title: Pediatric stroke and transcranial direct current stimulation: methods for rational individualized dose optimization.
abstract: BACKGROUND
  Transcranial direct current stimulation (tDCS) has been investigated mainly in adults and doses may not be appropriate in pediatric applications. In perinatal stroke where potential applications are promising, rational adaptation of dosage for children remains under investigation.
  
  
  OBJECTIVE
  Construct child-specific tDCS dosing parameters through case study within a perinatal stroke tDCS safety and feasibility trial.
  
  
  METHODS
  10-year-old subject with a diagnosis of presumed perinatal ischemic stroke and hemiparesis was identified. T1 magnetic resonance imaging (MRI) scans used to derive computerized model for current flow and electrode positions. Workflow using modeling results and consideration of dosage in previous clinical trials was incorporated. Prior ad hoc adult montages vs. de novo optimized montages provided distinct risk benefit analysis. Approximating adult dose required consideration of changes in both peak brain current flow and distribution which further tradeoff between maximizing efficacy and adding safety factors. Electrode size, position, current intensity, compliance voltage, and duration were controlled independently in this process.
  
  
  RESULTS
  Brain electric fields modeled and compared to values previously predicted models (Datta et al., 2011; Minhas et al., 2012). Approximating conservative brain current flow patterns and intensities used in previous adult trials for comparable indications, the optimal current intensity established was 0.7 mA for 10 min with a tDCS C3/C4 montage. Specifically 0.7 mA produced comparable peak brain current intensity of an average adult receiving 1.0 mA. Electrode size of 5 × 7 cm(2) with 1.0 mA and low-voltage tDCS was employed to maximize tolerability. Safety and feasibility confirmed with subject tolerating the session well and no serious adverse events.
  
  
  CONCLUSIONS
  Rational approaches to dose customization, with steps informed by computational modeling, may improve guidance for pediatric stroke tDCS trials.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Program in Physical Therapy, University of Minnesota, Medical School Minneapolis, MN, USA.
authors.forename: Bernadette T
authors.initials: BT
authors.lastname: Gillick
authors.affiliation: Alberta Children's Hospital Research Institute, University of Calgary Calgary, AB, Canada.
authors.forename: Adam
authors.initials: A
authors.lastname: Kirton
authors.affiliation: Weill-Cornell Medical College, Burke Medical Research Institute White Plains, NY, USA.
authors.forename: Jason B
authors.initials: JB
authors.lastname: Carmel
authors.affiliation: Department of Biomedical Engineering, The City College of New York of CUNY New York, NY, USA.
authors.forename: Preet
authors.initials: P
authors.lastname: Minhas
authors.affiliation: Department of Biomedical Engineering, The City College of New York of CUNY New York, NY, USA.
authors.forename: Marom
authors.initials: M
authors.lastname: Bikson
keywords: hemiparesis; modeling; pediatrics; stroke; transcranial direct current stimulation