Spectrum of patients with EMG features of polyradiculopathy without neuropathy

We reviewed the medical records of 233 patients having electrodiagnostic evidence of polyradiculopathy. Patients with polyneuropathy or incomplete diagnostic evaluation were excluded. A clinical diagnosis was secured in 92 of the 118 remaining patients. Patients were separated into three groups based upon the anatomic location of root involvement: extradural (55), intradural-extraaxial (23), and intraaxial (14). Collectively, patients with intradural-extraaxial disorders had earlier disease onset, shorter symptom duration, and a higher disability score compared with the intraaxial or extradural groups. Pain was an initial complaint in 50 of 55 patients with extradural lesions, 20 of 23 with intradural-extraaxial disease, but only in 4 of 14 with intraaxial involvement. CSF abnormalities and reduced compound muscle action potential amplitudes were more common in the intradural-extraaxial group. We conclude that the anatomic localization of root involvement in patients with polyradiculopathy can be suggested by a combination of clinical, laboratory, and electrodiagnostic features.