#5 Inventing Functional EDx

James Hedgecock, PhD

1971 UCLA Medical Center

Doctors from the University of Tokyo present a series of lectures at the UCLA Medical Center in 1971. The presentation dealt with the ways acupuncture is utilized in their hospital. They explained how in 1950 Yoshi Nakatani, PhD physiologist, while mapping the skin’s electrical impedance found a correlation between acupuncture points and site of lower electrical impedance. This discovery encouraged them to take acupuncture seriously and pursue more studies.

To determine what if any chemicals were released by needling, they withdraw fluid from the site where needling was to be applied. Then, after needling, withdrew fluid and found two nerve stimulants were released - histamine and bradykinin. Next, an acupuncturist examined pain patients and marked the sites to be treated. Then the acupuncturist was asked what result could be expected. Last, instead of needling, histamine was injected at the points. They found the results matched those expected by the acupuncturist.

One experiment used different types of stimuli. The Japanese doctors found greatest amount of histamine and bradykinin were released using a 10 amp at 27 volts stimulus. In 10 to 15 seconds of transcutaneous electrical stimulation more of these stimulants were released than by 2 hours of needling.

When describing how acupuncture is used in their hospital, I found it odd they didn’t use the transcutaneous method. Instead needles were inserted then attached to electrical stimulation. This was said to release less histamine, but patients demanded the needles insertion, because they had faith in needling. Also the needle/electric method used lower stimulation over a longer time, so it was less painful than the transcutaneous electrical stimulation. However, to me the idea of a painful stimulus for 10 to 15 seconds seems far better than a less painful for 20 minutes or more.

Intrigued, I studied acupuncture under the leading American acupuncturist, Dr. Richard Yennie and became certified by the American Acupuncture Society in 1972. In 1973 I visited acupuncture clinics in Japan, Korea and Hong Kong, where I was again certified by the Hong Kong Acupuncture Federation.

I soon had an acupuncture clinical program going in the University of Pasadena, College of Chiropractic Outpatient Clinic. A stroke patient treated in the clinic had such encouraging results that soon dozens of stroke patients were being treated.

1974-1975 University of Pasadena, California

While treating stroke patients I made an interesting observation. To a non-stroke subject the transcutaneous electrical stimulus feels uncomfortable, but to stroke patients it feels like being jabbed by a burning cigarette. It takes a period of time for the electrical current to breach the skin’s impedance, so in anticipation of the coming pain some patients would breathe normally, while others held their breath. I noticed that for those holding their breath the current breached the skin’s impedance in a few seconds, while for those breathing normally it took several seconds to minutes to breach the skin’s impedance. I reasoned that an oxygen debit somehow reduced the skin’s electrical impedance. From a practical standpoint, having normal breathers hold their breath reduced treatment times. Based on this phenomenon I wrote my PhD thesis explaining the probable neurological pathways and reflexes. I presented my paper to the University of Pasadena Neurology Department and the PhD faculty decided I had discovered a previously unknown phenomenon and after a panel grilled me on my ideas, in short order I was awarded a PhD in neurophysiology.

Acupuncture needling is a bit painful and one can feel exactly where the needle is, so obviously the (Fast Pain) A-delta fibers (group III) are being stimulated. The A-delta fibers are rather fascinating. They are slightly larger than C-Type fibers at 2-5 mm in diameter, thinly myelinated and conduct signals at 5-40 meters per second, which is around the speed of a human runner. Because they have small receptor fields they exactly localize pain. So the idea is that immediately upon traumatizing a nerve root or peripheral nerve, the A-delta fiber allow exactly localization because symptoms seem to the brain to be coming from the peripheral area connected to the A-delta fibers of the injured nerve root or peripheral nerve, which is an extension of the nerve root. An interesting anatomical factor is that A-delta and C-Type fibers have no dendrites. Instead they have an axon coming to the cell body and an axon leaving it. My theory involves the Hering Breuer Reflex. This reflex is what makes suicide by holding ones breath impossible. I believe it kicks in when one holds their breath and the oxygen debit causes centers in the Pons and the dorsal and ventral respiratory centers of the Medulla to induce breathing. It seems that this reflex feeds into the autonomic system exciting electrical activity in peripheral nerves and their endings that lower skin electrical impedance. This is like the reaction one has when taking a polygraph and under the stress of lying there is a shift in skin impedance. The stress here is oxygen debit – I am dying. Many attribute lowering of impedance to increase vasomotor tone with sweat lowers impedance. More likely, it involves both as a single mechanism.

Nerve Fiber Anatomy

Descriptions of voltage-gated channels can be confusing, but the basic structure of nerve fibers is simple, as is the function. Function is singular - producing nerve signals. As for structure, the best analogy is that of a long hollow straw cut into units lined up like railroad cars inside a larger tube made of fat (see above illustration). Each unit is a voltage-gated channel (VGC), which combined with other units send nerve signals traveling along the fiber. The surrounding fat insulates the VGC to keep the electricity inside the fat tube, which is like the cover of an electric cable that prevents being shocked when handling the cable, such as plugging it into an electric outlet. Some types of fibers trigger signals when mechanically distorted. Others send signals (action potentials) when chemically stimulated, such as at the connection between nerves ending, the synapse. When sufficient voltage is applied to the A-delta fibers the voltage-gated channel opens and there is an ion shift, and like a tinny generator puts out a burst of microvoltage that triggers the next voltage-gated channel and the next, so on down the line. This is called an action potential. The definition of potential is voltage; therefore, an action potential is literally a series of voltage bursts traveling along the nerve fiber – voltage in action.

