A Diagnostic Approach to Myelopathy Based on Prognostic Factors in Patients With Lower Extremity Symptoms.

STUDY DESIGN: Case-control study. OBJECTIVE: We aimed to identify predictors for latent myelopathy and to develop a diagnostic protocol based on these factors. SUMMARY OF BACKGROUND DATA: There is no diagnostic protocol for latent myelopathy to avoid misdiagnosis in patients complaining only of lower extremity symptoms. METHODS: This case-control study identified 791 patients discussed at conferences from April 2006 to August 2012. Overall, 460 patients complaining only of lower extremity symptoms and who underwent spine surgery were included as participants; 54 underwent surgery involving the cervical and thoracic vertebrae and were assigned to the cervical-thoracic group (C-T group); 406 underwent lumbar surgery and were assigned to the lumbar group (L group). RESULTS: By univariate analysis, age ≥67 years, patellar tendon (PT) hyperreflexia, Achilles tendon (AT) hyperreflexia, spastic gait, and gait inability were more common in the C-T group than in the L group. By multivariate analysis, age ≥67 years (OR, 8; P = 0.001), AT hyperreflexia (OR, 20.5; P < 0.001), spastic gait (OR, 225; P < 0.001), and gait inability (OR, 64; P < 0.001) were significant predictive factors. In patients with age ≥67 years, PT hyperreflexia, and/or AT hyperreflexia, the sensitivity for myelopathy diagnosis was 98%. In patients with spastic gait or gait inability, the specificity of myelopathy diagnosis was 96%. CONCLUSIONS: We analyzed factors that predict latent myelopathy in patients complaining only of lower extremity symptoms. We believe a diagnostic protocol based on the predictors shown in this study would contribute to the accurate diagnosis of latent myelopathy. LEVEL OF EVIDENCE: 4.