This study is looking at Parkinson's disease (PD) patients who have trouble with balance and walking. The study involves two groups of PD patients and a group of healthy people. PD patients will be split into two groups: REHAB+SHAM and REHAB+STIM. Both groups will do special exercises to help with walking and balance. The difference is that the REHAB+STIM group will also receive real electrical stimulation called transcranial Direct Current Stimulation (tDCS) and trans-spinal Direct Current Stimulation (tsDCS), while the REHAB+SHAM group will get a fake stimulation called SHAM, which feels like the real thing but does not actually stimulate the brain.

**Key Points**:

• Participants will be involved for 28 weeks, including breaks and follow-up visits.
• Sessions are held 3 times a week, each lasting about 1 hour.
• Participants will undergo tests like brain scans and blood tests to check improvements and safety.