Daily repetitive high frequency transcranial magnetic stimulation of primary motor cortex for malignant neuropathic pain

Background: Background: Neuropathic pain in cancer patients can arise as a consequence of cancer- directed therapy, such as surgery, radiotherapy and chemotherapy. Significant analgesic effects of repetitive transcranial magnetic stimulation (rTMS) have been found in several studies of patients with chronic pain of various origins.  Objectives: to assess the efficacy of daily 10 sessions of rTMS on primary motor cortex in patients suffering from malignant neuropathic pain.  Material and methods: Thirty four patients were included in the study. They are divided randomly into 2 groups (17 patients for each) using closed envelop as real rTMS group and sham group. Real rTMS over the hand area of motor cortex (20 Hz, 10 trains with inter train interval 30 second with total pulses 2000, intensity 80% of motor threshold) every day for ten consecutive days (5 days/week) and the coil elevated and angled away from the head as sham stimulation. Patients were evaluated by verbal descriptor scale (VDS), visual analog scale (VAS), Leeds assessment of neuropathic symptoms and signs (LANSS) and Hamilton rating scale for depression (HAM-D) at the baseline, after 1st, 5th, 10th session, 15 day and 1 month after end of sessions.  Results: There was no significant difference between true and sham groups in the duration of illness, VDS, VAS, LANSS scores at the base line. VAS, VDS and LANSS scores of the patients who received real rTMS decreased more over the course of the treatment through the different points of follow-up than those who received sham stimulation but not after one month follow up.  Conclusion: The results confirmed that 10 sessions rTMS over the motor area can induce pain relief in malignant neuropathic pain for at least 15 days but the effect cannot be maintained after one month.