Neuromodulation of Lidocaine Cream Effect on Chronic Pain Patients

Inclusion Criteria: * Volunteers 21-60 years of age. * Meets the Classification Criteria of chronic LBP (having low back pain for more than 6 months), as determined by the referring physician. * At least 4/10 clinical pain on the 11-point LBP VAS (criteria recommended by Dworkin et al.) * At least a 10th grade English-reading level; English can be a second language provided that the patients understand all questions used in the assessment measures. Exclusion Criteria: * Specific causes of back pain (e.g., cancer, fractures, spinal stenosis, infections). * Complicated back problems (e.g., prior back surgery, medicolegal issues). * The intent to undergo surgery during the time of involvement in the study. * History of cardiac, respiratory, or nervous system disease that, in the investigator's judgment, precludes participation in the study because of a heightened potential for adverse outcome. For example: asthma, claustrophobia, epilepsy or acute eczema under the electrodes. * Presence of any contraindications to MRI scanning. For example: cardiac pacemaker, metal implants, claustrophobia, pregnancy, cannot lie still in an fMRI scanner. * History of medical or psychiatric illness. * History of substance / alcohol abuse or dependence.