eighty patients within age group 18-65 years old with post mastectomy neuropathic pain that are resistant to medical treatment in the form of tramadol hydrochloride 100 mg twice daily, pregabalin 75 mg twice daily and Amitriptyline 25 mg once daily for at least two months or associated with significant adverse effect from medication will be involved in this study.~twenty patients will be randomly allocated into one of the study designed groups using serially numbered opaque closed envelopes. Each patient will be placed in the appropriate group after opening the corresponding sealed envelope. The patient will receive one of the following interventions either:~active tDCS (2 mA) targeting the primary motor cortex of the contralateral side of the pain for 20 minute duration for five sessions in five consecutive days (one session /day),~sham tDCS over the primary motor cortex in the same stimulation parameters will be used but the device will be turned off without patient knowledge after 30 seconds ,~active tDCS (2mA) targeting the insula of the contralateral side of the pain for 20 minute duration for five sessions in five consecutive days (one session /day),~sham tDCS over the insula in the same stimulation parameters will be used but the device will be turned off without patient knowledge after 30 seconds.
This study is designed to evaluate the effect of two concentric electrode transcranial direct current stimulation over the primary motor cortex versus insular cortical targets in post mastectomy neuropathic pain.