Radiofrequency (RF) power has long been recognized as a tool useful in production of experimental lesions in brains of animals* and therapeutic lesions in man.† However, attempts to quantitate lesion size in terms of input power, current, voltage, or dial settings related to these parameters have not produced uniform results. Among the several reasons for these difficulties are differences in circulation from brain to brain and in different parts of the same brain, and differences in impedance, as well as the problems inherent in an accurate measurement of the power or current actually supplied to the nervous tissue.
We felt that quantitation in terms of brain temperature at electrode tip, time of maintenance of temperature, and dimensions of electrode would provide the best index of size of the resulting lesion, since these parameters directly describe the effect by which RF current produces tissue damage.
In this study, 54 lesions were