12 research outputs found
Age-related network topological difference based on the sleep ECG signal
Age has been shown to be a crucial factor for the EEG and fMRI small-world networks during sleep. However, the characteristics of the age-related network based on sleep ECG signal and how the network changes during different sleep stages are poorly understood. This study focuses on to explore the age-related scale-free and small-world network properties of the ECG signal from male subjects during distinct sleep stages, including the wakeful(W), light sleep (LS), deep sleep (DS) and rapid eye movement (REM) stages. The subjects are divided into two age groups: younger (age<=40, n=11) group and older group (age>40, n=25). For the scale-free network analysis, our results reveal a distinctive pattern of the scale free network topologies between two age groups, including the mean degree ( ), the clustering coefficient ( ), and the path length ( )features, such as the slope distribution of in younger group increased from 1.99 during W to above 2.05 during DS. In addition, the results indicate that the small-world properties can be found across all sleep stages in both age groups. But the small-world index in the LS and REM stages significantly decreased with age (p=0.0006 and p=0.05 respectively). The comparison analysis result indicates that the network topology variations of the sleep ECG signals prone to show age-relevant differences which could be used for sleep stage classification and sleep disorder diagnosis
Abnormal Default Mode Network Homogeneity in Treatment-Naive Patients With First-Episode Depression
Background and Objective: The default mode network (DMN) may be an important component involved in the broad-scale cognitive problems seen in patients with first-episode treatment-naive depression. Nevertheless, information is scarce regarding the changes in network homogeneity (NH) found in the DMN of these patients. Therefore, in this study, we explored the NH of the DMN in patients with first-episode treatment-naive depression.Methods: The study included 66 patients and 74 control participants matched by age, gender, educational level and health status who underwent resting-state functional magnetic resonance imaging (rs-fMRI) and the attentional network test (ANT). To assess data, the study utilizes NH and independent component analysis (ICA). Additionally, Spearman's rank correlation analysis is performed among significantly abnormal NH in depression patients and clinical measurements and executive control reaction time (ECRT).Results: In comparison with the control group, patients with first-episode treatment-naive depression showed lower NH in the bilateral angular gyrus (AG), as well as increased NH in the bilateral precuneus (PCu) and posterior cingulate cortex (PCC). Likewise, patients with first-episode treatment-naive depression had longer ECRT. No significant relation was found between abnormal NH values and the measured clinical variables.Conclusions: Our results suggest patients with first-episode treatment-naive depression have abnormal NH values in the DMN. This highlights the significance of DMN in the pathophysiology of cognitive problems in depression. Our study also found alterations in executive functions in patients with first-episode treatment-naive depression
Disrupted Structural and Functional Networks and Their Correlation with Alertness in Right Temporal Lobe Epilepsy: A Graph Theory Study
Previous studies have shown that temporal lobe epilepsy (TLE) involves abnormal structural or functional connectivity in specific brain areas. However, limited comprehensive studies have been conducted on TLE associated changes in the topological organization of structural and functional networks. Additionally, epilepsy is associated with impairment in alertness, a fundamental component of attention. In this study, structural networks were constructed using diffusion tensor imaging tractography, and functional networks were obtained from resting-state functional MRI temporal series correlations in 20 right temporal lobe epilepsy (rTLE) patients and 19 healthy controls. Global network properties were computed by graph theoretical analysis, and correlations were assessed between global network properties and alertness. The results from these analyses showed that rTLE patients exhibit abnormal small-world attributes in structural and functional networks. Structural networks shifted toward more regular attributes, but functional networks trended toward more random attributes. After controlling for the influence of the disease duration, negative correlations were found between alertness, small-worldness, and the cluster coefficient. However, alertness did not correlate with either the characteristic path length or global efficiency in rTLE patients. Our findings show that disruptions of the topological construction of brain structural and functional networks as well as small-world property bias are associated with deficits in alertness in rTLE patients. These data suggest that reorganization of brain networks develops as a mechanism to compensate for altered structural and functional brain function during disease progression
Carisbamate add-on therapy for drug-resistant focal epilepsy
