Effects of tDCS and TUS on the Perception of Pain and Functional Limitations Due to Non-Specific Chronic Low Back Pain

Inclusion Criteria: 1. Able to provide informed consent to participate in the study 2. Subjects between 18 to 85 years old 3. Subjects having non-specific chronic low back pain with existing pain for at least 3 months and having pain on at least half the days in the past 6 months with an average of at least 3 on a 0-10 visual analog scale (VAS) scale 4. Pain resistant (partial or no response) to common analgesics and medications for chronic pain used as initial pain management such as Tylenol, Aspirin, Ibuprofen, Soma, Parafon Forte DCS, Zanaflex, and Codeine. 5. Must have the ability to feel sensation by Von-Frey fiber on the forearm Exclusion Criteria: 1. Subject is pregnant 2. Contraindications to tDCS in conjunction with TUS, i.e. metallic implant in the brain or implanted brain medical devices 3. History of alcohol or drug abuse within the past 6 months as self reported 4. Use of carbamazepine within the past 6 months as self reported 5. Suffering from severe depression (with a score of \>30 in the Beck Depression Inventory) 6. History of neurological disorders as self reported 7. History of unexplained fainting spells as self reported 8. History of severe head injury resulting in more than a momentary loss of consciousness as self reported 9. History of neurosurgery as self reported 10. Unstable pain 11. Large placebo responder 12. Low adherence during the run-in period 13. Low baseline pain