Rationale: Central neuropathic pain resulting from spinal cord injury is notoriously debilitating and difficult to treat with few currently available treatments. A novel molecule with intrathecal administration: Ziconotide has been approved for treatment of refractory neuropathic pain in general. It acts as a presynaptic calcium channel blocker. A pilot study has shown its potential in SCI neuropathic pain patients. Objective: The aim of this study is to determine the long-term (6 months) efficacy of chronic intrathecal ziconotide for the treatment of neuropathic SCI pain. Study design: Multicenter, Randomized, Comparative, Placebo controlled, Double blind clinical trial, with a crossover of random alternated periods of 6 months (placebo or ITZ) for a total of 15 months including a total of 44 patients. Study population: • Patients with SCI of various etiologies exhibiting neuropathic pain refractory to non-invasive treatments. • > 18 years. Intervention: Intrathecal administration of ziconotide via an implanted pump. Study outcomes: Primary study outcome Difference in pain intensity for all patients between effective treatment and placebo periods. Secondary study outcomes 1. Continuous evaluation of pain intensity. 2. Percentage of patients with at least 30% of pain reduction. 3. Satisfaction level of the patient pain relief. 4. Declarations of serious adverse events. 5. Duration and intensity of spontaneous and provoked pain. 6. Quality of life. 7. Patient global impression of change. 8. Quantification of daily dosages of analgesic drug intake. 9. Long term memory and neurocognitive effects. 10. Assessment of the patient's physical and emotional distress. NATURE AND EXTENT OF THE BURDEN AND RISKS ASSOCIATED WITH PARTICIPATION, BENEFIT, AND GROUP RELATEDNESS: Participation in this study is in accordance with current treatment protocols for SCI neuropathic pain in France therefore it proposes a treatment that would currently be considered regular practice even though no RCT evidence is yet available. The study gives patients the advantage of directly testing versus placebo a treatment that otherwise entails significant constraints. A Data Safety Monitoring board (DSMB) will be created for continuous safety analysis. Furthermore, patients will be followed in specialized pain centers offering the possibility of continuing their treatment after the study period.