No consistent methodology used in application of RF to allow valid comparisons.

With interest, we read the article from Simopoulos et al (1). We have extensively utilized pulsed radiofrequency applications for radicular pain for greater than 10 years. As published earlier (1), it is our experience that outcome is directly related to the proximity of the radiofrequency electrode to the targeted neural structure. Thus, positive stimulation at 50 Hz at less than 0.2 volts would be preferable to accepting higher thresholds of less than 0.6 volts. Moreover, by decreasing tissue impedance with normal saline injection, when necessary, the consistent delivery of greater than 200 milliamps of current was possible without exceeding tissue temperatures of 42 degrees Celsius. In our study (2), 8 patients have reported satisfactory relief of radicular pain for 7±3.8 months. We point out these differences to make the point that there is not a consistent methodology used by investigators in the application of radiofrequency to allow valid comparisons of patient outcomes.