A flexible catheter includes two electrical contacts in a distal region of the catheter and a distal aperture of a hose line. The electrical contacts are connected to a high frequency pulse generator for applying pulsed radio frequency energy for nerve stimulation. A temperature sensor is located in the distal region of the catheter. The flexible catheter is inserted into a region in the spinal canal and the pulsed radio frequency generator is operated, thereby applying pulsed radio frequency energy to a localized region to be treated. The temperature at the distal region of the catheter can also be monitored, and the pulsed radio frequency energy is applied in dependence on the monitored temperature. With the catheter, pain and other medical conditions being related to and influenced by a nervous system are treated.
