Neuropathic pain =< grade 
Peripheral neuropathy or neuropathic pain Grade  or higher
History of pre-existing neuropathic pain conditions
Significant preoperative chronic pain (requiring daily narcotics) or neuropathic pain (requiring daily use of pregabalin or gabapentin) within the previous  months
Pain score >=  on a - numeric pain scale and/or grade  neuropathic symptoms according to the National Cancer Institutes  point grading scale
Neuropathic symptoms must be related to chemotherapy (in the opinion of the treating physician)
Patients must report neuropathic pain for a minimum of  months
Score of  or more on Douleur Neuropathique  (DN) neuropathic pain questionnaire
Neuropathic pain score >=  on a - numeric pain scale (numeric rating scale [NRS]) and/or grade  or higher neuropathic symptoms according to the National Cancer Institutes  point grading scale.
Neuropathic symptoms must be related to chemotherapy (in the opinion of the treating physician).
Patients must have had neuropathic symptoms for a minimum of  months.
Pain that is post-operative (<  months since surgery) or neuropathic pain; (Note: grade  chemotherapy-induced peripheral neuropathy [CIPN] is not anticipated to meet threshold criteria on the Neuropathic Pain Screening questionnaire); patients with more than one type of pain who are able to isolate and identify a non-neuropathic pain experience (e.g., persons with diabetic neuropathic foot pain as well as nociceptive cancer-related abdominal pain) may be included with the principal investigator (PI)s approval
Pre-existing neuropathy, neuropathic pain, or nerve injury;
Inflammatory, metabolic or neuropathic arthropathies
GROUP A (painful neuropathy group): Must have subjective symptoms of painful peripheral neuropathy (burning, stabbing, throbbing, painful tingling, aching in the fingers and/or toes) that is greater than or equal to  on a scale of  to  in the neuropathic pain questionnaire