Cervical radiculopathies: Relationship between symptom duration and spontaneous EMG activity

The purpose of this multicenter study was to prospectively examine whether denervation in paraspinal muscles (PSM) and in other major proximal and dis tal muscles is related to symptom duration in cervical radiculopathies (CRs ). Information was collected on 93 electrodiagnostically confirmed CRs usin g standardized history, physical examination, and electromyographic (EMG) s creens. Multivariate, maximum-likelihood estimates showed no evidence of co rrelation between PSM spontaneous activity and symptom duration. Symptom du ration was also nonsignificant in eight of the remaining nine upper limb mu scles analyzed. We conclude that the probability of spontaneous activity is not related to symptom duration. Clinicians, therefore, should refrain fro m interpreting electrodiagnostic findings based upon duration of symptoms. (C) 1999 John Wiley & Sons, Inc.