Effects of Transcranial Direct Current Stimulation Combined With Virtual Reality on Balance and Executive Functions in Children With Spastic Diplegic Cerebral Palsy

participants will receive active transcranial direct current stimulation at 1 mA for 20 minutes combined with virtual reality rehabilitation, three sessions per week for six weeks, for a total of 18 sessions.

Active transcranial direct current stimulation will be delivered using saline-soaked sponge electrodes at an intensity of 1 mA for 20 minutes per session. Stimulation will be administered three times per week for six weeks, for a total of 18 sessions, concurrently with virtual reality rehabilitation. The stimulation montage will target the lower-limb motor cortical region with a supraorbital reference electrode.

Virtual reality rehabilitation will be delivered using an interactive motion-based rehabilitation system and will include progressively challenging activities targeting postural control, balance, movement coordination, obstacle navigation, visual attention, dual-task performance, and cognitive-motor integration. Training will be delivered three times per week for six weeks, for a total of 18 sessions. The same VR rehabilitation protocol will be provided in both the active and sham tDCS groups.

• VR Rehabilitation
• Xbox Kinect-Based Virtual Reality Therapy

Participants will receive sham transcranial direct current stimulation using the same electrode setup as the active condition, with brief initial stimulation to mimic active tDCS, combined with the same virtual reality rehabilitation protocol, three sessions per week for six weeks, for a total of 18 sessions.

Virtual reality rehabilitation will be delivered using an interactive motion-based rehabilitation system and will include progressively challenging activities targeting postural control, balance, movement coordination, obstacle navigation, visual attention, dual-task performance, and cognitive-motor integration. Training will be delivered three times per week for six weeks, for a total of 18 sessions. The same VR rehabilitation protocol will be provided in both the active and sham tDCS groups.

• VR Rehabilitation
• Xbox Kinect-Based Virtual Reality Therapy

Sham transcranial direct current stimulation will use the same electrode montage and setup as the active condition. Active current will be delivered only during the initial 30 seconds to reproduce the initial sensory experience of stimulation, after which stimulation will be discontinued while the electrodes remain in place. Sham tDCS will be combined with the same virtual reality rehabilitation protocol as the active tDCS group

Participants will receive conventional physical therapy including lower-limb stretching, strengthening, balance training, motor-control exercises, gait-related training, and functional mobility activities, three sessions per week for six weeks.

Conventional physical therapy will be delivered for approximately 30 minutes per session, three sessions per week for six weeks, for a total of 18 sessions. Treatment will include lower-limb stretching, supported balance and weight-shifting activities, strengthening, motor-control exercises, gait-related training, and progressive functional mobility activities. Exercise difficulty and therapist assistance will be progressed according to participant tolerance and functional ability.

• CPT

Functional balance will be assessed using the Pediatric Balance Scale (PBS), a 14-item clinical measure of balance during functional activities. Each item is scored from 0 to 4, producing a total score ranging from 0 to 56. Higher scores indicate better functional balance. The PBS total score will be assessed at baseline, mid-intervention, and post-intervention.

Dynamic standing balance will be assessed using the Functional Reach Test (FRT). The primary FRT metric will be maximum forward reach distance measured in centimeters while maintaining a stable standing position without taking a step or losing balance. Greater reach distance indicates better dynamic balance. Completion time in seconds will also be recorded as an additional performance metric, with shorter completion time indicating better performance.

Visual attention, processing speed, and cognitive flexibility will be assessed using the Trail Making Test for Children. Completion time for Part A and Part B will be recorded in seconds. Lower completion times indicate faster cognitive performance. The difference between Part B and Part A completion times (B-A) will also be calculated as an index of the additional cognitive-flexibility and set-shifting demand associated with Part B.

Inhibitory control and interference processing will be assessed using a child version of the Stroop Color and Word Test. Performance measures will include word-reading time, color-naming time, color-word interference time, and error score. Completion times will be recorded in seconds, with shorter times indicating faster performance. Fewer errors indicate better inhibitory control and response accuracy.

Attention, short-term memory, and working memory will be assessed using the Digit Span Test. Raw scores will be recorded for Digit Span Forward, Digit Span Backward, Digit Span Sequencing, and the overall Digit Span Total Score. Higher raw scores indicate better attention and working-memory performance.

Lower-limb spasticity will be assessed using the Modified Tardieu Scale (MTS) in the clinically more-spastic index limb. The assessment will characterize velocity-dependent resistance to passive movement across relevant lower-limb muscle groups. Measurements will include the angle of muscle reaction at fast stretch (R1), passive range of motion at slow stretch (R2), and the dynamic component of spasticity calculated as R2 minus R1, expressed in degrees. Quality of muscle reaction will also be recorded where applicable. The same designated index limb will be assessed longitudinally at all study time points.