Rapid intervention team strategy improves intervention quality for patients undergoing hemodialysis with arteriovenous shunt dysfunction or failure.

BACKGROUND: Vascular access dysfunction is a great burden for hemodialysis patients. Early intervention of a dysfunctional arteriovenous shunt is associated with higher technical success and may improve midterm patency. This trial aimed to estimate the feasibility of a new system, the "rapid intervention team" (RIT) strategy. METHODS: We recruited hemodialysis patients who visited our hospital because of arteriovenous shunt dysfunction or failure to undergo an RIT strategy from September 1, 2019 to December 31, 2022. In addition, we included a control group comprising patients who underwent percutaneous intervention for arteriovenous shunt dysfunction or failure before this strategy was implemented from February 1, 2017 to December 31, 2022. Case number, time to intervention, all-cause mortality, cumulative survival rate, and number of patients who required temporary dialysis catheter insertion and recreation were compared between the two groups. The primary endpoints were double-lumen insertion, a composite outcome involving permanent catheter insertion, and the need for recreation. The secondary endpoint was all-cause mortality. RESULTS: We enrolled 1054 patients, including 544 (51.6%) and 510 (48.4%) in the RIT and control groups, respectively. Even with the coronavirus disease of 2019 (COVID-19) pandemic, the number of cases significantly increased after the implementation of the RIT strategy (from 216 in 2019 to 828 in 2022, p for trend <0.001). The RIT group had a shortened time to intervention ( p for trend <0.001). The implementation of the RIT strategy was significantly associated with a reduced risk of insertion of a temporary double-lumen catheter and recreation of vascular access (1% vs 6% and 1% vs 28%, respectively; both p < 0.01). The cumulative survival rate was not significantly different between the RIT and control groups ( p = 0.16). CONCLUSION: The implementation of the RIT strategy improves the quantity and quality of percutaneous transluminal intervention for arteriovenous shunt dysfunction or failure in patients undergoing hemodialysis.

Probing the inhibitory motor circuits in adductor laryngeal dystonia during a dystonia-unrelated task.

BACKGROUND: The pathophysiology of adductor laryngeal dystonia (AdLD) remains unknown; however, there is growing evidence that dystonia is associated with disruptions in the inhibitory regulation of sensorimotor cortical areas. Using functional MRI (fMRI) and transcranial magnetic stimulation (TMS) complementarily, we previously demonstrated an overly activated laryngeal motor cortex and revealed correlations between blood-oxygen-level dependent (BOLD) activation and intracortical inhibition in a phonation (dystonia-related) task in adductor laryngeal dystonia (AdLD). OBJECTIVE: Here, we aimed to characterize the brain-based findings in the primary motor cortex (M1) during a dystonia-unrelated (finger tapping) task in AdLD and controls (CTL). METHODS: We examined the between-group differences in task-dependent BOLD activation and intracortical inhibition, measured by the TMS-evoked cortical silent period (cSP), in the M1. The correlations between fMRI and TMS responses were assessed. RESULTS: There is more broadly dispersed BOLD activation, not confined to the hand motor cortex, and reduced intracortical inhibition in AdLD compared to CTL. Further, there are more positive correlations between cSP and BOLD activation in a task unrelated to dystonic symptoms in AdLD compared with CTL. This is in contrast to our previous work that demonstrated fewer positive correlations in AdLD during a dystonic phonation task. CONCLUSIONS: In unaffected musculature activation, there is dispersed BOLD activation that is correlated with intracortical inhibition suggesting a possible compensatory strategy in the non-dystonic muscles.

The effects of continuous oromotor activity on speech motor learning: speech biomechanics and neurophysiologic correlates.

Sustained limb motor activity has been used as a therapeutic tool for improving rehabilitation outcomes and is thought to be mediated by neuroplastic changes associated with activity-induced cortical excitability. Although prior research has reported enhancing effects of continuous chewing and swallowing activity on learning, the potential beneficial effects of sustained oromotor activity on speech improvements is not well-documented. This exploratory study was designed to examine the effects of continuous oromotor activity on subsequent speech learning. Twenty neurologically healthy young adults engaged in periods of continuous chewing and speech after which they completed a novel speech motor learning task. The motor learning task was designed to elicit improvements in accuracy and efficiency of speech performance across repetitions of eight-syllable nonwords. In addition, transcranial magnetic stimulation was used to measure the cortical silent period (cSP) of the lip motor cortex before and after the periods of continuous oromotor behaviors. All repetitions of the nonword task were recorded acoustically and kinematically using a three-dimensional motion capture system. Productions were analyzed for accuracy and duration, as well as lip movement distance and speed. A control condition estimated baseline improvement rates in speech performance. Results revealed improved speech performance following 10 min of chewing. In contrast, speech performance following 10 min of continuous speech was degraded. There was no change in the cSP as a result of either oromotor activity. The clinical implications of these findings are discussed in the context of speech rehabilitation and neuromodulation.

