Transcranial direct current stimulation in pediatric brain: a computational modeling study.

Transcranial direct current stimulation (tDCS) is a method of non-invasive brain stimulation which uses weak electric currents applied on the scalp to modulate activity of underlying brain tissue. In addition to being used as a tool for cognitive neuroscience investigations, tDCS has generated considerable interest for use as a therapeutic modality for neurologic disorders. Though the safety and tolerability of tDCS in adults is well-established, there is little information on the safety of tDCS in children. Because there are differences between children and adults in several key parameters (such as skull thickness and cerebrospinal fluid volume) which affect current flow through the brain, special consideration should be given to the stimulation parameters which are used in a pediatric study population. In this study we present cortical electrical field maps at different stimulation intensities and electrode configurations using a high-resolution-MRI derived finite element model of a typically developing, anatomically normal 12 year old child. The peak electrical fields for a given stimulus intensity in the adolescent brain were twice as high as in the adult brain for conventional tDCS and nearly four times as high for a 4X1 High-Definition tDCS electrode configuration. These data suggest that acceptable tDCS stimulation parameters may be different in children compared to adults, and that further modeling studies are needed to help guide decisions about applied current intensity.