Diagnosing pain—especially chronic or recurrent pain—is a neglected art. However, if certain well-known neurophysiological principles are applied, diagnoses can be made in systematic and logical ways. An example of this can be found in thinking about “glove and stocking” pain.
Treating “glove and stocking” leg pain after failed back surgery
“Glove and stocking” pain is sometimes described as “non-anatomical,” meaning that the pain cannot be explained by existing knowledge of anatomy. In fact, the patient may be suspected of having pain of psychogenic origin or even an agenda of secondary gain. The “psychogenic” part may not be far from the truth in certain cases, but the whole phenomenon is better explained by recognizing that “glove and stocking” pain is mediated primarily by the autonomic nervous system (ANS).
ANS-mediated pain has certain distinctive characteristics. It may have a burning, hot or tingling quality and may be hard for the patient to localize. Sufferers may complain of the pain in an obsessive way—hence accusations of “neurotic” pain. Often, little can be found on physical examination but skin temperature may be altered (either warmer or colder) and subtle changes in moisture and color may be detected. In its most extreme presentation, it is easily recognized as “sympathetic dystrophy.”
Case in Point:
A 40-year-old woman underwent lumbar discectomy for left-leg sciatica. The surgery appeared to be successful with complete relief of leg pain, but after a few weeks another leg pain came on, more diffuse in distribution and different in quality. Physical examination indicated no nerve root signs and over 80 degrees of straight leg raising. MRI of the lumbar spine showed no sign of nerve root compression.
Autonomic response testing indicated an “interference field” (or focus of electrophysiological instability) in the surgical scar. The scar was infiltrated with a few cc’s of procaine ½% followed by an intravenous bolus of the same solution and the leg pain immediately disappeared. After about four days, the pain returned with a slightly greater intensity. Again an interference field was found in the scar and was treated as before. This time the pain relief lasted two weeks and the pain was less intense on relapse. A third treatment resulted in a permanent cure.
Treatment of failed-back-surgery syndrome is one of the most spectacular applications of neural therapy. An interference field in the surgical scar is the most likely cause, with an interference field in the ipsilateral third lumbar sympathetic ganglion the next most common.
Injection of the sympathetic ganglion is equally effective and although technically more difficult than scar injection, can be learned easily and performed in an office setting. (Injection of ganglia in neural therapy does not require the same accuracy as deep injections of anesthesia).
Alternatively, injections can be avoided altogether by treatment with an electrophysical device. The TensCam™, available from Charles Crosby, DO (407-823-9502), is recommended and seems to work as well as injections.
Robert F. Kidd, MD, CM