Relationship between interhemispheric inhibition and bimanual coordination: absence of instrument specificity on motor performance in professional musicians.

Functional reorganization in a musician's brain has long been considered strong evidence of experience-dependent neuroplasticity. Highly coordinated bimanual movements require abundant communication between bilateral hemispheres. Interhemispheric inhibition (IHI) is the communication between bilateral primary motor cortices, and there is beginning evidence to suggest that IHI is modified according to instrument type, possibly due to instrument-dependent motor training. However, it is unknown whether IHI adaptations are associated with non-musical bimanual tasks that resemble specific musical instruments. Therefore, we aimed to investigate the relationship between IHI and bimanual coordination in keyboard players compared with string players. Bimanual coordination was measured by a force tracking task, categorized as symmetric and asymmetric conditions. Ipsilateral silent period (iSP) was obtained using transcranial magnetic stimulation to index IHI in both left (L) and right (R) hemispheres. Canonical correlation analysis was performed to identify linear relationships between the IHI and bimanual coordination outcomes. There was no difference in bimanual coordination outcomes between keyboard and string players. Increased iSP from the L to R hemisphere was found in string players compared to keyboard players. There appeared to be different instrument-dependent relationships between IHI and bimanual coordination, regardless of symmetric or asymmetric task. Laboratory motor assessments resembling specific features of musical instruments (symmetric vs. asymmetric hand use) did not distinctly characterize bimanual motor skills between keyboard and string players. The relationships between IHI and bimanual coordination in these two instrument types were independent of task condition. Instrument-dependent neuroplasticity may be evident only within the context of musical instrument playing.

Relationship between Interhemispheric Inhibition and Dexterous Hand Performance in Musicians and Non-musicians.

Interhemispheric inhibition (IHI) is essential for dexterous motor control. Small previous studies have shown differences in IHI in musicians compared to non-musicians, but it is not clear whether these differences are robustly linked to musical performance. In the largest study to date, we examined IHI and comprehensive measures of dexterous bimanual performance in 72 individuals (36 musicians and 36 non-musicians). Dexterous bimanual performance was quantified by speed, accuracy, and evenness derived from a series of hand tasks. As expected, musicians significantly outperformed non-musicians. Surprisingly, these performance differences could not be simply explained by IHI, as IHI did not significantly differ between musicians and non-musicians. However, canonical correlation analysis revealed a significant relationship between combinations of IHI and performance variables in the musician group. Specifically, we identified that IHI may contribute to the maintenance of evenness regardless of speed, a feature of musical performance that may be driven by practice with a metronome. Therefore, while IHI changes by themselves may not be sufficient to explain superior hand dexterity exhibited by musicians, IHI may be a potential neural correlate for specific features of musical performance.

Measuring ipsilateral silent period: Effects of muscle contraction levels and quantification methods.

Ipsilateral silent period (iSP) is a frequently measured index of interhemispheric inhibition. However, the methodology used across studies has been inconsistent and variable. We investigated the optimal contraction level and quantification methods for achieving iSP measurement consistency. Twenty-five healthy adults performed right isometric thumb abduction under three conditions (30%, 50%, and 100% of maximal voluntary contraction) while transcranial magnetic stimulation was applied over the primary motor cortex representational area of the abductor pollicis brevis. iSP was quantified by: iSP duration, iSP area and normalized iSP. Measurement consistency was determined by the homogeneity of variance test and by the coefficient of variation. iSP was consistent across all contraction levels when measured by iSP duration and normalized iSP. Normalized iSP showed the least measurement variability. We propose that future investigations examining interhemispheric inhibition use normalized iSP for measurement consistency and the ability to compare results across studies.

Evidence of altered corticomotor excitability following targeted activation of gluteus maximus training in healthy individuals.

