|
Permission is granted by the author for anyone to copy and distribute this document to any other party so long as the author's name and the copyright notice is retained on all copies or sections of the document.
Biofeedback, Electro-acupuncture, and the Gastrointestinal Tract
© William Alford 1999
It has long been known that the gastrointestinal tract (GIT) is exquisitely sensitive to activity of the central nervous system (CNS). In the early 19th century, Beaumont published observations that emotions could delay gastric emptying and produce changes in the gastric mucousa. Walter Cannon (1902) demonstrated the relationship between stress and intestinal motility around the turn of the century when he noted changes in the flow of intestinal contents of cats that were confronted by a growling dog. And, of course, everyone is familiar with the work of Pavlov, whose name has become synonymous with conditioned responses. He was the first to show in 1927 that the secretion of digestive juices and contractions of the stomach and intestines can be conditioned to respond to a specific stimulus.
However, this knowledge was not of practical value until the technology was developed that gave scientists the instrumentation to monitor many of the subtle biological signals that reflect internal physiological changes and to “feed back” and display these signals. Once these formerly “unconscious” bodily functions could be observed, it became possible for humans to learn to control what were previously thought to be completely automatic and uncontrollable biological processes. Neal Miller, the father of modern biofeedback, chronicled his experiments that proved that the control of the autonomic nervous system could be learned in his now classic paper, Learning of Visceral and Glandular Responses, in 1969. This work illustrated the difference between the classical conditioning of Pavlov, in which the reinforcement for the learned response must also elicit the response that is sought, and instrumental learning in which a reward can reinforce any biological response that immediately precedes it. He was able to demonstrate definitively that blood pressure independent of heart rate, intestinal contractions, heart rate, kidney function, and even the blood flow in the gastric mucousa could be learned by laboratory animals. In one dramatic experiment he trained a lab rat to increase blood flow to one ear only, turning it pink while the other ear remained white. He outlined the possible role of instrumental learning in maintaining homeostasis in humans and speculated that this type of training could have therapeutic benefit for some aspects of illness: “...there remains the intriguing possibility that, when pathology interferes with innate control, visceral learning is available as a supplementary mechanism.”
After its first flurry of discovery, excitement, and promise in the late sixties, interest in biofeedback then waned for want of appropriate instrumentation, reluctance to embrace it by the established medical world, and an unfortunate association with the culture of the “human potential enhancement” of the times. Now interest has exploded again with the advent of powerful personal computers, new biosensors and electronic instrumentation, and a greater understanding of the workings of biophysiology at the cellular and molecular level.
Technology has also produced its own biophysical challenges to human beings as we now encounter circumstances unknown to our predecessors such as piloting high speed aircraft, the pressures and atmospheres of very deep sea exploration, and the weightlessness of space flight. In particular, space flight has provided very challenging circumstances indeed as it was quickly learned that astronauts experienced dizziness, nausea and vomiting, and discomfort that interfered with their activities and could easily become very dangerous during the rigors of space flight—such as experiencing a vomiting episode while in a spacesuit. As space travel became more frequent, the problem of nausea and discomfort became more apparent with five of the nine Skylab crewmembers complaining of nausea during flights in 1973. In an attempt to learn about the physiological mechanisms underlying nausea and vomiting, NASA established a psychophysiology laboratory at its Ames Research Center near Palo Alto, California under the direction of Dr. Patricia Cowings with the express goal of studying these symptoms and seeking a way to eliminate them.
For over two decades, Dr. Cowngs measured the biopotentials of thousands of volunteers while they were subjected to various nauseogenic stimuli. Her research has let to the development of a unique form of biofeedback that allows the subjects to learn to control the physical responses associated with nausea and vomiting with a very good success rate. The demanding schedules of the astronauts necessitated that any training be done very rapidly and now the established NASA protocol allows healthy subjects to develop this skill in around 6 hours The usefulness of these techniques has been proven by experiments done during space shuttle flights and now astronauts regularly undergo this training at the Ames center before attempting space flight. In 1996, with the current spirit of cooperation between the US and Russian space agencies, Dr. Cowings and her husband and research associate, Dr. William Toscano, transported the necessary NASA laboratory equipment to Moscow to train the cosmonauts as well.
