#6 Discoveries

Possessing the first device capable of measuring nerve VGC function, the focus was on painful radiculopathy. Several colleagues referred patients with well defined nerve root lesions, so I could see if any particular sensory fiber matched these lesions. After almost 100 sets of tests were available, no correlation was found between the suspected lesions and A-beta or C-Type fibers. However, the A-delta fibers of the suspected nerve root required stronger voltage to create threshold action potentials in all but about 15% of cases. In these cases dysfunction was found, but not in the suspected nerve root and a few found dysfunctions on the opposite side form the suspected lesion. In each of these non-matching cases the referring doctor reported that the patient was not responding well to treatment. When told which nerve root seemed to be the problem and the treatment was then focused on that nerve root, all the patients reported far greater improvement.

The next discovery involved DCs being trained in manipulation under anesthesia (MUA). Part of the standard MUA protocol is taking side bending radiographic views in which the greatest degree of vertebral rotation occurs. These views allow detection of spinal joints fixated by adhesions. I performed the painless Pain Fiber F-NCS on many of the patients scheduled for MUAs with very interesting results. I found that the vertebrae adjacent to an involved nerve root rotated abnormally. Apparently, when the Fast Pain A-delta fibers loose sensitivity, there is a corresponding reduction in proprioception. I found that when a lesion is distal to the intervertebral foramen there is no abnormal vertebral rotation, however, lesions at the vertebral foramen disrupt proprioception of the vertebral joints and reverse rotation results.

The confusion as to the level and side of lesion made sense, because I had noticed over the years that if a whiplash patient was seen within an hour of their accident s/he pointed out nerve root patterns different from those pointed out the next day. Many even complain that the major area of pain moved to the opposite side. This caused me to suspect referred pain was at work.

Textbooks never explained somatic referred pain. When the subject comes up the explanation quickly shifts to referred pain due to organ disease. One can find nothing dealing with nerve root referred pain. It is literally a Blind Spot in the literature.

Medical physiology texts, such as Guyton & Hall, have for decades reported how during the acute Epicritic Phase of nerve injury the excellent localizing A-delta fibers up-regulate. The (Fast Pain) A-delta fibers synapse with spinal cord motor neurons initiating the Withdrawal Reflex that moves the body away from the source of injury. Guyton explains that the Epicritic Phase is followed by the Protopathic Phase in which poor localizing C-Type fibers up-regulate; “This explains why so many patients have serious difficulty localizing the source of some types of chronic pain.” However, let’s be clear, no patient has ever said; “I am having ‘serious difficulty’ localizing my pain. S/he simply and unknowingly misdirects attention to a healthy nerve root. As for “some types of chronic pain” Guyton should be clear that this is the most common type of pain driving 25% of patients to seek medical care – radiculopathy.

Guyton never mentions what I discovered: During the Protopathic Phase, while C-Type fibers up-regulate simultaneously the excellent localizing A-delta fibers down-regulate, thereby, increasing the likelihood patients will inaccurately localizing the source of their pain.

A few years later AASEM certified physicians formed a consensus that over 50% of patients identify the wrong nerve root as the source of radiculopathic pain, while half of these patients are so confused they localize the source of pain to the wrong side. There are two sure ways to know which nerve is injured; skin biopsy and F-NCS. A Chicago based neurology group compared the F-NCS to skin biopsy and found a direct correlation, except in very acute cases where the F-NCS detected dysfunction a week or more before the skin biopsy could detect nerve damage.