Transcutaneous nerve stimulation: its significance and applications in podiatry.
In summation, the neuranatomy and neurophysiology of pain have been presented. Three of the classical theories of pain transmission were also discussed, these being the specificity, pattern, and gate control theories. The gate control theory postulates that stimulation of large diameter sensory nerve fibers blocks pain sensation at the level of the substantia gelatinosa in the dorsal horn of the spinal cord. This theory is used as the basic explanation for the function of the TNS, a device that can control pain by stimulation of the skin through surface electrodes. TNS stimulation appears to be most efficacious when the electrodes are placed either directly over or just proximal to the painful region. Podiatric application appears to lend itself quite naturally to TNS therapy. Several surgical and nonsurgical cases were presented where TNS therapy was employed and in this preliminary study approximately a 63% improvement in pain state was shown. We believe this modality is useful for patients who should limit their intake of analgesic medications, whether they are medically compromised, allergic to various pain medication, or simply are highly intolerant to pain. TNS is also useful in patients who do not respond well to the more traditional and conventional podiatric treatments. Our study illustrates TNS to be efficacious in pain states of a surgical, chronic or acute nature and even pain secondary to systemic disease. It should be noted that TNS is not curative, per se, but is a useful adjunct in the therapeutic regime. This form of therapy, although not without hazard, is relatively safe and easy to use, and although it is not the answer to all pain states, it is highly recommended when applicable.