Hi Thank you for your question to HCM. Relief of symptoms after surgery and recurrence later is generally indicative of either a nonunion at the attempted fusion level or stenosis at an adjacent level. Nonunion at fusion site may be as a result of an infection or smoking. Also levels immediately above and below the fusion are at increased risk of degeneration and stenosis. Appearance of pain after stopping pain medications can usually be treated with certain modifications in pain medications and physical therapy. However new appearance of numbness and weakness leading to frequent falls indicates pressure on the spinal cord. For my patients presenting like this I would do complete neurological examination and evaluate with an Xray and MRI of the cervical spine with contrast. A CT scan will diagnose nonunion if the suspicion is high. Hope this is helpful. I would be happy to answer any questions.