scholarly journals Abnormalities in cortical pattern of coherence in interictal migraine detected using ultra high-density EEG

2020 ◽  
Author(s):  
Alireza Chamanzar ◽  
Sarah M Haigh ◽  
Pulkit Grover ◽  
Marlene Behrmann
Keyword(s):  
Repeated Measures ◽  
Visual Stimulation ◽  
Temporal Frequency ◽  
High Density ◽  
Auditory Stimuli ◽  
Long Distance ◽  
Significant Group ◽  
Frequency Bands ◽  
Color Detection ◽  
The Right

Individuals with migraine generally experience photophobia and/or phonophobia during and between migraine attacks. Many different mechanisms have been postulated to explain these migraine phenomena including abnormal patterns of connectivity across the cortex. The results, however, remain contradictory and there is no clear consensus on the nature of the cortical abnormalities in migraine. Here, we uncover alterations in cortical patterns of coherence (connectivity) in interictal migraineurs during the presentation of visual and auditory stimuli, as well as at rest, to capitalize on the sensory sensitivities that are characteristic of migraine, and to reconcile the conflicting literature on migraine cortical connectivity. We used a high-density electroencephalography (HD-EEG) system, with 128 customized electrode locations, to measure inter- and intra-hemispheric coherence from 17 individuals with migraine (12 female) in the interictal period, and 18 age- and gender-matched healthy control subjects, during visual (vertical grating pattern) and auditory (modulated tone) stimulation which varied in temporal frequency (4 and 6Hz), and during rest. To ensure that participants were attending, participants performed a color detection task at fixation. Analyses of the EEG signal included characterizing the inter- and intra-hemisphere coherence between the scalp EEG channels over 2-second time intervals and over different frequency bands at different spatial distances and spatial clusters, and Pearson's correlation coefficients (PCCs) were estimated at zero-lag. Repeated measures (between-group) analyses-of-variance with post hoc multiple comparison correction were conducted. Relative to controls, migraineurs exhibited significantly (i) faster color detection performance; (ii) lower long-distance spatial coherence of alpha-band activity during both evoked conditions, regardless of the stimulation frequency; (iii) lower coherence between the right frontal cluster and all clusters in the left hemisphere (inter-hemisphere coherence) during 4Hz auditory and visual stimulation; and (iv) lower long-distance coherence (in all frequency bands) between the right occipito-parietal cluster and all other clusters during the (4Hz and 6Hz) visual stimuli. No significant group differences were observed in the resting state data. The abnormal patterns of EEG coherence in interictal migraineurs during visual and auditory stimuli may be associated with cortical hyper-excitability in migraineurs.

scholarly journals Acetazolamide-Induced Vasodilation Does Not Inhibit the Visually Evoked Flow Response

2009 ◽  
Vol 30 (3) ◽  
pp. 516-521 ◽  
Author(s):  
Yaniv Yonai ◽  
Neta Boms ◽  
Sandor Molnar ◽  
Bernhard Rosengarten ◽  
Natan M Bornstein ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Repeated Measures ◽  
Pulsatility Index ◽  
Visual Stimulation ◽  
Neurovascular Coupling ◽  
Maximal Effect ◽  
Significant Group ◽  
Before And After ◽  
Cerebral Vasodilation ◽  
Relative Flow

Different methods are used to assess the vasodilator ability of cerebral blood vessels; however, the exact mechanism of cerebral vasodilation, induced by different stimuli, is not entirely known. Our aim was to investigate whether the potent vasodilator agent, acetazolamide (AZ), inhibits the neurovascular coupling, which also requires vasodilation. Therefore, visually evoked flow parameters were examined by transcranial Doppler in ten healthy subjects before and after AZ administration. Pulsatility index and peak systolic flow velocity changes, evoked by visual stimulus, were recorded in the posterior cerebral arteries before and after intravenous administration of 15 mg/kg AZ. Repeated-measures ANOVA did not show significant group main effect between the visually evoked relative flow velocity time courses before and after AZ provocation ( P=0.43). Visual stimulation induced significant increase of relative flow velocity and decrease of pulsatility index not only before but also at the maximal effect of AZ. These results suggest that maximal cerebral vasodilation cannot be determined by the clinically accepted dose of AZ (15 mg/kg) and prove that neurovascular coupling remains preserved despite AZ-induced vasodilation. Our observation indicates independent regulation of vasodilation during neurovascular coupling, allowing the adaptation of cerebral blood flow according to neuronal activity even if other processes require significant vasodilation.

