Pain, Intractable

The purpose of this research study is to identify sensations that can be evoked with spinal cord stimulation (SCS) and to understand how these sensations change when stimulation parameters are modified.

Previous studies have shown that the anterior cingulate cortex is involved in the regulation of pain and its associated negative emotions, that pyramidal neurons are highly excitable in chronic neuropathic pain conditions, and that silencing of pyramidal neurons can eliminate pain. The aim of this study was to evaluate the safety, tolerability, and efficacy of intracranial injection of GA (containing the hM4Di gene) in the anterior cingulate cortex in combination with oral clozapine for the treatment of refractory neuropathic pain.

Number of centres planned : 1 (CHU Nantes) Design : Randomized, Prospective Planning of the study : * Total duration: 34 months * Recruitment period: 24 months. * Follow-up time per patients : 7-10 months Expected number of cases : 12 Treatment, procedure, combination of procedures under consideration : During the study, patients will be implanted with the WAVEWRITER ALPHA™ system with the objective of decreasing patient pain with a spinal cord stimulation mode. There will be a random draw on the order of the stimulation program: * the tonic stimulation "LF": In tonic mode, the electrical stimulation of the sensory fibers of the posterior cords of the spinal cord induces local paresthesias * burst stimulation (or "burst") * high frequency" stimulation (1000 Hz) "High frequency: HF". * combined tonic + burst stimulation * combined tonic + high frequency stimulation

The goal of this clinical trial is to learn about a new management system in chronic and stubborn pain patients who accept therapy of spinal cord stimulation (SCS). Usually, these patients are required to take long-term follow-ups to ensure that the stimulator works well. The main questions it aims to answer are: * Is it better to improve the patient's quality of life than the current conventional follow-up? * Is it better to relieve pain in the long term than the current conventional follow-up? * Is it possible to be applied to a large population of chronic pain patients? Participants will be randomly assigned to either a control group or an interventional group. Participants in the control group will be given the standard SCS implantation surgery and asked to complete the conventional follow-up (at least 1-, 3-, and 6-month post-operative). Participants in the interventional group will be given the standard SCS implantation surgery and asked to do the following things: * Take the daily pain self-assessment questions on a mobile phone APP. * Take the monthly healthy status self-assessment questionnaires on a mobile phone APP. * Take the conventional follow-up (at least 1-, 3-, and 6-month post-operative). Researchers will compare the two groups to see if the life quality of the interventional group is improved.