Physical performance decreases in the early stage of cervical myelopathy before the myelopathic signs appear: the Wakayama Spine Study.

PURPOSE: We previously revealed a prevalence rate of 24.4% for cervical cord compression (CCC) in a population-based magnetic resonance imaging study. This study aimed to investigate the occurrence of cervical myelopathy (CM) among CCC cases and to reveal the predictors for CM.

METHODS: This study is a part of "The Wakayama Spine Study," a large-scale population-based MRI cohort study. At baseline, 238 patients were diagnosed with CCC. We followed 238 patients who had CCC for more than 4 years, of which 158 (mean age, 68.9 years) participated in the second survey (follow-up rate, 66.3%). In the second survey, de novo CM was defined clinically as the presence of myelopathic signs (e.g., Hoffmann reflex, hyperreflexia of the patellar tendon, and Babinski reflex). Physical performance on 10-s grip and release test (GRT), grip strength, 6-m walking time at a usual and a maximal pace, step length at a usual and a maximal pace, chair stand time (CST), and one-leg standing (OLS) time was measured.

RESULTS: Among the 158 participants, nine (mean age, 68.8 years; incidence rate, 6.3%) were newly diagnosed with CM in the second survey. CST, 6-m walking time at a usual and a maximal pace, and step length at a maximal pace had already decreased in the de novo CM (+) participants at baseline compared to baseline findings of de novo (-) CM participants, but not the grip strength, OLS, or GRT.

CONCLUSIONS: We clarified the incidence rate of CM in CCC patients and the predictors of de novo CM. These slides can be retrieved under Electronic Supplementary Material.