Spinal Cord Stimulation in Failed Back Surgery Syndrome: Effects on Posture and Gait-A Preliminary 3D Biomechanical Study.

We studied 8 patients with spinal cord stimulation (SCS) devices which had been previously implanted to treat neuropathic chronic pain secondary to Failed Back Surgery Syndrome. The aim of our study was to investigate the effects of SCS on posture and gait by means of clinical scales (Short Form Health Survey-36, Visual Analogue Scale for pain, and Hamilton Depression Rating Scale) and instrumented evaluation with 3D Gait Analysis using a stereophotogrammetric system. The latter was performed with the SCS device turned both OFF and ON. We recorded gait and posture using the Davis protocol and also trunk movement during flexion-extension on the sagittal plane, lateral bending on the frontal plane, and rotation on the transversal plane. During and 30 minutes after the stimulation, not only the clinical scales but also spatial-temporal gait parameters and trunk movements improved significantly. Improvement was not shown under stimulation-OFF conditions. Our preliminary data suggest that SCS has the potential to improve posture and gait and to provide a window of pain-free opportunity to optimize rehabilitation interventions.