Conference Coverage

Endometriosis pain stemming from pelvic spasms improved with botulinum toxin


Key clinical point: Repeated onabotulinumtoxinA injections to treat pelvic spasms in women with chronic pelvic pain related to endometriosis relieved pain in most women.

Major finding: A month after the open-label injection, spasm was reduced or absent in all subjects (P = .0005), with 11 of 13 rating pain as absent or mild (P = .0001).

Study details: An open-label extension in 13 of 28 patients enrolled in a randomized trial.

Disclosures: Dr. Karp and her colleagues’ research is supported by the NINDS and the Eunice Kennedy Shriver National Institute of Child Health and Human Development. OnabotulinumtoxinA for the clinical trial is supplied by Allergan. Dr. Karp has received research support from Allergan and Merz.

Source: Karp B et al. AAN 2018, Abstract P2.096; Karp B et al. AAN 2018, Abstract P2.098.



– Women treated surgically and with hormones for endometriosis may continue to experience pain, say investigators, and that pain frequently extends beyond the pelvis.

At the annual meeting of the American Academy of Neurology, Barbara Karp, MD, of the National Institute of Neurological Disorders and Stroke, presented results from an ongoing randomized trial of women with endometriosis receiving botulinum toxin to treat endometriosis-related chronic pelvic pain and pelvic spasm.

endometriosis designer491/Thinkstock
“When we saw the women with endometriosis we realized there was more going on, and that they were very broadly sensitized to pain,” Dr. Karp said in an interview. “So we started looking at that systematically.”

All 28 women currently enrolled in the trial (median age, 29 years) were evaluated by a gynecologist to confirm pelvic muscle spasm as their primary source of pain. Each also underwent a neuromuscular examination to identify pain points beyond the pelvis.


All subjects had myofascial dysfunction. Most reported headaches and half reported orofacial pain, while 13 subjects reported myofascial trigger points in all the 26 spots assessed, which included head and facial muscles, shoulder and back muscles, and muscles in the buttocks, abdomen, and upper legs.

Dr. Karp said her group hypothesized that for patients with endometriosis, the widespread pain seen in the study “probably has some origin in sensitization initiated by pain associated with the endometriosis lesions, and that gives us a mechanism to think about peripheral and central sensitization.” But she noted that such sensitization can be easily missed in the clinic.

“One of the things that’s really underappreciated is how much women with chronic pelvic pain have pain elsewhere. So the neurologist or pain specialist may say, ‘that’s not my body territory, there’s something going on with your pelvis.’ And the gynecologist may be focused on the endometriosis and the endometriosis lesions. So you have these women with really widespread pain problems whose care is being fractionated.”

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