July 15, 2019Women's Health
Endometriosis occurs when the uterine tissue lining grows outside of the uterus and is estimated to affect up to 176 million women worldwide. It is an inflammatory condition that can lead to infertility and cause chronic pain. The usual gynecologic treatments include hormonal therapy and surgery to remove the growths. However, in many cases, pain returns after the interventions.
Pelvic pain associated with endometriosis often becomes chronic and can persist (or recur) following surgical and hormonal interventions. According to results published in Regional Anesthesia & Pain Medicine (11 July 2019), treating pelvic floor muscle spasm with botulinum toxin may relieve pain and improve quality of life.
Botulinum toxins, such as Botox, work by blocking the nerve signals for muscles to contract and have been used to treat migraines and certain movement disorders. Previous research has suggested that botulinum toxin may help women experiencing other types of chronic pelvic pain, but this treatment had not been studied in women with endometriosis.
For the study, women with surgically treated endometriosis who were generally taking hormones to suppress menses, but who continued to experience pain and had pelvic floor muscle spasm, initially received injections of botulinum toxin or saline as part of a placebo-controlled clinical trial, targeting areas of spasm. At least one month after the masked study injection, 13 participants chose to receive open-label botulinum toxin injections in areas that remained in spasm and were then followed for at least four months.
Results showed that in all participants during follow-up, pelvic floor muscle spasm was not detected or occurred in fewer muscles. Within two months of receiving the injections, pain decreased in all of the participants, with 11 out of 13 subjects reporting that their pain was mild or had disappeared. Additionally, usage of pain medication was reduced in more than half of the participants. Prior to receiving toxin injections, eight participants reported moderate or severe disability and after treatment, six of those patients noted an improvement. The study participants also experienced a decrease in muscle spasm and had pain relief that resulted in less disability and less use of pain medication. These findings suggest that pelvic floor muscle spasm may be experienced by women with endometriosis and contribute to pain persisting after standard treatment. Importantly, the beneficial effects were long-lasting, with many patients reporting pain relief lasting at least six months.
According to the authors, larger clinical studies will need to confirm the current findings. In addition, future research will focus on the mechanisms underlying chronic pelvic pain and better understanding of ways in which botulinum toxin may help treat those disorders.