Background: Non-invasive brain stimulation is being increasingly used to interrogate neurophysiology and modulate brain function. Despite the high scientific and therapeutic potential of non-invasive brain stimulation, experience in the developing brain has been limited. Objective: To determine the safety and tolerability of non-invasive neurostimulation in children across diverse modalities of stimulation and pediatric populations. Methods: A non-invasive brain stimulation program was established in 2008 at our pediatric, academic institution. Multi-disciplinary neurophysiological studies included single-and paired-pulse Transcranial Magnetic Stimulation (TMS) methods. Motor mapping employed robotic TMS. Interventional trials included repetitive TMS (rTMS) and transcranial direct current stimulation (tDCS). Standardized safety and tolerability measures were completed prospectively by all participants. Results: Over 10 years, 384 children underwent brain stimulation (median 13 years, range 0.8e18.0). Populations included typical development (n ¼ 118), perinatal stroke/cerebral palsy (n ¼ 101), mild traumatic brain injury (n ¼ 121) neuropsychiatric disorders (n ¼ 37), and other (n ¼ 7). No serious adverse events occurred. Drop-outs were rare (<1%). No seizures were reported despite >100 participants having brain injuries and/or epilepsy. Tolerability between single and paired-pulse TMS (542340 stimulations) and rTMS (3.0 million stimulations) was comparable and favourable. TMS-related headache was more common in perinatal stroke (40%) than healthy participants (13%) but was mild and self-limiting. Tolerability improved over time with side-effect frequency decreasing by >50%. Robotic TMS motor mapping was well-tolerated though neck pain was more common than with manual TMS (33% vs 3%). Across 612 tDCS sessions including 92 children, tolerability was favourable with mild itching/tingling reported in 37%. Conclusions: Standard non-invasive brain stimulation paradigms are safe and well-tolerated in children and should be considered minimal risk. Advancement of applications in the developing brain are warranted. A new and improved pediatric NIBS safety and tolerability form is included.

BackgroundPannexin 1 forms ion and metabolite permeable hexameric channels and is abundantly expressed in the brain. After discovering pannexin 1 expression in postnatal neural stem and progenitor cells we sought to elucidate its functional role in neuronal development.ResultsWe detected pannexin 1 in neural stem and progenitor cells in vitro and in vivo. We manipulated pannexin 1 expression and activity in Neuro2a neuroblastoma cells and primary postnatal neurosphere cultures to demonstrate that pannexin 1 regulates neural stem and progenitor cell proliferation likely through the release of adenosine triphosphate (ATP).ConclusionsPermeable to ATP, a potent autocrine/paracine signaling metabolite, pannexin 1 channels are ideally suited to influence the behavior of neural stem and progenitor cells. Here we demonstrate they play a robust role in the regulation of neural stem and progenitor cell proliferation. Endogenous postnatal neural stem and progenitor cells are crucial for normal brain health, and their numbers decline with age. Furthermore, these special cells are highly responsive to neurological injury and disease, and are gaining attention as putative targets for brain repair. Therefore, understanding the fundamental role of pannexin 1 channels in neural stem and progenitor cells is of critical importance for brain health and disease.

Objectives The COVID-19 pandemic created an environment of restricted access to health and recreation services. Lifestyle habits including sleep, eating, exercise, and screen use were modified, potentially exacerbating adverse mental health outcomes. This study investigates the impact of COVID-19 on lifestyle habits and mental health symptoms in paediatric attention-deficit/hyperactivity disorder (ADHD) in Canada. Methods An online survey was distributed across Canada to caregivers of children with ADHD (children aged 5 to 18 years) assessing depression (PHQ-9), anxiety (GAD-7), ADHD (SNAP-IV), and lifestyle behaviours. Data were analyzed by gender (male/female) and age category (5 to 8, 9 to 12, and 13 to 18 years). Spearman’s correlations between lifestyle habits and mental health outcomes were conducted. Results A total of 587 surveys were completed. Mean child age was 10.14 years (SD 3.06), including 166 females (28.3%). The PHQ-9 and GAD-7 indicated that 17.4% and 14.1% of children met criteria for moderately severe to severe depression and anxiety symptoms respectively. Children met SNAP-IV cut-off scores for inattention (73.7%), hyperactivity/impulsivity (66.8%), and oppositional defiant disorder (38.6%) behaviours. Caregivers reported changes in sleep (77.5%), eating (58.9%), exercise (83.7%), and screen use (92.9%) in their ADHD child, greatly impacting youth. Sleeping fewer hours/night, eating more processed foods, and watching TV/playing videogames &gt;3.5 hours/day correlated with greater depression, anxiety and ADHD symptoms, and exercising &lt;1 hour/day further correlated with depression symptoms (P&lt;0.01). Conclusions The COVID-19 pandemic has resulted in less healthy lifestyle habits and increased mental health symptoms in Canadian children with ADHD. Longitudinal studies to better understand the relationship between these factors are recommended.

Background: Major depressive disorder (MDD) is common in youth and treatment options are limited. We evaluated the effectiveness and safety of repetitive transcranial magnetic stimulation (rTMS) in adolescents and transitional aged youth with treatment resistant MDD. Methods: Thirty-two outpatients with moderate to severe, treatment-resistant MDD, aged 13–21 years underwent a three-week, open-label, single center trial of rTMS (ClinicalTrials.gov identifier NCT01731678). rTMS was applied to the left dorsolateral prefrontal cortex (DLPFC) using neuronavigation and administered for 15 consecutive week days (120% rest motor threshold; 40 pulses over 4 s [10 Hz]; inter-train interval, 26 s; 75 trains; 3,000 pulses). The primary outcome measure was change in the Hamilton Depression Rating Scale (Ham-D). Treatment response was defined as a >50% reduction in Ham-D scores. Safety and tolerability were also examined. Results: rTMS was effective in reducing MDD symptom severity ( t = 8.94, df = 31, p < 0.00001). We observed 18 (56%) responders (≥ 50% reduction in Ham-D score) and 14 non-responders to rTMS. Fourteen subjects (44%) achieved remission (Ham-D score ≤ 7 post-rTMS). There were no serious adverse events (i.e., seizures). Mild to moderate, self-limiting headaches (19%) and mild neck pain (16%) were reported. Participants ranked rTMS as highly tolerable. The retention rate was 91% and compliance rate (completing all study events) was 99%. Conclusions: Our single center, open trial suggests that rTMS is a safe and effective treatment for youth with treatment resistant MDD. Larger randomized controlled trials are needed. Clinical Trial Registration: www.ClinicalTrials.gov , identifier: NCT01731678