Combining transcranial direct current stimulation and gravity-supported, computer-enhanced arm training in a chronic pediatric stroke survivor: a case report

Introduction: Transcranial direct current stimulation (tDCS) is a non-invasive method of brain stimulation that modulates cortical excitability via constant weak electric currents. Case presentation: We tested the feasibility and preliminary effects of combined tDCS with repetitive, task-specific practice of the affected upper extremity in a 19-year-old individual with no meaningful use of the right arm due to a chronic left middle cerebral artery infarction at the age of 12 years old. The subject underwent 10 training sessions over 2 weeks during which he received 40 minutes of tDCS while performing repetitive, multidirectional arm reaching and hand grasp/release activities in a gravity-supported, computer-enhanced environment. Potential side effects were investigated using the Digit Span test, the nine-item Patient Health Questionnaire, and the tDCS Adverse Effects Questionnaire. Clinical outcome measures were gathered pre-training, post-training and 2 weeks after the end of training. These measures included (i) the Jebsen-Taylor Hand Function Test, (ii) the Box and Block Test, (iii) the Fugl-Meyer Assessment for upper extremity, and (iv) Motor Activity Log. In addition, during the training sessions, we collected kinematic measures during arm reaching. The subject tolerated the brain stimulation well. There were no effects on mood or working memory. Clinical outcome measures showed improvements in upper extremity motor function that were retained 2 weeks after completion of training. Movement kinematic parameters showed similar trends in response to training: improvements in mean speed, maximum speed, and acceleration of arm reaching movements. Conclusions: Despite the fact that this case report does not detangle the effects of tDCS from motor training, it provides initial detailed clinical and kinematic data showing beneficial effects of tDCS for enhancing motor recovery when combined with Gravity-Supported, Computer-Enhanced Arm Training that are useful for future trials planning the use of this combined approach in pediatric stroke. We review the use of combined robotic-based arm training and tDCS for motor recovery in stroke.