Enhancing Motor Plasticity After Perinatal Stroke Using tDCS

The primary intervention will be cathodal (inhibitory) tDCS over non-lesioned M1. This will be targeted using TMS baseline mapping data and neuronavigation (Brainsight2, Rogue Research, Montreal) individualized to the subjects MRI. Soft, replaceable 25cm2 electrodes will be placed over clean, dry scalp with the cathode over marked M1 and the reference electrode over contralateral forehead/orbit consistent with standard protocols. The current-controlled DC stimulator (neuroConn GmbH, Ilmenau, GE) will be turned up slowly over 30 seconds to the treatment current of 1.0 mA. TDCS will be administered each day during the first 20 minutes of the 90 minute therapy session. Child, family, and both treating and measuring occupational therapists are blinded to treatment allocation.

Sham subjects will undergo exactly the same tDCS protocol as outlined above. This includes the initial stimulation sequence, generating the initial transient scalp sensations identical to the treatment group. The stimulator will be programmed by the technologist to automatically ramp down to off over 30 seconds after 120 seconds of stimulation.