RELATIONSHIP BETWEEN MUSCLE ABNORMALITIES AND SYMPTOM DURATION IN LUMBOSACRAL RADICULOPATHIES

A long held notion in the electrodiagnostic literature is that paraspi nal muscles tend to show electromyographic abnormalities early on in a lumbosacral radiculopathy and that more distal muscles become abnorma l later in the disease process. The purpose of this study was to deter mine whether paraspinal muscles and other major proximal and distal mu scle abnormalities are related to lumbosacral radiculopathy symptom du ration. A multivariate legit analysis of 139 patients (retrospectively identified) with electrodiagnostically confirmed lumbosacral radiculo pathies was used to test these hypotheses. Maximum likelihood estimate s showed no evidence of correlation between abnormal paraspinal muscle s and symptom duration. Symptom duration was also insignificant for th e remaining five lower limb muscles analyzed. We conclude that the pro bability of having electromyographic abnormalities is not related to s ymptom duration. A prospective study is needed to confirm these findin gs. Nonetheless, clinicians should use caution when interpreting elect rodiagnostic findings based on symptom duration.