Predialytic versus Intradialytic Nutrition: A Study to Assess Effects on Intradialytic Blood Pressure, Dialysis Adequacy, and Urea Removal

2021 ◽  
pp. 1-6
Author(s):  
Namrata S. Rao ◽  
Abhilash Chandra ◽  
Sai Saran ◽  
Manish Raj Kulshreshta ◽  
Prabhakar Mishra ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Dialysis Adequacy ◽  
Fasting Period ◽  
Significant Group ◽  
Protein Requirements ◽  
Dialysis Vintage ◽  
Oral Nutritional Supplements ◽  
Blood Pressures ◽  
Group 2 ◽  
Group 1

<b><i>Background:</i></b> Provision of oral protein in hemodialysis (HD) is desirable due to improved compliance to protein requirements and better nutritional status, but the risks of hypotension and underdialysis need to be considered. This study compared 2 different timings for administering oral nutritional supplements (ONS), predialysis and mid-dialysis, with respect to hemodynamics, dialysis adequacy, urea removal, and tolerability. <b><i>Methods:</i></b> This single-center, prospective crossover study analyzed 72 stable patients with ESRD on twice a week maintenance HD with a mean age of 38.7 (±11.2) years and a dialysis vintage of 28.2 (±13.1) months. In the first week, all the patients received ONS (450 kcal energy, 20 g protein) 1 h prior to start of dialysis (group 1) and in the next week, the supplement was administered after 2 h of start of dialysis (group 2), with a predialysis fasting period of at least 3 h in both groups. Blood pressures, serum, and spent dialysate samples were collected and nausea occurrence was noted by severity. <b><i>Results:</i></b> Predialytic intake (group 1) was associated with higher predialysis and 1st hour blood urea, dialysis adequacy, and urea removal than group 2. Both groups achieved mean Kt/V &#x3e; 1.2, and the occurrence of symptomatic hypotensive episodes and nausea was not significantly different between the groups. On repeated measures ANOVA, changes in blood urea over time showed significant group effect. <b><i>Conclusions:</i></b> Predialytic supplementation was associated with better dialysis adequacy and urea removal than intradialytic supplementation. However, both timings were equally tolerated and not associated with underdialysis.

White Matter Alteration Following SWAT Explosive Breaching Training and the Moderating Effect of a Neck Collar Device: A DTI and NODDI Study

2021 ◽  
Author(s):  
Weihong Yuan ◽  
Jonathan Dudley ◽  
Alexis B Slutsky-Ganesh ◽  
James Leach ◽  
Pete Scheifele ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Moderating Effect ◽  
Significant Group ◽  
Blast Exposure ◽  
Diffusion Weighted ◽  
Weighted Data ◽  
The Right ◽  
The Impact

