MMPI Indicators of Treatment Response to Spinal Epidural Stimulation in Patients with Chronic Pain and Patients with Movement Disorders

Abstract

The usefulness of the Minnesota Multiphasic Personality Inventory (MMPI) for predicting treatment response to electrical spinal epidural stimulation was examined in 11 patients with chronic pain and 11 patients with movement disorders. The movement-disordered group had generally lower MMPI scores than the group with chronic pain and higher subjective ratings of improvement. However, physicians' ratings for the group as a whole showed that scores on Hs and Hy, while elevated, tended to be relatively lower for patients who were treatment resistant than for those rated as successes. Higher elevations on D were associated with treatment failure. The “conversion V” profile as an indicator of treatment resistance did not hold for this sample. The psychological implications of these findings are discussed. The results suggest that the MMPI has predictive value but the need for refinement of outcome measures and further clarification of psychological variables is evident.