Back to the mid 1990s

Like 99.9% of all non-neurologists, I was under the impression that standard electrodiagnostic tests assessed function of all types of nerves. Reading neurology pamphlets leaves the impression that function and pain are assessed. Actually the phrasing is such that the truth is there, but the implication is that pain and function are diagnosed. For example, on the university of Pittsburg Neurology Department’s webpage the following paragraph appears:

A technician or physician electrically stimulates a nerve from the skin surface causing it to fire resulting in either a muscle contraction or sensory impulse that is recorded by electrodes. Nerve conductions measure the speed and efficiency of nerve transmission. The stimulation is mildly painful but well-tolerated by the vast majority of patients.

The first section underlined, to be accurate, should read: Nerve conductions measure the speed of conduction which helps estimate the presence of gross structural damage. The phrase, measures the speed and efficiency of nerve transmission leaves the impression of assessing function. The reader certainly has no hint that nerve conduction speed is a method for estimating a nerve’s gross structural integrity. The second: The stimulation is mildly painful but well-tolerated by the vast majority of patients. This is a total lie, because the vast majority of patients say they will never submit to another nerve conduction test.

An electromyography paragraph states: For this part, a physician inserts a thin needle electrode into muscles and records their activity at rest and with contraction. The patterns seen can identify the presence of muscle disease or the results of nerve dysfunction. The needle examination is a little painful at times, but again, most patients tolerate it easily. The needle portion lasts 10-30 minutes depending on the problem, and nerve conductions take 20-40 minutes to perform.

The section, records their activity at rest and with contraction leaves the impression that the recording is deciding factor. Any honest EMG neurologist will attest to the fact that the judgment of the sound of the muscles electrical activity is the deciding factor, as is the judgment of the oscilloscope waveform. Therefore, instead of being based on objective data, EMG is subjective.

In the next underlined section, can identify is obviously ambiguous. Does this mean detection is one in a million or 99 in 100? These are deceptively clever lie. The proof that such phraseology is misleading is found in the fact that 99% of non-neurologists believe 1918-1944 EMG-type EDx can assess function of motor and pain fibers.

Before I realized the stunning limitations of EMG-type EDx, for over two decades after my PhD, I worked with hundreds of radiculopathy patients. In the 1990s I began wondering why, after a 1963 Nobel Prize had been awarded for discovering the voltage-gated channels, had no one developed a way to measure nerve function. In a time prior to Google and Wikipedia, I began spending many hours at the University of California Irvine’s library on Boolean searches.

Several interesting nerve function studies were found, but initially the most surprising findings was that of a device market since the early 1980s. This device was purported to measure pain fiber function using current output correlated with the patient reporting the threshold sensation. I called the manufacture and received a list of three local neurologists using the device. When I called, each initially said they like the device. However, after questions concerning repeatability all three admitted their device was in storage and no longer in use. The reason given for first saying they liked the device was that they were embarrassed to have been duped into buying it.

This current input device has a mechanism that helps stabilize the current output by shifting the voltage. It does this without recording the voltage. Therefore, the device is measuring a part of the electrical signal having no effect on triggering the voltage-gated channels, while ignoring the voltage that does trigger action potentials. The manufacturer claimed in a 1970s patent application that this mechanism is their exclusive invention. However, the mechanism had been reported in the literature in a 1956 study, which the manufacturer included in their patent application. In other words, they had lied to the patent office. The manufacturer also claimed their device was the first and only device use 150 Hz stimulation. Again, in a journal given to the patent office, appears a full-page ad for a device, which was on the market since the 1930s, capable of frequency settings from 0 to 10,000 Hz., so 150 Hz. is not limited to their device. Additionally, the advertised device could be set on several waveforms, including sine wave, which the manufacturer claimed was another exclusive feature of their device. The fact is that this bogus device is likely the reason Gieco and State Farm tried to kill the F-NCS. They likely thought my device was a repeat of the worthless current output device.

The search came up with helpful information, such as nerve fibers responding to certain frequency ranges. Researchers had found A-beta fiber (light touch) respond best to frequencies between 1000 Hz to 4000 Hz, C-Type fibers respond best in a range from 1 Hz to 10 Hz and A-delta fibers between 150 Hz and 350 Hz. Attempts had been made to assess pain fiber function by measuring the strength of electric current causing threshold action potentials, but three factors were consistently overlooked.

1. Prior to the discovery of the voltage-gated channels researchers measured current output, which is the volume of electrical energy, which has no effect on VGC. Once it was known that voltage is the key to triggering VGC, a few studies measured the voltage, which is where error (b) comes into play.
   

2. As I have explained, since the 1920s shifting skin impedance has been one of the measurements in the polygraph (Lie Detector) test. The main point is that the skin’s electrical impedance shifts and not fixed.
   

3. The next factor isn’t quite so obvious. The skin impedance is usually greater than the nerve’s action potential threshold and motor units activation threshold.

It all boils down to a single factor that prevented accurate functional measurement - Turning stimulus off between serial measurements. Each time the stimulus is turned from zero and up until the patient reports the threshold sensation, researchers thought this was the nerve’s threshold, while it was the skin’s impedance threshold. Because impedance shifts, this was attributed as well to the nerves.

Functional Measurement Device

With input from colleagues a device was designed and built, and I set about seeing if I could detect pathology.