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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
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3.
《Revista brasileira de otorrinolaringologia (English ed.)》2015,81(3):264-269
IntroductionThere is still no consensus in the literature as to the best acoustic stimulus for capturing vestibular evoked myogenic potential (VEMP). Low-frequency tone bursts are generally more effective than high-frequency, but recent studies still use clicks. Reproducibility is an important analytical parameter to observe the reliability of responses.ObjectiveTo determine the reproducibility of p13 and n23 latency and amplitude of the VEMP for stimuli with different tone-burst frequencies, and to define the best test frequency.MethodsCross-sectional cohort study. VEMP was captured in 156 ears, on the sternocleidomastoid muscle, using 100 tone-burst stimuli at frequencies of 250, 500, 1000, and 2000 Hz, and sound intensity of 95 dB nHL. Responses were replicated, that is, recorded three times on each side.ResultsNo significant difference was observed for p13 and n23 latencies of the VEMP, captured at three moments with tone-burst stimuli at 250, 500, and 1000 Hz. Only the frequency of 2000 Hz showed a difference between captures of this potential (p < 0.001). p13 and n23 amplitude analysis was also similar in the test–retest for all frequencies analyzed.Conclusionp13 and n23 latencies and amplitudes of VEMP for tone-burst stimuli at frequencies of 250, 500, and 1000 Hz are reproducible. 相似文献
4.
《Clinical neurophysiology》2020,131(1):259-264
ObjectivesFasciculation potentials (FP) are an important consideration in the electrophysiological diagnosis of ALS. Muscle ultrasonography (MUS) has a higher sensitivity in detecting fasciculations than electromyography (EMG), while in some cases, it is unable to detect EMG-detected fasciculations. We aimed to investigate the differences of FP between the muscles with and without MUS-detected fasciculations (MUS-fas).MethodsThirty-one consecutive patients with sporadic ALS were prospectively recruited and in those, both needle EMG and MUS were performed. Analyses of the amplitude, duration, and number of phases of EMG-detected FPs were performed for seven muscles per patient, and results were compared between the muscles with and without MUS-fas in the total cohort.ResultsThe mean amplitude and phase number of FP were significantly lower in patients with EMG-detected FP alone (0.39 ± 0.25 mV and 3.21 ± 0.88, respectively) than in those with both FP and MUS-fas (1.22 ± 0.92 mV and 3.74 ± 1.39, respectively; p < 0.0001 and p = 0.017, Welch’s t-test).ConclusionSmall FP may be undetectable with MUS. MUS cannot replace EMG in the diagnostic approach for ALS.SignificanceClinicians should use a combination of EMG and MUS for the detection and quantitative analysis of fasciculation in ALS. 相似文献
5.
Qian Li Tian-Le Ma You-Qi Qiu Wen-Qiang Cui Teng Chen Wen-Wen Zhang Jing Wang Qi-Liang Mao-Ying Wen-Li Mi Yan-Qing Wang Yu-Xia Chu 《神经科学通报》2020,36(12):1484
Trigeminal neuralgia is a debilitating condition, and the pain easily spreads to other parts of the face. Here, we established a mouse model of partial transection of the infraorbital nerve (pT-ION) and found that the Connexin 36 (Cx36) inhibitor mefloquine caused greater alleviation of pT-ION-induced cold allodynia compared to the reduction of mechanical allodynia. Mefloquine reversed the pT-ION-induced upregulation of Cx36, glutamate receptor ionotropic kainate 2 (GluK2), transient receptor potential ankyrin 1 (TRPA1), and phosphorylated extracellular signal regulated kinase (p-ERK) in the trigeminal ganglion. Cold allodynia but not mechanical allodynia induced by pT-ION or by virus-mediated overexpression of Cx36 in the trigeminal ganglion was reversed by the GluK2 antagonist NS102, and knocking down Cx36 expression in Nav1.8-expressing nociceptors by injecting virus into the orofacial skin area of Nav1.8-Cre mice attenuated cold allodynia but not mechanical allodynia. In conclusion, we show that Cx36 contributes greatly to the development of orofacial pain hypersensitivity through GluK2, TRPA1, and p-ERK signaling.Electronic supplementary materialThe online version of this article (10.1007/s12264-020-00594-4) contains supplementary material, which is available to authorized users. 相似文献
6.
