Characteristics of Patients Achieving Clinically Meaningful Improvement in Neuropathic Pain After Surgery for Degenerative Cervical Myelopathy.

Abstract

Study DesignRetrospective analysis of a prospectively maintained multicenter cohort.ObjectivesTo identify clinical characteristics associated with clinically meaningful improvement in neuropathic pain and to evaluate its relationship with postoperative functional outcomes in patients with degenerative cervical myelopathy (DCM).MethodsAmong 816 patients with complete Neuropathic Pain Symptom Inventory (NPSI) data, 597 with baseline total NPSI scores ≥7 were included in the primary analysis because they were eligible to achieve the predefined minimal clinically important difference (MCID) of a 7-point reduction. Patients were classified as responders or non-responders according to MCID achievement at 2 years postoperatively. Clinical outcomes included the cervical Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS), Short Form-36 (SF-36), and JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ).ResultsOf the 597 patients, 323 (54.1%) achieved the NPSI MCID. Responders had significantly higher preoperative total NPSI scores than non-responders, whereas no significant differences were observed in baseline JOA, VAS, or SF-36 scores. Responders demonstrated greater improvement in upper-extremity pain and numbness and in the SF-36 mental component summary score. They also showed significantly higher effectiveness rates in the upper-extremity, lower-extremity, bladder, and quality-of-life domains of the JOACMEQ.ConclusionsClinically meaningful improvement in neuropathic pain after surgery for DCM was associated with broader postoperative recovery across pain-related, functional, mental health, and quality-of-life outcomes. Assessment of neuropathic pain may provide clinically relevant information complementary to conventional measures of neurological function.