Repetitive transcranial magnetic stimulation (rTMS), a non-invasive brain stimulation technique, may be a viable therapy for women with endometriosis experiencing chronic pelvic pain for whom other treatments have failed, a study suggests.
The study, “Repetitive Transcranial Magnetic Stimulation Therapy (rTMS) for Endometriosis Patients with Refractory Pelvic Chronic Pain: A Pilot Study,” was published in the Journal of Clinical Medicine.
Endometriosis is a chronic inflammatory disease caused by the abnormal growth of womb cells outside the uterus. It is estimated to affect approximately 10% of all women of reproductive age and is usually associated with chronic pelvic pain, among other debilitating symptoms.
“Even with combined therapeutic approaches not all patients experience pain relief, for many of whom chronic intractable pain is a major problem despite repeated surgery. This condition is frequently associated with medication overuse, impairment of quality of life and depression,” the researchers said.
Previous studies have shown that rTMS — a non-invasive technique in which nerve cells in the brain are stimulated with magnetic pulses — performed over the brain’s motor cortex (the region responsible for the control of voluntary movements, called M1) effectively led to pain relief for some types of pain.
However, the effectiveness of rTMS on controlling chronic pelvic pain associated with endometriosis had never been addressed.
A team of French researchers set out to assess the therapeutic potential of rTMS in providing pain relief, and improving the quality of life, of women with endometriosis experiencing chronic pelvic pain.
The pilot, open-label, prospective trial (NCT03204682) enrolled a total of 12 women with endometriosis who completed five sessions (one per day) of rTMS delivered to M1 (1,500 pulses at 10 Hz) for five consecutive days. Treatment tolerability, changes in perceived pain, and patients’ quality of life were examined up to four weeks after treatment, with a primary endpoint assessment at day eight.
rTMS was generally well-tolerated by the women. However, 50% of the patients reported experiencing light headaches, and 25% experienced asthenia (overall weakness and fatigue). No serious adverse events or pain aggravation were reported by any of the participants.
In total, nine out of the 12 women initially enrolled in the study reported improvements on perceived pain, measured by the Patient Global Impression of Change (PGIC) scale.
According to data from the Brief Pain Inventory, rTMS led to a significant decrease in pain intensity (5.1 vs 4.1) from day one to day eight, and in the overall impact of pain in patients’ quality of life (6.2 vs 4.2). These improvements in pain intensity and interference remained present until four weeks after treatment.
“This prospective pilot study showed that high frequency motor rTMS is feasible and well-tolerated in patients with refractory chronic pelvic pain due to endometriosis,” the researchers said.
“This study paves the way for a future study of analgesic efficacy using a double-blind trial and presents initial promising support for a new analgesic technique for use in daily clinical practice in patients for whom all other treatments have failed. Although non-invasive and well-tolerated, a confirmatory study using a double-blind design is mandatory before developing such treatment in daily practice,” they added.