RecruitingDevice studyTherapeutic Mechanisms of Epidural Spinal Cord StimulationThe purpose of this study in patients undergoing routine care epidural spinal cord stimulation (SCS) is to determine 1) whether SCS reduces arterial blood pressure (BP) in patients which chronic low back pain and hypertension, 2) whether higher baseline BP (i.e., hypertension) predicts reductions in pain following SCS, and finally 3) whether different SCS waveforms elicits stimulus-evoked compound action potentials (ECAPs) in spinal cord and at the cortex (electroencephalography, and magnetoenchphalography).