Transcriptomic Profile of Patients Treated With Different Modalities of Spinal Cord Stimulation

Failed Back Surgery Syndrome (FBSS) is a relatively common condition that can cause a severe disability in patients. Spinal cord stimulation (SCS) is used in those patients refractory to conventional therapies.In this project the investigators aim to identify new functional molecular basis, defined with transcriptomic profiling, differentially represented in the serum of patients suffering chronic pain caused by FBSS.The investigators will try to Identify "omics" markers for diagnosing and monitoring the process of development and maintenance of pain as well as the evaluation of these as evolutionary disease markers or predictors of the response to SCS therapy. To carry out the project, 40 patients diagnosed with refractory FBSS and treated with an SCS system for pain management will be included. Blood samples will be obtained to analyze the transcription profiling in plasma of patients responding to different modalities of SCS therapy.

Inclusion Criteria:Adult patients affected by FBSS, defined as "surgical end stage after one or several interventions on the lumbar neuroaxis indicated to relief lower back pain, root pain or the combination of both, without effect"Age between 18 and 65 yearsSevere pain measured on a numerical rating scale (NRS > 6/10), more than six months of evolutionRefractory pain despite having carried out pharmacological treatment according to WHO's stratified approach; physical/rehabilitation therapy and/or interventional procedures (e.g. epidural steroid injections, radiofrequency, epiduroscopy/adhesiolysis)Exclusion Criteria:Patients with severe associated comorbidities (e.g. severe high blood pressure, diabetes mellitus, peripheral vasculopathy, severe heart disease, etc...) that may in themselves cause pain or aggravate the existence of previous pain.Extensive osteosynthesis encompassing the thoraco-lumbar region where the tips of the electrodes are routinely positioned.Abnormal pain behavior, unresolved psychiatric illness, unresolved issues of secondary gain or inappropriate medication usePatients not consenting or refusing to participate will be excludedNegative evaluation of the psychologist previous to the implant