Post initial screening and baseline data collection, all study participants (a single cohort of patients) will receive a single dose of sham tDCS for 20 minutes over the left dorsolateral prefrontal cortex (DLPFC) or the primary motor cortex in conjunction with Mozart piano sonata. For sham tDCS, the current will be ramped up and immediately ramped down for 30 seconds. The sham tDCS session will be preceded and followed by behavioral assessments.

Post sham-tDCS, we will determine the eligibility of the participant to receive 1 mA of real tDCS based on the occurrence of adverse events and seizures occurring within 5 days of the sham session. After a minimum of 5 days post-sham stimulation (and typically around 7 days later), the participant will receive a single dose of 1-mA current (for head circumference >52 cm; children with head circumference 43-52cm will receive 0.5-mA) over left DLPFC or M1 in conjunction with Mozart piano sonata. The participant will receive 1-mA current for 20 minutes; the current will be ramped up for 30 seconds, will held constant at the determined intensity for 20 minutes, and then ramped down for 10 seconds. The 1-mA tDCS session will be preceded and followed by behavioral assessments.

Post 1-mA tDCS, we will again determine the eligibility of the participant to receive 2 mA current. After a minimum of 5 days post-1 mA stimulation (typically 7 days), the participant will receive a single dose of 2-mA current (if head circumference >52cm; children with head circumference 43-52cm will receive 1-mA) over left DLPFC or M1 in conjunction with Mozart piano sonata. The participant will receive 2-mA current for 20 minutes; the current will be ramped up for 30 seconds, will held constant at the determined intensity for 20 minutes, and then ramped down for 10 seconds. The 2-mA tDCS session will be preceded and followed by behavioral assessments.

Real and sham tDCS/Mozart piano sonata (K.448)

Adverse Event Form Questionnaire: Assessment of change from baseline and post-sham stimulation to post- stimulation (1 mA, 2 mA) and follow-up using a detailed assessment of participant's symptoms (skin problems and/or seizures) as related to transcranial direct current stimulation (tDCS) intervention.

Face, Legs, Activity, Cry and Consolability Scale (FLACC) Questionnaire: Assessment of change from baseline and post-sham stimulation to pre-during-post stimulation (1 mA, 2 mA) using an observation tool that will measure pain and discomfort as related to transcranial direct current stimulation (tDCS) in children with decreased communication and cognitive impairment.

Questionnaire: Assessment of interruption of inpatient care due to child's participation in the study.

Questionnaire: Assessment to receive feedback about the satisfaction in the study from the parent/guardian/caregiver of the participant.

The information on number of participants with adverse events will be collected from the beginning of sham tDCS until the end of the last tDCS session.

Modified Functional Reach Task, Grooved Pegboard, Digit Span, or Coma-Recovery Scale Revised: Task chosen based on child's functional status and assessment of change from baseline, post-sham stimulation, and pre-stimulations (1 mA, 2 mA).