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

Abstract

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. 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. 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. 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.