Pregabalin Versus Acetaminophen for a Treatment of Chronic Neuropathic Painon Extremities after Cervical Surgery: A Prospective Randomized, Open-LabelPreliminary Study

Therapeutic efficacy of pregabalin (PGL) for reducing neuropathic pain in patients who received a cervical operation is unclear. The purpose of this prospective pilot study was to compare the efficacy and adverse events between PGL and acetaminophen (ACM) for residual neuropathic pain. Thirty-four patients who received cervical spine surgery at our hospital from September 2011 to April 2013 and were diagnosed with residual neuropathic pain in the extremities were enrolled and were randomized to receive PGL (50 mg/day initially as an induction dose for 2 weeks) or ACM (1200 mg/day) for 8 weeks. PGL dosage was adjusted to 50-150 mg/day according to the severity of pain using a visual analog scale (VAS) after a 2-week time point. The Neck Disability Index (NDI) and VAS were used to evaluate subjective pain of the extremities and sleep condition. Short Form-36 (SF-36) and Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) were used to evaluate neurologic function. Thirty-three patients (PGL 19 cases, ACM 14 cases) completed 8 weeks of follow-up. The average VAS for pain and numbness significantly improved in both groups at the final visit. The scale for sleep improved in the PGL group but was unchanged in the ACM group. The proportion of patients with satisfactory improvement in sleep was 31.6% and 0% in the PGL and ACM groups, respectively. There was a significant difference in VAS for sleep only. There were no significant improvements in the NDI and each domain of JOACMEQ in both groups. The number of patients who complained of somnolence tended to be greater in the PGL group. Thus, both PGL and ACM administration improved residual neuropathic pain in patients treated with cervical spine surgery for myelopathy. PGL was more effective in reducing sleep interference related to refractory neuropathic pain compared with ACM.