The training done by the astronauts is quite different from conventional biofeedback that usually seeks to return an aberrant biophysical measurement to normal. In this case, the trainees attempt to first arouse and then suppress their measurements in alternating three-minute cycles. The exact mechanism of action is unknown at this time, but this “exercise” of the autonomic nervous system seems to help restore its ability to provide homeostasis. In the case of the astronauts, there is no apparent extinction of the training even several years after its completion.
While the concerns of the astronauts precipitated the research and development of protocols for dealing with these symptoms, the potential for applying the same procedures for more earthbound diseases has not gone unnoticed. Many diseases cause the great discomforts of nausea, vomiting, gastric pain, dizziness, and confusion, and have few treatment alternatives. A few drugs are available for treating nausea and vomiting, but they do not work for everyone and some have troublesome side effects. While exploring treatment options for Chronic Intestinal Pseudo-Obstruction, a degenerative neuromuscular disease of the GI tract, William Alford, the Director of Resources for the Association for Gastrointestinal Motility Disorders, Inc. (AGMD), investigated Dr. Cowings' work and brought it to the attention of medical researchers at the University of Tennessee at Memphis (UTMB) under the direction of Dr. Thomas Abell.
Dr. Abell has investigated and treated GI motility diseases for many years and has published several papers that identify abnormalities in the autonomic nervous system of many of these patients. As a result of this shared interest, a successful collaboration emerged that brought the NASA training protocol to the Autonomic Testing Laboratory in Dr. Abell's motility clinic. Alford succeeded in arranging for his wife, who suffers with the illness to travel to the NASA Ames Research Center in California along with Dr. Hani Rashed from UTMB. Mrs. Alford became the first patient in history to experience the same training as the astronauts in the NASA laboratory.
Dr. Rashed, who heads the Autonomic Laboratory, has very successfully adapted the NASA protocol for use with the Memphis clinic's much simpler laboratory apparatus with very promising results. Some patients have decreased their episodes of severe pain from several events per day to only one or so per week, while others have learned to significantly suppress the symptoms of nausea. One patient has been able to wean herself from a nearly three thousand dollars per month drug regimen to only several hundred dollars per month. Several have unexpectedly reported the disappearance of life-long allergies as the therapy progressed. Dr. Rashed continues to investigate the exciting promise of this non-invasive treatment and it is hoped that funding can be found to duplicate the very sophisticated NASA computerized hardware that would greatly accelerate the effort.
Another marriage between modern electronic technology and very old techniques for dealing with nausea and vomiting involves using electrical stimulation to excite acupuncture points on the human body. The technique of inserting tiny needles into very specific areas of the body for treating various diseases has been known for thousands of years. Only recently, modern science has rigorously investigated this ancient practice and found many of the claims to be sound resulting in the American Medical Association endorsement for the use of acupuncture for treatment of pain in 1999.
There are well known acupuncture sites that have been used to treat nausea, vomiting, bloating, and other gastrointestinal discomforts in the Chinese tradition of medicine. It has also been found that electrically exciting the same points not only produced the same effects but also greatly enhanced them.
Dr. Bob Stern at Penn State is a renowned expert on the gastric rhythms of the stomach and developed many of the techniques to measure these rhythms in a non-invasive manner similar to the EKG of the heart. The electrical signals produced by the muscular contractions of the stomach are amplified and displayed on a graph known as an electrogastrogram, or EGG. Like the scientists at NASA, Dr. Stern also used nauseogenic stimuli and discovered that when the subject experiences nausea, the normal three cycle per minute rhythm of the stomach becomes an erratic pattern known as tachygastria that is two or three times that speed. During tachygastria, the stomach stops working and does not empty. When he examined the same EGG rhythms during the application of traditional acupuncture on the P6 point below the wrist, he observed that the EGG was restored to normal in many subjects and the nausea was abated. Applying an electrical stimulation to the same area greatly enhanced the effect and obviated the need for needles.
Based on similar research with subjects undergoing chemotherapy, Mavin Labs of Citrus Heights, California, developed a small wristwatch-like electrical stimulator that can be worn over the P6 point and apply this stimulation continuously for relief of nausea.
|