the role of transcranial magnetic stimulation over the primary motor cortex area on acute postoperative pain after breast cancer surgery and on the probability of developing chronic neuropathic pain.

New analgesic strategies are needed that can be used adjunctively to existing strategies with the potential to reduce reliance on opioid analgesia. Several novel brain stimulation technologies including transcranial direct current stimulation (tDCS) are beginning to demonstrate promise as treatments for a variety of pain conditions. Electricity has no metabolite or other residue, and can be delivered with minimal discomfort and without problems associated with drug-drug interactions.Transcranial direct current stimulation has been studied in patients with various disorders and multiple pain syndromes. There is also evidence that tDCS might be useful in postsurgical pain reduction.

Inclusion Criteria:

• ASA I-II, scheduled for unilateral modified radical mastectomy with axillary dissection for breast cancer

Exclusion Criteria:

• patients with intracranial metallic devices or with pacemakers or any other device.
• patients with Neurological or psychiatric disorders,
• patients taking major centrally acting drugs (antiepileptics or antidepressants), -opioid dependence,
• substance abuse,
• severe cardiopulmonary, renal, hepatic diseases, and
• those with extensive myocardial ischemia or unstable angina.