Accelerating Motor Learning in Pediatrics
Condition: Healthy; Pediatrics
Study type: Interventional

Summary: 
      Non-invasive brain stimulation can both study and potentially treat neurological disorders.
      Transcranial direct-current stimulation (tDCS) is an emerging safe and tolerability form of
      stimulation and has been used increasingly over the last decade.

      The purpose of this research is to see if two different types of tDCS can improve motor
      function in healthy children. tDCS has been shown to safely enhance hand motor function in
      healthy adults, and those that have suffered stroke and other conditions. Recently the
      investigators demonstrated that tDCS may enhance hand motor function in healthy children,
      however, how it does so is unknown. In addition to assessing changes in motor function when
      tDCS is given during motor skill training, the investigators will perform various tests
      before and after stimulation to understand the changes that happen in the brain accompanying
      motor skill learning and brain stimulation.

      The investigators hypothesize that there will be an accelerated acquisition of motor skill,
      when training is paired with conventional anodal tDCS, HD-tDCS, or sham tDCS.
    

Detailed description: 
      Background & rationale: Plasticity may be enhanced in the developing brain but mechanisms are
      poorly understood. Brain stimulation technologies such as transcranial direct-current
      stimulation (tDCS) modulate motor cortex excitability and plasticity. Studies by our group
      and others suggest that neuromodulation trials with tDCS are both safe and feasible in
      children. Recently the investigators demonstrated that conventional tDCS can enhance motor
      learning in healthy children. Additionally, recent advances in high-definition tDCS (HD-tDCS)
      have presented an opportunity to focally stimulate regions of the brain. HD-tDCS has not been
      investigated to date in children.

      Establishing an ability of tDCS to enhance motor learning has therapeutic implications for
      children with motor disabilities. Perinatal stroke is the leading cause of hemiparetic
      cerebral palsy and most survivors suffer lifelong physical disability. Emerging models from
      our lab and others have defined central therapeutic targets whereby brain stimulation may
      enhance motor learning and function. Understand the effects of tDCS on motor learning, and
      it's underlying changes within the brain, is essential to advancing such interventions.

      Research question & objectives: Here the investigators propose to characterize the effects of
      tDCS on motor learning in healthy children. The primary objective of this study is to
      determine changes in acquisition of motor skill, when training is paired with conventional
      anodal tDCS, HD-tDCS, or sham tDCS. Multiple secondary objectives will describe biochemical
      and sensorimotor changes in the brain that take place during motor learning paired with tDCS.
      Secondary objectives will also assess the safety of HD- tDCS in healthy children.

      Ethics: This study has been approved by the University of Calgary Research Ethics Board.

      Design: Randomized, double blind, sham-controlled trial to evaluate the ability of tDCS and
      HD-tDCS to enhance motor learning.

      Methods: Children will be recruited through the Healthy Infants and Children Clinical
      Research Program.

      The training task will consists of performing the Purdue Pegboard Test (PPTL) with their left
      hand. This simple motor learning task is a well-validated task for complex, functionally
      relevant motor learning. The PPTL has demonstrated good sensitivity to change in both healthy
      and disease motor learning studies in adults and school-aged children. The PPTL will be
      performed over five consecutive days to monitor motor learning.

      Children will attend the Alberta Children's Hospital Non-Invasive Brain Stimulation
      Laboratory. Subjects will be randomized to one of three stimulation groups (sham tDCS,
      conventional anodal tDCS, HD-tDCS). Baseline measures will be performed, including: magnetic
      resonance neuroimaging (anatomical imaging, functional neuroimaging and magnetic resonance
      spectroscopy), transcranial magnetic stimulation neurophysiology (motor mapping of the left
      and right motor cortex), sensorimotor functional changes assessed using the Kinesiological
      Instrument for Normal and Altered Reaching Movements (KINARM; arm positioning matching,
      kinesthesia, visually guided reaching, and object hit task), motor function changes (PPT,
      Jebsen-Taylor Test, Serial Reaction Time Task), and sensory discrimination measures
      (amplitude discrimination, temporal order judgment, temporal order judgment task, duration
      discrimination task, duration discrimination with confound, and single site adaptation task.

      Following baseline measures, subjects will be seating in a comfortable chair with the PPTL
      test in front of them on a table. Participant randomized to sham or conventional anodal tDCS
      will be fitted with two 25cm2 electrodes (anode over the right primary motor cortex, cathode
      over the contralateral supraorbital area) or an EEG cap containing four small circular
      electrode (HD-tDCS, 1 anode centered over the right primary motor cortex, 4 cathodes surround
      the anode in a ring-like fashion). Three pre-intervention trials of the PPTL will be
      performed. All subjects will then have the tDCS ramped up to 1milliamp over 45 seconds. After
      120 seconds the current will either be ramped down to 0milliamp (sham tDCS) or continue for a
      total of 20 minutes. The PPTL will be performed 5, 10, and 15 minutes following stimulation
      commencement, and after stimulation has ended (3 repetitions per time point). A tDCS safety
      and tolerability questionnaire will then be completed.

      The same tDCS-treatment, PPTL training and safety and tolerability questionnaires will be
      performed over the next three consecutive days. On study day 5 participants will again repeat
      PPTL training paired with tDCS-treatment. Following tDCS and PPTL training, magnetic
      resonance neuroimaging, transcranial magnetic stimulation neurophysiology, sensorimotor
      functional changes, motor function changes, and sensory discrimination measures will be
      repeated to assess changes induced by motor learning and tDCS.

      Participants will return six weeks following training, where magnetic resonance neuroimaging,
      transcranial magnetic stimulation neurophysiology, sensorimotor functional changes, motor
      function changes, and sensory discrimination measures will be repeated to assess long-term
      changes.

      Data analysis: All outcome variables will be compared across the three intervention groups
      (sham tDCS, conventional tDCS, HD- tDCS) using a two-way repeated measures ANOVA with
      appropriate post-hoc analysis. The repeated measures ANOVA will distinguish the influence of
      intervention (stimulation type) and time (baseline, post-training, 1 month post- training).
      Pearson's correlations will be performed between the primary outcome measure and secondary
      outcome measures. Secondary statistical analysis will be performed as warranted.
    

Intervention name(s): Anodal Conventional tDCS; Anodal High Definition tDCS; Sham tDCS
Intervention type(s): Device; Device; Device
Intervention description(s): tDCS will be applied for 20 minutes at 1milliamp while participants are performing a fine motor task. The current will be set at 1milliamp, stimulation will be ramped up over 30 seconds and ramped down over 30 seconds.; HD-tDCS will be applied for 20 minutes at 1milliamp while participants are performing a fine motor task. The current will be set at 1milliamp, stimulation will be ramped up over 30 seconds and ramped down over 30 seconds.; tDCS will be applied for 1 minutes at 1milliamp while participants are performing a fine motor task. The current will be set at 1milliamp, stimulation will be ramped up over 30 seconds and ramped down over 30 seconds.
Other intervention name(s): Direct-current stimulator (Soterix); Direct-current stimulator (Soterix); Direct-current stimulator (Soterix)
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Participants will be assigned to one of three groups (sham, tDCS, HD-tDCS) throughout the duration of the study.
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Other
Keywords: Anodal Stimulation Transcranial Direct Current Stimulation; High-Definition Transcranial Direct Current Stimulation; tDCS; Non-invasive brain stimulation; Pediatrics