I am researching the criteria for a pulsed radiofrequency procedure vs. a thermal radiofrequency procedure for the thoracic intercostal nerves. Normally a pulsed radiofrequency procedure is coded as 64999 as an unlisted procedure and is considered investigational and experimental by most payers. I am trying to get a clear definition of the pulsed procedure and the destruction of the intercostal nerve code 64620.