Letters to the Editor: Nerve Fiber Testing, Fibromyalgia
The article by Odell et al in the October issue of Practical Pain Management, Combined Electrochemical Treatment for Peripheral Neuropathy, describes nothing short of a breakthrough for pain management physicians.1
Robert H. Odell, Jr., MD, PhD, and his colleagues have identified the missing link for effective spinal pain treatment. Their work adds a dimension that has been missing from interventional techniques. The physiology of the pain and numbness is made clear, as well as how it can be effected with this protocol.
I am writing to point out an error, however, where it is stated that “nerve conductive velocity (NCV)….can also measure all three [types of sensory nerve] fibers” (A-beta, A-delta and C-Type fibers). NCV cannot test A-delta or C-Type fibers.
Of the three fibers mentioned, NCV only tests large A-beta fibers, which are between 20 to 50 times larger than A-delta and C-Type fibers, respectively. These large fibers, like motor fibers, must lose at least 50% of their myelin before EMG/NCV can detect pathology.
The only electrodiagnostic device that can test small pain fibers is the A-delta (Fast Pain) and C-Type (Slow Pain) fibers device Odell et al used.2 Some might argue that H and F wave can test these small fibers, but this is true only in an extremely limited and crude way.
A 1999 State-Of-The-Art-Review in Physical Medicine & Rehabilitation (1999;13(2):251-252) found that using EMG/NCV, H and F wave “in individuals with predominantly sensory symptoms, it is difficult or impossible to clinically estimate the type of severity of nerve injury.” The review also states: “Only if there is obvious muscle atrophy can one know for certain that (motor) axon degeneration has occurred.”
James Hedgecock, PhD
American Association of Sensory Electrodiagnostic Medicine
Dear Dr. Hedgecock,
Thank you for your timely observations. The sentence is, in fact, inaccurate, as you correctly point out.
To clarify, standard NCV testing does not test A-delta or C-Type fibers. NCV only grossly tests large A-beta fibers, which are several times larger than the other two well-recognized pain fibers, A-delta and C-Type fibers.
An unique electrodiagnostic device that can test small A-delta (Fast) pain fibers is the device that we used. C-Type (Slow Pain) fiber testing is an under-studied and controversial area that is ever further removed from standard NCV discussions.
As you point out, some argue that H and F wave can test these small fibers, but still only the A-beta fibers (or possibly the Ib golgi tendon organ fibers in the H-wave studies, which in addition is only used to evaluate the S1 nerve root reflex loop), are grossly tested, and the afferent and efferent signals of the F wave test passes along motor nerves in both directions, and thus, these studies are not directly relevant to testing any of the pain nerves.
In addition, the “M” in EMG is “myo,” which is “muscle” and is even less directly relevant to A-delta-NCV testing and the objective evaluation of the ECT/CET treatments.
The authors would like to acknowledge and thank James Woessner, MD, PhD, for his assistance in the explanation and clarification of the limitations of EMG/NCV testing on muscles and nerves.
Robert H. Odell Jr., MD, PhD
Richard Sorgnard, PhD
Robert Milne, MD
Peter Carney, MD, FAANS
HCG Dosing For Fibromyalgia
I am a 57-years-old woman who has had severe fibromyalgia, chronic pain, and fatigue since 2000. My current medication regimen has not been helping. I wear a 100 mcg/hr
fentanyl patch for pain management, changing the patch every 48 hours.[Note: prescribing information recommends patches are changed every 72 hours, but physicians commonly prescribe patches for every 48 hours.]
Jacob Teitelbaum, MD, sent me your article on human chorionic gonadotropin (HCG).3 Based on your response to Dr. Teitelbaum’s question, my doctor prescribed
250 mL/d of HCG. I started the intramuscular injections using a 1” 25 gauge needle. However, the injections can be very painful at times. Can a person use the intramuscular mix and inject it subcutaneously?
In addition, on average, how long before I should start feeling a difference? Any information would be must appreciated. Thank you for your work in this area of pain relief!
You are correct when you say I use HCG by the subcutaneous route—the intramuscular and subcutaneous mixtures are not the same.
I use a solution from Anazao Laboratories in Las Vegas. It is 1,000 units per milliliter so the patient only has to inject 0.25 to 0.50 ml subcutaneously per day. We also use it sublingually, but it is not as effective as injections.
I have found the HCG is effective in the first month of use, if it is going to work.
One of the natural functions of HCG is neurogenesis. The use of HCG has been quite compatible with other agents including opi-oids, neuropathic agents, NMDA agonists, and catecholaminergic agents.
In my experience, one of the great benefits of HCG is reduction of opioid use. In fact I now have several patients that use no opioids when several years ago that would have been the primary treatment agent for chronic pain.
HCG is proving to be remarkably safe and a good long-term, maintenance therapy. I do monitor HCG patients with serum testing of their testosterone, estradiol, and progesterone levels. If any of these hormones rise above normal serum range, I cut back on the HCG dosage.
Forest Tennant, MD, DrPH