Symptom duration and spontaneous activity in lumbosacral radiculopathy

Objectives: A long-held notion in the electrodiagnostic literature is that paraspinal muscles tend to show spontaneous activity (fibrillations and pos itive sharp waves) on needle electromyography, early on in a lumbosacral ra diculopathy, and that more distal muscles become abnormal later in the dise ase process. The purpose of this study was to determine whether paraspinal muscle and other major proximal and distal muscle spontaneous activity is r elated to a lumbosacral radiculopathy symptom duration, Methods: A multicenter, prospective study that collected standard informati on on history, physical examination, and electrodiagnostic findings in pati ents with electrodiagnostically confirmed lumbosacral radiculopathies was u ndertaken, Results: Multivariate probit analyses of 96 patients identified with a lumb osacral radiculopathy showed no evidence of correlation between spontaneous activity in the paraspinal muscles and symptom duration, Symptom duration was also nonsignificant in nine of the remaining ten lower limb muscles ana lyzed. Conclusion: These findings emphasize the limitations of using symptom durat ion when interpreting electrodiagnostic findings in lumbosacral radiculopat hy.