Correlation of Electrodiagnostic Findings in C8 Radiculopathies With Radiographic Data: A Retrospective Chart Review.

ABSTRACT: Signs and symptoms of a C8 radiculopathy could mimic common comorbidities such as entrapment and peripheral neuropathies. These conditions and a C8 radiculopathy both can result in abnormal findings on needle examination of intrinsic hand muscles. It was hypothesized that needle examination of C8-innervated muscles in the forearm might improve concordance with magnetic resonance imaging (MRI) in the presence of underlying comorbidities. A retrospective analysis of electromyogram and C-spine MRI data in 80 patients with negative MRI of C-spine for C8-T1 neuroforaminal stenosis was performed. The percentage of false-positive results in the MRI-negative group undergoing electromyogram testing for hand and forearm muscles (MRI-NH + F) was 3% compared with 18% (P = 0.06) in the group with electromyogram of the hand intrinsic muscles only (MRI-NH). The false-positive result tends to be lower in the MRI-NH + F group in comparison with the MRI-NH group especially in the presence of underlying peripheral and entrapment neuropathies.