Ear Stimulation Eases IBS Pain in Teens

— 59% of users versus 26% of those given sham stimulation experienced a reduction in worst pain

by Diana Swift, Contributing Writer August 14, 2020

A noninvasive device (IB-Stim) delivering percutaneous electrical nerve field stimulation to the external ear safely reduced abdominal pain and improved quality of life in adolescents with irritable bowel syndrome (IBS), data from a prospective double-blind study indicated.

Confirming efficacy for improving abdominal pain in functional gastrointestinal disorders observed in an earlier study, the current IBS-focused analysis of trial data found that the percutaneous electrical nerve field stimulation (PENFS) device, worn behind the ear, led to reductions of 30% or more in worst abdominal pain in 59% of young patients compared with 26% of patients who received sham stimulation (P=0.024), reported Katja Kovacic, MD, of the division of pediatric gastroenterology, hepatology and nutrition at Medical College of Wisconsin in Milwaukee, and colleagues.

PENFS recipients had a composite pain median score of 7.5 (interquartile range [IQR] 3.6-14.4) versus 14.4 for the sham group (IQR 4.5-39.2; P=0.026) and a usual pain median score of 3.0 (IQR 3.0-5.0) versus 5.0 in the sham group (IQR 3.0-7.0; P=0.029), they noted in Clinical Gastroenterology and Hepatology.

Furthermore, a symptom response scale score of 2 or more was observed in 82% of patients receiving PENFS versus 26% of sham stimulation recipients (P≤0.001), and no significant side effects were reported.

“This study confirms that auricular neurostimulation via PENFS significantly improves abdominal pain and global symptoms in affected adolescents,” wrote Kovacic and colleagues.

They noted that the results from this first prospective trial of PENFS in IBS are clinically relevant in light of the poor efficacy of pharmacological therapies for children with functional abdominal pain disorders and the dearth of safer treatment options. They argued that the device, recently approved by the FDA for IBS pain in children ages 11 to 18, should also be considered for use in adults, noting that peripheral neurostimulation has gained attention for its noninvasive modulation of central pain pathways via stimulation of peripheral cranial neurovascular bundles in the external ear.

Gastroenterologist William Chey, MD, of the University of Michigan at Ann Arbor, called neurostimulation an exciting new treatment modality for patients with functional gastrointestinal disorders.

“We’ve been engaging in neuromodulation for many years using drugs like tricyclics, selective serotonin reuptake inhibitors, and selective norepinephrine reuptake inhibitors, as well as via behavioral techniques like cognitive behavioral therapy and self-directed hypnosis,” he told MedPage Today. “Thus, the concept of neuromodulation is not new and, indeed, has already been validated using these medications and psychological therapies.”

“We also know that neurostimulation works for a number of somatic pain disorders,” said Chey, who was not involved in the study.

In his view, the study adds “persuasive evidence” to a growing body of literature supporting a role of neurostimulation for the treatment of visceral pain. “I agree with the authors that studies in adults with painful conditions like IBS are warranted,” he added, noting that his colleague Jiande Chen, PhD, had recently obtained funding from the National Institutes of Health for such testing. “We will be starting a series of studies to better understand the benefits of neurostimulation as a treatment for pain and other symptoms in adults with IBS.”

For his part, pediatric gastroenterologist Marc Rhoads, MD, of McGovern Medical School at UTHealth in Houston, who was not involved in the research, noted that IBS and other chronic abdominal pain disorders affect about 10% of all children older than age 5, “so this is an important issue. If the cost of the device was less than $1,000, many middle-to-upper-class families would gladly pay for it, because the pain can become dominant and disabling. I doubt that insurance would pay for it.”

Study Details

Data were extracted from a prospective study of 115 largely Caucasian adolescents recruited from a tertiary care pediatric gastroenterology clinic from June 2015 to November 2016.

The mean age in the PENFS arm (n=27) and the sham arm (n=23) was just over 15 years; 89% and 91%, respectively, were female. Mixed-type IBS subtype predominated in the intervention group (63%), while IBS-constipation was the most common subtype in the sham group (43%). The primary endpoint was the number of patients with >30% decrease in worst abdominal pain severity after 3 weeks of therapy.

The number needed to treat for one patient to reach the primary endpoint was three. At the extended follow-up 8 to 12 weeks after end of therapy, 32% of the treatment group continued to have improvement of at least 30% from baseline in worst pain compared with 18% of the sham group, but this difference was not significant (P=0.33).

According to the authors, future studies should focus on characterizing short- and long-term responses to PENFS in different IBS subtypes and other functional gastrointestinal disorders, identifying the optimal duration of therapy and also assessing changes in stool patterns. In addition, mechanistic studies are needed to help target this therapy to the most appropriate patient population, including adults.

Among the study’s limitations, the investigators noted the relatively small sample size in the subanalysis and a design not intended to evaluate long-term efficacy. Another limitation was the incomplete assessment of stool frequency and consistency as prespecified outcomes in accordance with FDA and European Medicines Agency recommendations.

Furthermore, although stimulation parameters were below sensation threshold, some patients may still have been able to perceive the stimulation. Additionally, the findings may not be generalizable to less complex IBS patients than those in the study cohort.