Effect of Repetitive Transcranial Magnetic Stimulation on Malignant Visceral Pain

Abstract

Background and objectives. To assess the efficacy of 10 sessions (once daily for 10 days) of repetitive transcranial magnetic stimulation (rTMS) on primary motor cortex (M1) in patients suffering from malignant visceral pain. Materials and methods. Thirty four patients were included in the study. They were divided randomly into two groups (17 patients for each, using closed envelopes): real rTMS (20 Hz, 10 trains with intertrain interval of 30 s with total pulses 2,000, intensity 80% of motor threshold) and sham rTMS (coil elevated and angled away from the head). Stimulation was applied over M1 every day for ten consecutive days. Patients were evaluated using a verbal descriptor scale (VDS), visual analog scale (VAS), and Hamilton rating scale for depression (HAM-D) at baseline; after the 1st, 5th, and 10th sessions; and then at 15 days and one month later after the end of the treatment sessions. Serum human dynorphin (Dyn) was measured at baseline, and after the 5th and 10th sessions. Results. Fifteen patients from each group completed the study. There was no significant difference between real and sham groups in the duration of illness, or any rating scales at baseline. Compared with the sham group, the VAS/VDS scores decreased more in patients who received real rTMS over the course of the treatment and at 15 days follow-up than in those who received sham stimulation. Scores were the same at one month follow-up. There were no significant changes in serum human Dyn in either group. Conclusion. The results confirm that 10 sessions of rTMS over the M1 can induce pain relief in malignant visceral pain for at least 15 days but the effect is not maintained at one month.

Bicentre, randomized, parallel-arm, sham-controlled trial of transcranial direct-current stimulation (tDCS) in the treatment of palliative care patients with refractory cancer pain

“…The origin of pain does not appear to affect the result. The main results concern visceral pain [17,18], but one of our patients with pain related to vertebral metastases was also considerably improved [15]. In this palliative care setting, in which patients are often difficult to mobilize, tDCS is much easier to deliver than rTMS, as it can be performed at the patient's bedside and possibly at home.…”

“…The calculation of the number of patients could not be based on similar protocols. Those dedicated to cancer pain [17,18] were aimed more at non-hospitalized patients with a priori a life span of more than 3 months. The only protocols performed in palliative care involved ketamine infusion treatments.…”

“…Finally, two recent studies have confirmed the efficacy of NIBS in the treatment of cancer pain. Both of these studies concerned patients with visceral pain, as in two of our cases, but these patients were generally not at the end of life [17,18]. In the study by Khedr,17 patients were treated by 10 rTMS sessions targeted to the motor cortex and another 17 patients were treated by 10 sham rTMS sessions.…”

“…Both of these studies concerned patients with visceral pain, as in two of our cases, but these patients were generally not at the end of life [17,18]. In the study by Khedr,17 patients were treated by 10 rTMS sessions targeted to the motor cortex and another 17 patients were treated by 10 sham rTMS sessions. These patients experienced visceral pain related to cancer progression, mainly involving the liver or pancreas.…”

“…All patients experienced visceral pain related to progression of liver cancer. The rating scales were the same as those used in Khedr et al study [17]. Actively stimulated patients were improved by the 5th session and remained improved for an average of 1 month.…”