Significance of pure sensory manifestations in estimating electromyography results in cervical radiculopathy

Background: The sensitivity of electromyography (EMG) in cervical radiculopathy (CR) is reportedly higher in patients with objective neurological findings, but many patients are sent to the EMG laboratory with only pain and paresthesias. Aims: We aimed to assess the diagnostic contribution of EMG in patients with sensory manifestations without objective neurological deficits. Settings and Design: The files of patients with neck pain radiating to the shoulder and arm on the same side referred to the EMG Laboratory were retrospectively evaluated. EMG findings of those with pure sensory manifestations were compared with the results obtained from patients with objective neurological deficits. Subjects and Methods: Patients with subjective sensory manifestations were separated into two groups according to the specificity of the presenting symptoms, who were compared with subjects with neurological findings in the upper extremity. Clinical diagnoses of the patients were compared with the electrodiagnostic testing results. Statistical Analysis: Categorical variables were analyzed with multi-span Chi-square test, while individual groups were compared utilizing Fisher's exact test. One-way analysis of variance was employed to assess the significance of group differences for quantitative values. Results: EMG rarely confirmed CR in patients with purely sensory symptoms. Some of these patients were found to have unexpected peripheral neuropathy syndromes. Both paraspinal and limb muscle EMG abnormalities indicative of CR were not only more common, but also helpful in localization in patients with objective clinical findings. Conclusions: CR patients presenting only with pain and paresthesias even in a specific dermatomal distribution usually demonstrate no abnormalities in EMG examination. However, some of these patients harbor unsuspected entrapment neuropathies.