Researchers have used MRI to show the impact of sending electrical pulses to the vagus nerve in an attempt to correct gastrointestinal problems and provide “more precise treatment” that pharmaceutical therapies and diet have not achieved. Results of the study were published in the October issue of Neurogastroenterology and Motility.
“The MRI protocol employed in this study is expected to enable advanced preclinical studies to understand stomach pathophysiology and its therapeutics,” wrote lead author Terry Powley, PhD, professor of neuroscience at Purdue University in West Lafayette, Indiana, and colleagues. “Results from this study suggest an electroceutical treatment approach for gastric emptying disorders using cervical vagus nerve stimulation to control the degree of pyloric sphincter relaxation.”
With the help of MRI, the researchers sought to stimulate the vagus nerve in a rat cohort to better understand how quickly the stomach empties food into the small intestine for the absorption of nutrients. Slow gastric emptying, the researchers said, could indicate gastroparesis, where the stomach muscles do not move properly.
"MRIs are non-invasive, show tissue contrast well and make it easier to repeat an experiment for verification," said co-author Kun-Han "Tom" Lu, a PhD student in electrical and computer engineering, in a prepared statement issued by the university.
The researchers stimulated the vagus nerve using electrical pulses to manipulate the rats’ pyloric sphincter—controlling food exiting the stomach to enter the small intestine. They built 3D versions of the MRI images over time and found stimulation of the vagus nerve relaxed the pyloric sphincter, thereby quickening gastric emptying and eventually correcting gastroparesis.
The researchers seek to further employ the technology to learn more about gastric physiology and will continue to conduct more research to test different treatments on gastric disorders.
"Eventually, by asking a patient to undergo multiple MRI scans with different electrical stimulation settings, we could figure out the best stimulation setting for alleviating that particular patient's symptoms," Lu said.