ABSTRACT Introduction Special Weapons and Tactics (SWAT) personnel who practice breaching with blast exposure are at risk for blast-related head trauma. We aimed to investigate the impact of low-level blast exposure on underlying white matter (WM) microstructure based on diffusion tensor imaging (DTI) and neurite orientation and density imaging (NODDI) in SWAT personnel before and after breacher training. Diffusion tensor imaging is an advanced MRI technique sensitive to underlying WM alterations. NODDI is a novel MRI technique emerged recently that acquires diffusion weighted data from multiple shells modeling for different compartments in the microstructural environment in the brain. We also aimed to evaluate the effect of a jugular vein compression collar device in mitigating the alteration of the diffusion properties in the WM as well as its role as a moderator on the association between the diffusion property changes and the blast exposure. Materials and Methods Twenty-one SWAT personnel (10 non-collar and 11 collar) completed the breacher training and underwent MRI at both baseline and after blast exposure. Diffusion weighted data were acquired with two shells (b = 1,000, 2,000 s/mm2) on 3T Phillips scanners. Diffusion tensor imaging metrices, including fractional anisotropy, mean, axial, and radial diffusivity, and NODDI metrics, including neurite density index (NDI), isotropic volume fraction (fiso), and orientation dispersion index, were calculated. Tract-based spatial statistics was used in the voxel-wise statistical analysis. Post hoc analyses were performed for the quantification of the pre- to post-blast exposure diffusion percentage change in the WM regions with significant group difference and for the assessment of the interaction of the relationship between blast exposure and diffusion alteration. Results The non-collar group exhibited significant pre- to post-blast increase in NDI (corrected P &lt; .05) in the WM involving the right internal capsule, the right posterior corona radiation, the right posterior thalamic radiation, and the right sagittal stratum. A subset of these regions showed significantly greater alteration in NDI and fiso in the non-collar group when compared with those in the collar group (corrected P &lt; .05). In addition, collar wearing exhibited a significant moderating effect for the alteration of fiso for its association with average peak pulse pressure. Conclusions Our data provided initial evidence of the impact of blast exposure on WM diffusion alteration based on both DTI and NODDI. The mitigating effect of WM diffusivity changes and the moderating effect of collar wearing suggest that the device may serve as a promising solution to protect WM against blast exposure.

Location, Location, Location: Accelerometer Placement Affects Steps-Based Physical Activity Outcomes During Pregnancy and Postpartum

2021 ◽  
pp. 155982762110304
Author(s):  
Mallory R. Marshall ◽  
Alexander H. K. Montoye ◽  
Michelle R. Conway ◽  
Rebecca A. Schlaff ◽  
Karin A. Pfeiffer ◽  
...  
Keyword(s):  
Physical Activity ◽  
Repeated Measures ◽  
Time Points ◽  
Repeated Measures Analysis ◽  
Pregnancy And Postpartum ◽  
Vigorous Intensity ◽  
The Right ◽  
Physical Changes ◽  
Intensity Classification ◽  
Measurement Validity

As pregnancy progresses, physical changes may affect physical activity (PA) measurement validity. n = 11 pregnant women (30.1 ± 3.8 years) wore ActiGraph GT3X+ accelerometers on the right hip, right ankle, and non-dominant wrist for 3–7 days during the second and third trimesters (21 and 32 weeks, respectively) and 12 weeks postpartum. Data were downloaded into 60-second epochs from which stepping cadence was calculated; repeated-measures analysis of variance was used to determine significant differences among placements. At all time points, the wrist accelerometer measured significantly more daily steps (9930–10 452 steps/d) and faster average stepping cadence (14.5–14.6 steps/min) than either the hip (4972–5944 steps/d, 7.1–8.6 steps/min) or ankle (7161–8205 steps/d, 10.3–11.9 steps/min) placement, while moderate- to vigorous-intensity activity at the wrist (1.2–1.7 min/d) was significantly less than either hip (3.0–5.9 min/d) or ankle (6.1–7.3 min/d). Steps, cadence, and counts were significantly lower for the hip than the ankle at all time points. Kappa calculated for agreement in intensity classification between the various pairwise comparisons ranged from .06 to .41, with Kappa for hip–ankle agreement (.34–.41) significantly higher than for wrist–ankle (.09–.11) or wrist–hip (.06–.16). These data indicate that wrist accelerometer placement during pregnancy likely results in over counting of PA parameters and should be used with caution.

