Intensity-dependent effects of transcranial pulsed current stimulation on interhemispheric connectivity: a high-resolution qEEG, sham-controlled study.

Defining optimal parameters for stimulation is a critical step in the development of noninvasive neuromodulation techniques. Transcranial pulsed current stimulation (tPCS) is emerging as another option in the field of neuromodulation; however, little is known about its mechanistic effects on electrical brain activity and how it can modulate its oscillatory patterns. The aim of this study was to identify the current intensity needed to exert an effect on quantitative electroencephalogram (qEEG) measurements. Forty healthy volunteers were randomized to receive a single session of sham or active stimulation at 0.2, 1, or 2 mA current intensity with a random frequency with an oscillatory pulsed range between 1 and 5 Hz. We conducted an exploratory frequency domain analysis to detect changes in absolute power for theta, alpha, and beta frequency bands and also interhemispheric coherence for alpha, theta, and four different sub-bands. Cognitive and nonspecific adverse effects were also recorded. Our results showed that both 1 and 2 mA can modulate interhemispheric coherence at the fronto-temporal areas for the theta band as compared with sham, while 2 mA also increased the low-beta and high-beta interhemispheric coherence at the same anatomical location. There were no group differences for adverse effects and participants could not guess correctly whether they received active versus sham stimulation. On the basis of our results, we conclude that tPCS is associated with an intensity-dependent facilitatory effect on interhemispheric connectivity. These results can guide future tPCS applications and will define its role as a neuromodulatory technique in the field.

Clinical research in pediatric organ transplantation.

Solid organ transplantation has greatly improved survival in children with end-stage disease, becoming one of the main treatment options in this population. Nonetheless, there are significant challenges associated with validating and optimizing the effects of these interventions in clinical trials. Therefore, we reviewed the main issues related to conducting clinical transplantation research in children. We divided these challenges into three different categories: (i) challenges related to surgical techniques and anesthetic procedures, (ii) challenges related to post-transplant care and (iii) challenges specific to a particular population group and disease type. Some of the observed burdens for clinical research in this field are related to the limitations of conducting studies with a placebo or sham procedure, determining the standard of care for a control group, low prevalence of cases, ethical concerns related to use of a placebo control group and lack of generalizability from animal studies and clinical trials conducted in adult populations. To overcome some of these barriers, it is necessary to utilize alternative clinical trial designs, such as observational studies or non-inferiority trials, and to develop multicenter collaborations to increase the recruitment rate. In conclusion, the lack of robust data related to pediatric transplantation remains problematic, and further clinical trials are needed to develop more efficacious and safer treatments.

Clinical research in pediatric organ transplantation

Solid organ transplantation has greatly improved survival in children with end-stage disease, becoming one of the main treatment options in this population. Nonetheless, there are significant challenges associated with validating and optimizing the effects of these interventions in clinical trials. Therefore, we reviewed the main issues related to conducting clinical transplantation research in children. We divided these challenges into three different categories: (i) challenges related to surgical techniques and anesthetic procedures, (ii) challenges related to post-transplant care and (iii) challenges specific to a particular population group and disease type. Some of the observed burdens for clinical research in this field are related to the limitations of conducting studies with a placebo or sham procedure, determining the standard of care for a control group, low prevalence of cases, ethical concerns related to use of a placebo control group and lack of generalizability from animal studies and clinical trials conducted in adult populations. To overcome some of these barriers, it is necessary to utilize alternative clinical trial designs, such as observational studies or non-inferiority trials, and to develop multicenter collaborations to increase the recruitment rate. In conclusion, the lack of robust data related to pediatric transplantation remains problematic, and further clinical trials are needed to develop more efficacious and safer treatments.