P180 Non-invasive brain stimulation is safe in children: Evidence from 2.5 million stimulations

Introduction Non-invasive brain stimulation can interrogate neurophysiology and therapeutically modulate brain function. Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are the primary modalities. Despite such potential, experience in the developing brain has been limited. Objective Assess safety and tolerability of non-invasive brain stimulation in children. Methods Our academic pediatric center established a non-invasive brain stimulation laboratory for children in 2008. Multi-disciplinary neurophysiological studies included single- and paired-pulse TMS methods. Therapeutic clinical trials used repetitive TMS (rTMS) and anodal/cathodal motor cortex tDCS. Prospectively collected safety and tolerability data on all subjects included a previously developed pediatric TMS safety and tolerability measure, child and parental interviews, and data safety and monitoring boards. Results From 2008–2016, 282 children underwent brain stimulation (median 11.2 years, range 0.7–18). Most common were perinatal stroke/cerebral palsy (70), mild traumatic brain injury (TBI, 68), or typically developing (53). There were no serious adverse events. Tolerability between TMS (402,680 stimulations) and rTMS (2.1million stimulations) was comparable and rated similar to a long car ride. Although >100 had brain injuries and/or epilepsy, no seizures occurred. Headache following a TMS neurophysiology protocol was more common in perinatal stroke (40%) than typically developing (13%) participants but was mild and self-limiting. Mild neck pain with was relatively common but comparable between perinatal stroke (22%), depression (19%), and TBI (19%). Tolerability improved over time with rates of headache, neck pain, and unpleasant tingling decreasing by >50% at repeat testing. One adolescent with depression withdrew from a high-frequency rTMS trial for discomfort. Of 51 children receiving tDCS, scalp itching in 55% was mild, transient, and comparable to sham with no drop-outs. Neither low frequency rTMS nor cathodal tDCS of the non-lesioned hemisphere decreased function of either hand in children with hemiparetic cerebral palsy. Conclusions Brain stimulation is safe and well tolerated in children. Applications in the developing brain should be advanced.