《Brain stimulation》2022,15(2):337-351
BackgroundAbnormalities in frontoparietal network (FPN) were observed in many neuropsychiatric diseases including substance use disorders. A growing number of studies are using dual-site-tACS with frontoparietal synchronization to engage this network. However, a computational pathway to inform and optimize parameter space for frontoparietal synchronization is still lacking. In this case study, in a group of participants with methamphetamine use disorders, we proposed a computational pathway to extract optimal electrode montage while accounting for stimulation intensity using structural and functional MRI.MethodsSixty methamphetamine users completed an fMRI drug cue-reactivity task. Four main steps were taken to define electrode montage and adjust stimulation intensity using 4x1 high-definition (HD) electrodes for a dual-site-tACS; (1) Frontal seed was defined based on the maximum electric fields (EF) predicted by simulation of HD montage over DLPFC (F3/F4 in EEG 10–10), (2) frontal seed-to-whole brain context-dependent correlation was calculated to determine connected regions to frontal seeds, (3) center of connected cluster in parietal cortex was selected as a location for placing the second set of HD electrodes to shape the informed montage, (4) individualized head models were used to determine optimal stimulation intensity considering underlying brain structure. The informed montage was compared to montages with large electrodes and classic frontoparietal HD montages (F3-P3/F4-P4) in terms of tACS-induced EF and ROI-to-ROI task-based/resting-state connectivity.ResultsCompared to the large electrodes, HD frontoparietal montages allow for a finer control of the spatial peak fields in the main nodes of the FPN at the cost of lower maximum EF (large-pad/HD: max EF[V/m] = 0.37/0.11, number of cortical sub-regions that EF exceeds 50% of the max = 77/13). For defining stimulation targets based on EF patterns, using group-level head models compared to a single standard head model results in comparable but significantly different seed locations (6.43 mm Euclidean distance between the locations of the frontal maximum EF in standard-space). As expected, significant task-based/resting-state connections were only found between frontal-parietal locations in the informed montage. Cue-induced craving score was correlated with frontoparietal connectivity only in the informed montage (r = ?0.24). Stimulation intensity in the informed montage, and not in the classic HD montage, needs 40% reduction in the parietal site to reduce the disparity in EF between stimulation sites.ConclusionThis study provides some empirical insights to montage and dose selection in dual-site-tACS using individual brain structures and functions and proposes a computational pathway to use head models and functional MRI to define (1) optimum electrode montage for targeting FPN in a context of interest (drug-cue-reactivity) and (2) proper transcranial stimulation intensity. 相似文献
7.
《Clinical neurophysiology》2021,132(12):3104-3115
ObjectiveWe aimed to establish an objective neurophysiological test protocol that can be used to assess the somatosensory nervous system.MethodsIn order to assess most fiber subtypes of the somatosensory nervous system, repetitive stimuli of seven different modalities (touch, vibration, pinprick, cold, contact heat, laser, and warmth) were synchronized with the electroencephalogram (EEG) and applied on the cheek and dorsum of the hand and dorsum of the foot in 21 healthy subjects and three polyneuropathy (PNP) patients. Latencies and amplitudes of the modalities were assessed and compared. Patients received quantitative sensory testing (QST) as reference.ResultsWe found reproducible evoked potentials recordings for touch, vibration, pinprick, contact-heat, and laser stimuli. The recording of warm-evoked potentials was challenging in young healthy subjects and not applicable in patients. Latencies were shortest within Aβ-fiber-mediated signals and longest within C-fibers. The test protocol detected function loss within the Aβ-fiber and Aδ-fiber-range in PNP patients. This function loss corresponded with QST findings.ConclusionIn this pilot study, we developed a neurophysiological test protocol that can specifically assess most of the somatosensory modalities. Despite technical challenges, initial patient data appear promising regarding a possible future clinical application.SignificanceEstablished and custom-made stimulators were combined to assess different fiber subtypes of the somatosensory nervous system using modality-specific evoked potentials. 相似文献
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9.
目的 观察单次9 h高压氧(hyp erbaric oxygen,HBO)治疗对局灶性脑梗死大鼠凋亡诱导因子
(apoptosis-inducing factor,AIF)、线粒体膜电位(mitochondrial membrane potential,MMPo)的影响,探讨
HBO治疗的神经保护作用。
方法 108只SD大鼠制作永久性大脑中动脉闭塞模型,随机分为对照组和HBO组,每组各54只。造
模成功3 h后,HBO组实行HBO干预,压力0.2 MPa持续9 h,对照组呼吸常压空气。采用Garcia评分评估
大鼠神经功能,比较两组造模后13 h、24 h和72 h神经功能改善情况,并在各时间点检测大鼠缺血半
暗带脑组织凋亡细胞数、线粒体和细胞核AIF表达及MMPo水平。
结果 ①神经功能评分:HBO组13 h(P <0.001)、24 h(P =0.04)神经功能评分改善比对照组更明显。
②凋亡细胞数:HBO组13 h、24 h凋亡细胞数较对照组更少(均P <0.001)。③AIF在线粒体和细胞核的
表达:13 h、24 h、72 h各时间点HBO组AI F在线粒体的表达均较对照组多(均P <0.001);各时间点HBO
组AIF在细胞核的表达均较对照组少(均P <0.001)。④MMPo:各时间点HBO组MMPo均高于对照组(均
P <0.001)。
结论 HBO治疗可改善大鼠神经功能,稳定MMPo,抑制AIF由线粒体向细胞核转移可能是其神经保
护作用的机制之一。 相似文献
10.
Jae Eun Choi Tyler Werbel Zhenping Wang Chia Chi Wu Tony L. Yaksh Anna Di Nardo 《Journal of dermatological science》2019,93(1):58-64