[First Experiences with peripheral Nerve Stimulation using an implantable System as a Treatment Method for the Complex Regional Pain Syndrome CRPS 2]. / Erste Erfahrungen mit der peripheren Nervenstimulation mittels implantierbarem System als Behandlungsmethode des komplexen regionalen Schmerzsyndroms CRPS 2.

ABSTRACT

INTRODUCTION: Peripheral nerve stimulation (PNS), based on central nerve stimulation (Spinal Cord Stimulation - SCS), has proven to be a suitable therapy option for the treatment of complex regional pain syndrome (CRPS), especially in the area of the upper extremities. However, the evidence on PNS in the current literature is very scarce. MATERIAL AND METHODS: 11 patients suffering from CRPS 2 were selected for implantation of a peripheral nerve stimulation system according to strict selection criteria. There were 5 men and 6 women with a mean age of 46.4 (24-58) years. Preoperatively, the mean pain score quoted by the patients was 8.0 (±1.3) on the ten-part numeric rating scale (NRS). In 8 patients, electrodes were implanted in the upper extremity (brachial plexus), in 2 patients in the area of the lower extremity (sciatic nerve) and in one patient on both the upper and lower extremities. The 8 active electrode poles were implanted as parallel as possible on the target nerves and connected to an external stimulation device by means of extension electrodes. After a test phase of 5 days, with positive feedback by the patients and a pain reduction of at least 4 points on the NRS, objectified by a pain log kept by the patient, the definitive impulse generator was implanted. RESULTS: All 11 patients were successfully supplied with an implantable peripheral nerve stimulation system from Boston Scientific Inc. The mean pain reduction was 4.6 (±1.2) points on the NRS. The mean pain score postoperatively was 3.4 (±0.9). The postoperative course was uncomplicated in all patients. CONCLUSION: Peripheral nerve stimulation appears to be a suitable therapy option for the treatment of CRPS 2 when conservative and conventional surgical treatment methods have failed. The experience with our patients shows that neuropathic pain could be successfully reduced by an average of about 4 points on the NRS. Arthrogenous symptoms, on the other hand, were not influenced by the PNS. Since CRPS is a psychosomatic illness, the integration of PNS into a multimodal therapy concept with physiotherapy and occupational therapy and psychology is essential for the success of the treatment.