BACKGROUND: Epilepsy is one of the most common neurological disorders. Many people with epilepsy are drugâresistant and require addâon therapy, meaning that they concomitantly take multiple antiepileptic drugs. Carisbamate is a drug which is taken orally and inhibits voltageâgated sodium channels. Carisbamate may be useful for drugâresistant focal epilepsy. OBJECTIVES: To evaluate the efficacy and tolerability of carisbamate when used as an addâon therapy for drugâresistant focal epilepsy. SEARCH METHODS: We searched the following databases on 8 April 2021: Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid) 1946 to April 07, 2021. CRS Web includes randomised or quasiârandomised controlled trials from PubMed, Embase, ClinicalTrials.gov, WHO ICTRP, the Cochrane Central Register of Controlled Trials (CENTRAL), and the specialised registers of Cochrane review groups including Epilepsy. We also searched ongoing trials registers, checked reference lists, and contacted authors of the included trials. SELECTION CRITERIA: Doubleâblind randomised controlled trials (RCTs) comparing carisbamate versus placebo or another antiepileptic drug, as addâon therapy for drugâresistant focal epilepsy. Trials could have a parallelâgroup or crossâover design. DATA COLLECTION AND ANALYSIS: Two review authors independently selected the trials for inclusion, assessed trial quality, and extracted data. The primary outcome was 50% or greater reduction in seizure frequency (responder rate). The secondary outcomes were: seizure freedom, treatment withdrawal (for any reason and due to adverse events); adverse events, and quality of life. We analysed data using the MantelâHaenszel statistical method and according to the intentionâtoâtreat population. We presented results as risk ratios (RRs) with 95% confidence intervals (CIs). MAIN RESULTS: We included four RCTs involving a total of 2211 participants. All four trials compared carisbamate with placebo for drugâresistant focal epilepsy. Participants in all trials were over 16 years of age and received at least one other antiepileptic drug concomitantly. We detected substantial risk of bias across the included trials. All four trials were at high risk of attrition bias due to the incomplete reporting of attrition and the high treatment withdrawal rates noted, especially with higher doses. All four trials also had unclear risk of detection bias, as they did not specify whether outcome assessors were blinded. Metaâanalysis suggested that carisbamate produced a higher responder rate compared to placebo (RR 1.36, 95% CI 1.14 to 1.62; 4 studies; moderateâcertainty evidence). More participants in the carsibamate group achieved seizure freedom (RR 2.43, 95% CI 0.84 to 7.03; 1 study); withdrew from treatment for any reason (RR 1.32, 95% CI 0.82 to 2.12; 4 studies); and withdrew from treatment due to adverse events (RR 1.80, 95% CI 0.78 to 4.17; 4 studies) than in the placebo group. However, the evidence for the three outcomes was very lowâcertainty. There was no difference between treatment groups for the proportion of participants experiencing at least one adverse event (RR 1.10, 95% CI 0.93 to 1.30; 2 studies; lowâcertainty evidence). More participants in the carisbamate group than in the placebo group developed dizziness (RR 2.06, 95% CI 1.23 to 3.44; 4 studies; very lowâcertainty evidence) and somnolence (RR 1.82, 95% CI 1.28 to 2.58; 4 studies; lowâcertainty evidence), but not fatigue (RR 1.11, 95% CI 0.73 to 1.68; 3 studies); headache (RR 1.13, 95% CI 0.92 to 1.38; 4 studies); or nausea (RR 1.19, 95% CI 0.81 to 1.75; 3 studies). None of the included trials reported quality of life. AUTHORS' CONCLUSIONS: The results suggest that carisbamate may demonstrate efficacy and tolerability as an addâon therapy for drugâresistant focal epilepsy. Importantly, the evidence for all outcomes except responder rate was of low to very low certainty, therefore we are uncertain of the accuracy of the reported effects. The certainty of the evidence is limited by the significant risk of bias associated with the included studies, as well as the statistical heterogeneity detected for some outcomes. Consequently, it is difficult for these findings to inform clinical practice. The studies were all of short duration and only included adult study populations. There is a need for further RCTs with more clear methodology, longâterm followâup, more clinical outcomes, more seizure types, and a broader range of participants
Ultrasensitive All-Carbon Photoelectrochemical Bioprobes for Zeptomole Immunosensing of Tumor Markers by an Inexpensive Visible Laser Light
A novel
enzyme-free and all-carbon photoelectrochemical (PEC) bioprobe,
based on carboxylated multiwalled carbon nanotubeâCongo redâfullerene
nanohybrids (MWNTCOOHâCRâC<sub>60</sub>), for the ultrasensitive
immunosensing of carcinoembryonic antigen (CEA) was reported. The
MWNTCOOHâCRâC<sub>60</sub> nanohybrids, prepared by
mechanically grinding a mixture of MWNTCOOH, C<sub>60</sub>, and CR
at a certain mass ratio, had good water dispersibility and high PEC
conversion efficiency in visible light ranges. Covalent binding of
the detection antibody of CEA on the MWNTCOOHâCRâC<sub>60</sub> nanohybrids produced a sensitive PEC bioprobe for detection
of CEA by sandwich immunosensing. The corresponding immunosensor,
employing an inexpensive and portable green laser light, possessed
a wide calibration range of 1.0 pg/mLâŒ100.0 ng/mL and a low
detection limit of 0.1 pg/mL (calculated 5 zmol for a 10.0 ÎŒL
sample solution) (S/N = 3), which was successfully applied to the
detection of CEA in serum samples from both healthy people and cancer
patients. The present work thus demonstrated the promising application
of fullerene-based nanocomposites in developing highly sensitive,
environmentally friendly, and cost-effective PEC biosensors