Access to the PPM Journal and newsletters is FREE for clinicians.

New Neuro-Stim Device Lessened Abdominal Pain in Adolescents

October 4, 2017
Electrical nerve stimulation introduces a potential non-pharmacologic treatment to address pain in adolescent patients who present with functional gastrointestinal pain disorders.

With Adrian Miranda, MD, and Gary W. Jay, MD

Administering percutaneous electrical nerve field stimulation (PENFS) with Neuro-Stim, a FDA-cleared device manufactured by Innovative Health Solutions, in an adolescent population whose primary complaint was gastrointestinal pain, appeared to lessen subjective pain scores, according to findings published in The Lancet Gastroenterology and Hepatology.1

The researchers were able to demonstrate that abdominal pain—the primary efficacy outcome of a difference from baseline to treatment—improved significantly in patients who underwent PENFS applied to the ear, as compared to those who had the sham treatment.1  The PENFS device must be applied by a licensed clinician.

Nerve stimulation device lessens gastrointestinal pain in teens.

Efficacy Achieved Using Neuro-Stim for Gastrointestinal  Pain 

A randomized clinical trial  in which 115 pediatric patients, ranging in age from 11-18 years old, who presented with abdominal pain related to a functional gastrointestinal (GI) disorder were treated at a single, out-patient clinic in the midwest.1

“We had heard about similar [favorable] results in other chronic pain conditions, but most results were from anecdotal reports,” said senior author Adrian Miranda, MD, a pediatric gastroenterologist and associate professor at the Medical College of Wisconsin in Milwaukee, “We had to carry out a randomized controlled trial to properly assess the findings,” for GI pain.

More importantly, our preclinical studies demonstrated a reduction in the firing of neurons in the amygdala and spinal cord using the same technology,2 Dr. Miranda told Practical Pain Management, “These central areas have been proposed by many to play a critical role in the development and maintenance of chronic pain.”

Functional abdominal pain disorders are a group of conditions, such as irritable bowel syndrome, abdominal migraine, and functional abdominal pain syndrome, in which pain is typically the most prominent complaint and symptoms are not caused by other conditions.

Study Design and Methodology 

Patients were enrolled in the trial between June 2015 and November 2016. Researchers administered the non-invasive PENFS procedure via the external ear (n = 60) or a sham with no electrical stimulation (n = 55) for four weeks. The procedure was initiated with the intent to modulate central pain pathways. Patients were randomized equally to each arm with stratification based on sex, and presence or absence of nausea. Patients, caregivers, and researchers were blinded to allocation by group.

An outcomes analysis included 57 patients in the PENFS arm and 47 patients in the sham group after patients were excluded for discontinuation of treatment or for having organic disease.1

The primary efficacy endpoint—change in baseline reported abdominal pain—was assessed with the Pain Frequency Severity Duration Scale (PFSD), a subjective tool used to derive a quantifiable pain score in these young participants.1 The researchers used PFSD scores to assess improvements from the worst abdominal pain score as well as from a composite abdominal pain score.

Reduced GI Pain Was Sustained Following Neurostimulation 

After three weeks of treatment, patients in the PENFS arm experienced a greater decrease in worst pain compared with patients in the sham arm (median score PENFS 5.0, IQR 4.0 - 7.0; sham 7.0, 5.0 - 9.0). The least-square means estimate of change in worst pain was 2.15 (95% CI: 1.37 - 2.93, P < .0001).1

Median composite scores of PFSD also decreased significantly in the PENFS arm, from 24.5 (IQR 16.8-33.3) to 8.4 (3.2-16.2), compared to the sham arm, which went from 22.8 (8.4-38.2) to 15.2 (4.4-36.8).1

Both worst pain and composite pain effects were reported for a median of 9.2 weeks during follow-up.1 The median worst pain was 2.0 points lower at follow-up in the PENFS arm but only 0.5 points lower in the sham arm (P < .0001). In addition, median composite pain at follow-up was 12.5 points lower in the PENFS arm compared to 6.0 points lower in the sham arm (P=.018).

“I know that ultra-high frequency can cause specific neurochemical changes that decrease pain,” said Dr. Gary W. Jay, MD, a clinical professor in the Headache Division in the Department of Neurology at the University of North Carolina, Chapel Hill.

“While I can at least get some idea as to why the reported pain decreased from this study, we don’t know what the parameters of electronic stimulation were, and they’ve done no testing other than filling out subjective forms,” Dr. Jay told Practical Pain Management.

Need for Further Understanding of Longterm Benefits

Dr. Miranda shared some additional information on how persistent this therapy might be at reducing abdominal pain.

“I have patients whose symptoms have resolved and are six months out of treatment while others have recurrence at five months,” he said, ”and it may be that a second treatment is needed for those who have recurrence, or perhaps a longer initial trial of six weeks would be required to prevent relapse.”

“It’s too early to tell, and certainly longitudinal studies need to be done,” Dr. Miranda said, “Perhaps in the future, this therapy can be combined with imaging techniques to better predict the phenotype that will respond to treatment.”

Dr. Jay concurred with the need for imaging studies, particularly as PFSD is susceptible to issues surrounding subjective measurements. Objective, physiological measurements could yield meaningful insights into the biological basis of the results achieved in this study, according to Dr. Jay. He also noted that the study did not provide sufficient detail about the methodology used to employ electrical stimulation.

“The researchers are not giving us any parameters of what they are doing, and they are also not looking at whether there are any physiological changes occurring,” said Dr. Jay. “You would want to do functional MRIs to see exactly what is this stimulation is doing.”

Conclusions and Future Directions

Dr. Miranda expects transcranial electrical stimulation to hold promise for additional pain disorders.

“I think we have just started to uncover the possibilities of neuromodulation, using peripheral electrical stimulation. The implications for this type of non-invasive neuromodulatory therapy holds promise  beyond just functional pain disorders, in my opinion,” said Dr. Miranda, “and if you think about the central mechanisms that are involved in chronic pain, there is really no reason why this technology couldn’t be applied to many pain disorders.”

Dr. Jay agreed that neuromodulatory electrical stimulation has the potential to improve other disorders characterized by pain.

“Given that some of the animal studies show amygdala or limbic system involvement secondary to the stimulation, which would make sense in certain disorders, I would want to see trials that at this aspect. The limbic system is very highly incorporated into another so-called functional pain syndrome, fibromyalgia,” he told Practical Pain Management.

Dr. Miranda explained the need for creating distinct therapeutic regimens for individual patients and emphasized the importance of understanding which components could form the foundation for such a regimen, including pharmacotherapy, physical reconditioning, and neuromodulation.

“We need to figure out who our responders are for each treatment and tailor our approach for each patient.  There is not one treatment that will work for all patients,” said Dr. Miranda. “Yet we don’t always discuss these components of treatment with our patients because of time constraints, lack of resources, or issues with insurance coverage,” Dr. Miranda said.

The American Neurogastroenterology and Motility Society funded this research. The authors have no other disclosures.

Last updated on: October 12, 2017
Continue Reading:
The Slipping Rib Syndrome: An Overlooked Cause of Abdominal Pain

Join The Conversation

Register or Log-in to Join the Conversation
close X