It has been proposed that strengthening and skill training of gluteus maximus (GM) may be beneficial in treating various knee injuries. Given the redundancy of the hip musculature and the small representational area of GM in the primary motor cortex (M1), learning to activate this muscle before prescribing strength exercises and modifying movement strategy would appear to be important. This study aimed to determine whether a short-term activation training program targeting the GM results in neuroplastic changes in M1. Using transcranial magnetic stimulation, motor evoked potentials (MEPs) were obtained in 12 healthy individuals at different stimulation intensities while they performed a double-leg bridge. Participants then completed a home exercise program for ∼1 h/day for 6 days that consisted of a single exercise designed to selectively target the GM. Baseline and post-training input-output curves (IOCs) were generated by graphing average MEP amplitudes and cortical silent period durations against corresponding stimulation intensities. Following the GM activation training, the linear slope of both the MEP IOC and cortical silent period IOC increased significantly. Short-term GM activation training resulted in a significant increase in corticomotor excitability as well as changes in inhibitory processes of the GM. We propose that the observed corticomotor plasticity will enable better utilization of the GM in the more advanced stages of a rehabilitation/training program.

Characteristics of nonylphenol and bisphenol A accumulation by fish and implications for ecological and human health.

Fish populations constitute an important part of aquatic ecosystems. Thus, their accumulation of nonylphenol (NP) and bisphenol A (BPA) may pose risks to ecosystems and human health. This study analyzed the concentrations of NP and BPA in four types of fishes (i.e., wild/farmed freshwater fishes and wild/farmed marine fishes). Wild freshwater fishes contained higher concentrations of NP and BPA than the other three types of fishes. The concentrations of NP in the wild freshwater fishes ranged from 1.01 to 277 µg/kg ww, with bioconcentration factors (BCFs) and biota-sediment accumulation factors (BSAFs) ranging from 74.0 to 2.60 × 10(4)L/kg and from 0.003 to 18.3, respectively. The wild freshwater fishes contained relatively low amounts of BPA, varying from ND to 25.2 µg/kg ww, with the BCFs and BSAFs ranging from 1.00 to 274L/kg and from 0.003 to 3.40, respectively. Five fish species particularly showed high BCFs and BSAFs, indicating that they could be an important source of NP for higher trophic levels, most likely resulting in ecological risks. The demersal fishes showed a greater ability to accumulate NP than the pelagic ones. The fact that the 95th percentile values of the risk quotient (RQ) for NP and BPA were higher than the acceptable threshold indicated that these two compounds would have adverse effects on aquatic organisms in Taiwanese rivers. The consumption of wild marine fishes had the highest 95th percentile values of hazard quotient (HQ) for NP and BPA among the four types of fishes, particularly for the population aged 0-3 years. However, the 95th percentile values of HQ for NP and BPA were all less than 1, suggesting that exposure to NP and BPA through fish consumption posed no remarkable risk to human health in Taiwan.

The potential role of water quality parameters on occurrence of nonylphenol and bisphenol A and identification of their discharge sources in the river ecosystems.

Nonylphenol (NP) and bisphenol A (BPA) have attracted great attention due to their estrongenic activities and occurrence in different environments. This study investigated concentrations of NP and BPA in water and sediments of 16 major rivers in Taiwan to determine their association with water quality parameters on their distribution. The sources of NP and BPA discharged into river environments were also identified. The results showed that concentrations of NP and BPA were in the range of 0.02-3.94 and 0.01-44.65µgL(-1) in water and 6.59-47797.69 and 0.37-491.54µgkg(-1) dry weight in sediments. High levels of NP and BPA in water and sediments were measured in sampling sites near highly industrialized and urbanized areas. Construction of the sewage system and wastewater treatment plant has decreased these chemicals discharged into Love River. Dilution effects and erosion of surface sediments in the high-flow season resulted in lower concentrations of NP and BPA detected in sediments of most rivers than those in the low-flow season. Occurrence characteristics of NP and BPA in water and sediments were mainly related to organic carbon contents in sediments and several water quality parameters such as dissolved oxygen, pH, concentrations of ammonia-nitrogen and total organic carbon in water. Effluents from NP/BPA-related factories appeared to be the major discharge sources of NP and BPA. Use and waste of BPA-containing products in household activity was the another discharge source of BPA, but handling NP-containing products became an important source of NP only in the low-flow season.