Offset Mechanisms in Evaluation of Lumbar Medial Branch Blocks

This study examines the relationship between central nervous system (CNS) mechanisms of pain inhibition and the pain relief that occurs following a commonly-performed nerve block used to diagnose and treat chronic low back pain. Patients scheduled for lumbar medial branch blocks as part of routine clinical care will arrive to clinic prior to the block for quantitative sensory testing procedures that measure CNS pain modulation. Patients will then undergo treatment as usual with their block, subsequently reporting low back pain intensity in a pain diary.