Hippocampal Stimulation in Chronic Low Back Pain

Inclusion Criteria: * ≥ 6 months of back pain on a daily basis; * male or female with no racial or ethnic restrictions; * 18 to 75 years old; * average back pain intensity \> 4/10 at study entry; * must be able to read, understand, and sign consent form; * generally healthy. Exclusion Criteria: * back pain with fever, chills, rheumatoid arthritis, ankylosing spondylitis, acute vertebral fractures, * history of tumor in the back; * back surgery within the past 6 months; * Chronic neurologic conditions, e.g., Parkinson's * involvement in litigation regarding back pain; * other severe medical diseases; * pregnancy; * positive urinary screen for any recreational drugs, * opioids use; * use of anticoagulants (low dose ASA allowed); * history of gastric ulcer; renal insufficiency or congestive heart failure, * contraindication to MRI, * contraindication to TMS; including history of seizure/epilepsy\* * Any medical condition that in the investigator's judgment may prevent the individual from completing the study or put the individual at undue risk; * In the judgment of the investigator, unable or unwilling to follow protocol and instructions; * Diagnosis of major depression; * Intra-axial implants (e.g. spinal cord stimulators or pumps)