It was previously thought that tissue temperatures during Pulsed RF did not exceed the control temperature of 42 °C as measured by a clinical RF generator. However, using both finite element computation and ex vivo experimentation, Drs. Cosman and Cosman showed that Pulsed RF lesioning (PRFL) produces heat bursts at points of high curvature on the electrode tip's surface. These heat bursts are highly localized and transient, but have peak temperatures in the range associated with destructive heat lesions. PRFL also produces very high electric fields that may be capable of disrupting neuronal membranes and function.
Drs. Cosman and Cosman frame the possible physical effects of the electric and thermal fields around pulsed radiofrequency electrodes. In additional to the possible neruolytic effect of the heat flashes themselves, they propose theoretic possibility of membrane distruption, such as electroporation, and the disruption of intracellular stuctions. Drs. Cosman and Cosman also propose the possibility that Pulsed RF is having a neuromodulatory effect, long term depression (LTD), by simulating primary sensory fibers at a level that is subtreshold postsynaptically.
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