P957Characteristics of atrial tachycardia after mitral surgey via biatrial trans-septal approach using high density mapping system

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
C Cataldi ◽  
M Andronache ◽  
R Eschalier ◽  
F Jean ◽  
R Bosle ◽  
...  
Keyword(s):  
Atrial Tachycardia ◽  
Sinus Node ◽  
Pulmonary Veins ◽  
High Density ◽  
Congenital Defects ◽  
Density Mapping ◽  
Mapping System ◽  
Oblique Incision ◽  
Pace Maker ◽  
The Right

Abstract Background The biatrial trans-septal approach (BTSa) ameliorates mitral valve (MV) exposure in difficult cases when routine left atriotomy doesnt"t allow it. Main steps are an oblique incision on the right atrium (RA), reaching medially the right pulmonary veins (PV), a septal incision from the fossa ovalis, extended up to reach the first incision, then on the left atrium (LA). Purpose We aim to study the arrhythmic burden in this post-surgical context, focusing on atrial tachycardia (AT), to investigate the complexity of several possible circuits. Methods All patients (&gt;18yo) with previous MV surgery via BTSa for MV repair or replacement, who underwent ablation of AT from January 2017 to September 2019, were enrolled. Patients ablated for persistent or paroxysmal AF, or with AF during the index procedure were excluded. Patients with associated surgery on other valves or congenital defects, coronary, surgical or percutaneous rhythm interventions weren’t excluded. Electroanatomical mapping was created using 2 different high-density mapping system. Substrate and activation map and radio-frequency (RF) ablation (25-50W, Ablation Index target 400) were realized. Cartographies were analysed to evaluate AT re-entry circuit, critical isthmus (CI) location and characterization, atrial vulnerability. Procedural outcomes (AT termination, sinus rhythm (SR) restoration, anti-arrhythmic drugs (AAD) withdrawal), and peri-procedural complications were also evaluated. Results We enrolled 49 patients (median age 57 ± 15), finding a maximum of 5 AT per procedure (2 ± 1). A total of 112 AT were mapped: the majority (72%) were persistent AT, 8,2% common atrial flutter. Cycle length was 314 ± 74 msec, with proximal-distal activation of coronary sinus (78%). A multiple re-entry circuit was observed in 70% of index AT. We identified 152 critical isthmus (maximum 5 per procedure). Only 27,9% of our patients had a single CI; CTI was the most frequent one (n = 37), envolved in 33% of all AT, while BTS scars altogether were envolved in 65% AT. A complete AT circuit was mapped in the RA, the LA and both atria in respectively 49%, 11,5% and 39%AT. The distribution of CIs is shown in figure 1. Biatrial and left AT leads to superior procedure, RF and fluoroscopy duration (p &lt;0,05). SR was restored in 93,4%of patients, requiring a DC shock in 4 cases. Immediate AAD withdrawal was achieved after 41%procedures. No pericardial, oesophageal, vascular or phrenic complication occurred. 4 pace-maker implantations were realized because of 3 interatrial, 2 AV block and a sinus node dysfunction. Conclusions AT occurring after a BTSa have a high prevalence of multiple re-entry circuits with multiple critical isthmus. Ablation in this context is feasible and safe but often requires a left atrial access. Mapping of both atria should be considered to identify critical isthmus and tailored ablation strategy. Abstract Figure 1. Critical Isthmus Distribution

Group Differences in Alcohol-Creativity Interactions

1994 ◽  
Vol 75 (3_suppl) ◽  
pp. 1635-1638 ◽  
Author(s):  
Geoff Lowe
Keyword(s):  
Body Weight ◽  
Repeated Measures ◽  
Group Differences ◽  
Placebo Condition ◽  
Significant Group ◽  
Social Drinkers ◽  
Alcohol Dose

A repeated-measures, balanced-order design was used to test for the effects of alcohol on creativity as measured by verbal forms of the Torrance Creativity Test. Social drinkers (8 men and 8 women) performed under 2 conditions, alcohol (dose = 0.83 ml ethanol/kg body weight) and a placebo. Significant group differences in the alcohol-creativity interaction were noted in that the performance of higher-scoring (in the placebo condition) subjects was impaired by alcohol whereas that of lower-scoring subjects was enhanced.

