The main objective of the study is to evaluate the efficacy of 10 sessions of transcranial direct current stimulation of the primary motor cortex to reduce levodopa-induced dyskinesia

Inclusion Criteria:

• patients with diagnosis of idiopathic Parkinson's disease according to Movement Disorder Society (MDS) criteria and levodopa-induced dyskinesia;
• age between 30 and 80 years;
• ongoing therapy with levodopa;
• fulfillment of requirements for the application of transcranial magnetic stimulation (TMS), assessed by completion of the TMS screening questionnaire.

Exclusion Criteria:

• patients unable to give informed consent;
• cognitive impairment (MMSE ≤ 24);
• history of epilepsy;
• pregnant women.