QUIN 50 mg/kg腹腔注射、CBX 50 mg/kg腹腔注射。脑电图分析各组大鼠造模前后及推注水合氯醛(止痫)前后海马ripple振荡能量改变。 结果 造模前,正常大鼠海马CA1、CA3、齿状回区均可见ripple振荡表达。与建模前1 d比较,注射PILO后10 min,各组ripple平均能量表达逐渐增强,模型组、VPA组和CBX组在止痫前达到最高峰,QUIN组在PILO注射后60 min达到最高峰(P <0.05)。止痫后,3个干预组ripple平均能量恢复至正常水平;模型组在止痫后1 h ripple平均能量恢复至正常水平;且各组均持续正常水平至SE后3 d。ripple最大能量的变化趋势与平均能量类似。 结论 ripple振荡能量改变可以作为癫痫发作早期预警的定量指标;发作间期ripple振荡能量对癫痫的发作并无提示作用;缝隙连接阻断剂可下调癫痫发作期ripple振荡能量。 相似文献
5.
《Brain stimulation》2021,14(1):55-65
BackgroundTemporal interference (TI) stimulation of the brain generates amplitude-modulated electric fields oscillating in the kHz range with the goal of non-invasive targeted deep brain stimulation. Yet, the current intensities required in human (sensitivity) to modulate deep brain activity and if superficial brain region are spared (selectivity) at these intensities remains unclear.ObjectiveWe developed an experimentally constrained theory for TI sensitivity to kHz electric field given the attenuation by membrane low-pass filtering property, and for TI selectivity to deep structures given the distribution of modulated and unmodulated electric fields in brain.MethodsThe electric field threshold to modulate carbachol-induced gamma oscillations in rat hippocampal slices was determined for unmodulated 0.05–2 kHz sine waveforms, and 5 Hz amplitude-modulated waveforms with 0.1–2 kHz carrier frequencies. The neuronal effects are replicated with a computational network model to explore the underlying mechanisms, and then coupled to a validated current-flow model of the human head.ResultsAmplitude-modulated electric fields are stronger in deep brain regions, while unmodulated electric fields are maximal at the cortical regions. Both experiment and model confirmed the hypothesis that spatial selectivity of temporal interference stimulation depends on the phasic modulation of neural oscillations only in deep brain regions. Adaptation mechanism (e.g. GABAb) enhanced sensitivity to amplitude modulated waveform in contrast to unmodulated kHz and produced selectivity in modulating gamma oscillation (i.e. Higher gamma modulation in amplitude modulated vs unmodulated kHz stimulation). Selection of carrier frequency strongly affected sensitivity to amplitude modulation stimulation. Amplitude modulated stimulation with 100 Hz carrier frequency required ∼5 V/m (corresponding to ∼13 mA at the scalp surface), whereas, 1 kHz carrier frequency ∼60 V/m (∼160 mA) and 2 kHz carrier frequency ∼80 V/m (∼220 mA) to significantly modulate gamma oscillation. Sensitivity is increased (scalp current required decreased) for theoretical neuronal membranes with faster time constants.ConclusionThe TI sensitivity (current required at the scalp) depends on the neuronal membrane time-constant (e.g. axons) approaching the kHz carrier frequency. TI selectivity is governed by network adaption (e.g. GABAb) that is faster than the amplitude-modulation frequency. Thus, we show neuronal and network oscillations time-constants determine the scalp current required and the selectivity achievable with TI in humans. 相似文献
6.
High frequency oscillatory ventilation (HFOV) is becoming an increasingly popular intervention in the neonatal intensive care unit. This article will attempt to explain the principles of HFOV. It is inherently more difficult to become skilled in this technique than in other forms of mechanical ventilation, so caution is warranted. 相似文献
7.
Md. Mominul Islam Madhu Sudan Saha Takeyoshi Okajima Takeo Ohsaka 《Journal of electroanalytical chemistry (Lausanne, Switzerland)》2005,577(1):145-154
A study on the current oscillation based on the electrogenerated superoxide ion at a hanging mercury drop electrode (HMDE) in dimethylsulfoxide solution containing tetra-n-alkylammonium perchlorate as the electrolyte was carried out. Cyclic voltammetric, potential step chronoamperometric, normal and reverse pulse voltammetric techniques were employed in this study. A bare glassy carbon electrode, a liquid hemispherical mercury (Hg) drop-coated gold (Au) electrode and a Hg film-coated Au electrode were also used as working electrodes to understand the mechanism of the current oscillation. The experimental conditions were optimized for a simple, regular and reproducible current oscillation. The specific adsorption phenomenon of iodide ion and the adsorption of the alkyl chain of the supporting electrolyte on the HMDE surface were also considered to clarify the experimental factors governing the current oscillation phenomenon. It has been concluded that the oscillation is mainly due to the promoted oxidation (dissolution) of the HMDE itself by the adsorption of , resulting in the formation–destruction of a passive film such as on the electrode surface. A probable mechanism for the observed current oscillation is discussed. 相似文献
8.
9.
本研究通过对属地为河北省医学期刊生存现状进行分析,从期刊资源优化重组,优化编辑人员知识结构,组稿,拓展与稳定广告客户等方面进行研究,以适应市场经济的需要。 相似文献
10.
Rafael F. Escamilla Kyle Yamashiro Russell Dunning Tony Mikla Matthew Grover Mike Kenniston Jesse Loera Travis Tanasse James R. Andrews 《International Journal of Sports Physical Therapy》2016,11(2):175-189