A system for controlling operation of a radiofrequency treatment device to apply radiofrequency energy to tissue to treat tissue to create lesions without ablating the tissue. The system includes a device having flexible outer tube, an expandable basket having a plurality of arms movable from a collapsed position to an expanded position, a plurality of electrodes movable from a retracted position to an extended position to extend through the openings in the arms, and an advancer slidably disposed within the outer tube to move the electrodes. An elongated spacer is positioned within the outer tube, the spacer having a central lumen to receive the advancer and to maintain a central position of the advancer.
