Disc problems (short of a disc herniation that compresses nerve roots) will not cause nerve pain. With a normal EMG and normal biopsy, this leads to a diagnosis of idiopathic neuropathy. This simply means that we have not discovered the cause as our testing is not precise enough. Discograms will only diagnose disc pain generators and will not be helpful in your case.
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.