Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease. It is a progressive and disabling disease with significative impact on quality of life. Since it has no cure, available treatment is targeted to improve the symptoms due to a lack of dopamine in the central nervous system. The aim of the study was to see how transcranial photobiomodulation (tPBM) helped patients with Parkinson's disease.

Inclusion Criteria:

• idiopathic PD,
• Hoehn & Yahr stage I-IV,
• independent gait with or without technical assistance
• stable parkinsonian medication for at least a month before the study star.

Exclusion Criteria:

• comorbidities that affect balance or walking,
• other neurological pathologies besides PD,
• chronic diseases not medically controlled and participation in another physiotherapy program or sport activity during the intervention period or in the month before starting the study