A psychoanalytic investigation to improve the success rate of spinal cord stimulation as a treatment for chronic failed back surgery syndrome

Objective: The analysis of patient data concerning psychological structure and functioning produced an instrument to determine whether a neurostimulator ought to be implanted or not. Design: A questionnaire containing 24 items was developed by a psychologist and tested in 40 chronic failed back surgery patients for whom a spinal cord stimulation seemed to be the only therapeutic approach. This questionnaire was based upon some crucial psychological themes, on which the patient took a position. A predictive indication factor (I.F.; %) for implantation of the neurostimulator was obtained from the 24 items. Six months after the implantation of the neurostimulator, we correlated the evaluation factor (E.F.; %) with a six-point evaluation scale considering the pain reduction. The aim was to compare the I.F. and E.F. to verify the correlation between them. This comparison was intended to answer the question if psychological variables included in our scale improve the success rate of the therapy. Setting: Data were collected by a psychologist at the Pain Clinic of the University Hospital of Gent, Belgium. Results and Conclusions: The correlation between the I.F. and the E.F, was calculated for the 40 patients by the Spearman correlation test. A coefficient value of 0.8083 (p = 0.000) was found, indicating the existence of a very close correlation between the predictive I.F. and the E.F. The indication scale appears to be a useful instrument for clinical psychologists to predict the success rate of a spinal cord stimulator in this group of patients.