Mental Fatigue Reduces the Benefits of Self-Controlled Feedback on Learning a Force Production Task

2021 ◽  
pp. 003151252110373
Author(s):  
Milad Khojasteh Moghani ◽  
Rasool Zeidabadi ◽  
Mohammad Reza Shahabi Kaseb ◽  
Iman Bahreini Borujeni
Keyword(s):  
Repeated Measures ◽  
Transfer Test ◽  
Force Production ◽  
Mental Fatigue ◽  
The Self ◽  
Acquisition Phase ◽  
Production Task ◽  
Significant Group ◽  
The Impact ◽  
Force Production Task

This study investigated the impact of mental fatigue and self-controlled versus yoked feedback on learning a force production task. We randomly assigned 44 non-athlete male students (Mage = 21.4, SD = 1.4 years) to four groups; (a) MF&SCF = mental fatigue & self-controlled feedback, (b) MF&Y = mental fatigue & yoked, (c) NMF&SCF = no mental fatigue & self-controlled feedback, and (d) NMF&Y = no mental fatigue & yoked). SCF group participants were provided feedback whenever they requested it, while YK group participants received feedback according to a schedule created by their SCF counterparts. To induce mental fatigue, participants performed a Stroop color-word task for one hour. During the acquisition (practice) phase, participants were asked to produce a given percentage of their maximum force (20%) in 12 blocks of six trials. We recorded the participants’ absolute error at the end of the acquisition phase, the immediate retention test, the first transfer test, and the second transfer test (after 24 hours and without any further mental fatigue). The acquisition phase data were analyzed in a 2 (feedback) × 2 (mental fatigue) × 12 (block) ANOVA with repeated measures on the last factor, while the retention and transfer data were analyzed in 2 (feedback) × 2 (mental fatigue) ANOVAs. We found that all four groups made significant progress during practice ( p < .001), but there were no significant group differences during this phase ( p>.05). There was a significant interaction effect of self-controlled feedback and mental fatigue at retention ( p = .018) and transfer testing ( p < .001). In the mental fatigue condition, participants in the self-controlled group had poorer learning compared to participants in the yoked group; but when not mentally fatigued, participants in the self-controlled group had better learning than those in the yoked group. These findings suggest that mental fatigue reduces typical advantages of self-controlled feedback in motor learning.

Analysis of the energy harvesting potential–based suspension for truck semi-trailer

2018 ◽  
Vol 233 (11) ◽  
pp. 2955-2969 ◽  
Author(s):  
Mohamed AA Abdelkareem ◽  
Mina MS Kaldas ◽  
Mohamed Kamal Ahmed Ali ◽  
Lin Xu
Keyword(s):  
Ride Comfort ◽  
Simulation Analysis ◽  
Conflict Analysis ◽  
Driving Safety ◽  
Dissipated Energy ◽  
Ride Quality ◽  
Surface Model ◽  
Long Distance ◽  
Class C ◽  
The Right

As the articulated trucks are mainly used for long distance transportations, the design of the suspension system became a major concern and a research hotspot not only for ride comfort and driving safety but also for energy consumption. Therefore, the objective of this study is to conduct a comprehensive parametrical–based conflict analysis between the ride comfort and road holding together with the potential power of the shock absorbers. The simulation analysis is performed using a 23 degree-of-freedom full truck semi-trailer mathematical model with random road surface model. The bounce and combined excitation modes for the truck model are applied to present the pro and contra of the simplified and realistic analysis. The bounce mode is applied for a road Class C and truck driving speed of 20 m/s, while the combined mode is performed with the same truck-speed but considering a Class C road for the left track and Class D road for the right track considering the time delay between the truck axles. The truck dynamics including the mean potential power, average dynamic tire load and bounce, and pitch and roll accelerations is comprehensively combined in the conflict analysis–based suspension and driving parameters. The obtained simulation results showed that the articulated truck suspension should be designed considering a realistic excitation condition. In contrast to the bounce mode, under the combined road input, the tractor ride quality and road handling performances are improved when a heavily damped suspension is considered. Furthermore, the otherwise dissipated energy through the damping events can reach an overall value between 2 and 4 kW.

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