Purpose: Since the introduction of spinal cord stimulation for the treatment of chronic neuropathies (Shealy, 1967), further development has identified indications. The objective of this prospective multicentric protocol was to quantify clinical and economical results in a homogeneous group of rigorously selected patients.

Material and methods: In 1999, nine university hospital centres recruited 43 patients (22 men, 21 women, mean age 50.8 years) with chronic postoperative neuropathic sciataligia insufficiently controlled by antiseizure and antidepressor (tricyclic) drugs. There were 34 unilateral cases and nine bilateral cases and 60% of the patients also had lombalgia. Diagnosis was established on the basis of history taking, clinical signs, and anatomic and electrophysiological findings. Indications for spinal cord stimulation were determined in a pluridisciplinary context including a psychological evaluation. A temporary test was made before implanting the programmable neurostimulator (Itrel®II or Itrel®3, Medtonic) in order to check that the induced paresthesia involved the painful territory. Included patients were assessed before implantation then at six (39 patients), 12 (30 patients) and 24 months after institution of the stimulation. At each follow-up visit, the clinical effect was assessed with validated pain scales (visual analogue scale, McGill Pain score, Oswestry incapacity score). Economical data were obtained from the medical file, patient interviews, and a specific therapeutic follow-up chart. Preliminary results (mean follow-up 10 months) are presented.

Results: Clinical scores improved 40 to 50% one year after implantation of the neurostimulator. There was significant relief of sciatalgia: on the visual analogue scale the mean pain score (7.8/10 before implantation) was 2.7/10 (p < 0.05) and 3.6/10 (p < 0.05) at six and 12 months after implantation. Drug prescriptions (antiseizure, antidepressors) were reduced by 70%. Residual treatments were prescribed for lumbalgia which was relieved little by stimulation. Annual expenditures (drugs + visits + non-drug treatments) was reduced by 1578 euros per patient (mean). Hospitalisation rate fell from 26% to 10% and the rate of resumed occupational activities was 11%

Discussion: Assessment of 24 patients after implantation of a neurostimulator will complete these early results.