Study finds one-time injection of nerve block may provide relief for some menopause symptoms. (Tyler Olson/SIMPLEFOTO)
Hot Flashes
Relieving troublesome menopause symptoms without hormones

THE QUESTION Women beset by the hot flashes and night sweats so common in menopause often seek treatment other than hormone therapy. Might a procedure that involves injecting a local anesthetic near a bundle of nerves in the neck be a viable option?

THIS STUDY included 40 post-menopausal women, most in their early 50s, who experienced hot flashes and night sweats 10 times a day, on average, with most labeled as moderate to severe. The women were randomly assigned to have the anesthetic bupivacaine injected once in their neck, a technique called a stellate ganglion blockade, or to get an injection of saline. After six months, the number of moderate to severe hot flashes and night sweats fell by an average of 52 percent in women who had the nerve block, compared with a 4 percent drop among those given the saline injection. Symptoms also declined in intensity, falling 38 percent with the true treatment vs. 8 percent for the placebo.

WHO MAY BE AFFECTED? Women experiencing hot flashes and night sweats brought on by menopause, whether natural or induced by hysterectomy or ovary damage from chemotherapy or radiation treatment for cancer. Hormone therapy has proved to be an effective treatment for such symptoms, but studies have found that it carries an increased risk for heart disease. Non-hormonal options include some antidepressants and off-label use of certain anti-seizure and blood pressure drugs, though they may have undesirable side effects; black cohosh, phytoestrogens and ginseng and other botanical treatments, though most of those have not shown much effectiveness in studies; and lifestyle approaches such as dressing in layers, avoiding spicy foods, not smoking and practicing yoga or other stress-reducing or relaxation techniques, though these approaches usually ease only mild symptoms.

CAVEATS Although some data came from skin monitors the women wore for two 24-hour periods during the six-month study period, most of the data came from daily records kept by the participants. The study did not determine whether the positive effect persisted after the study concluded. It also involved only a small number of women. The type of nerve block used in the study is most often used to relieve pain caused by nerve injuries, shingles or angina that has not responded to treatment; the researchers did not determine why or how it works for the menopause symptoms, though they noted that interrupting the nerve pathway might affect blood flow to areas of the brain involved in regulating body temperature.

FIND THIS STUDY Feb. 5 online issue of Menopause.

LEARN MORE ABOUT hot flashes at and (search for “menopause symptoms”).

The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.