Usefulness of electrophysiological studies in the diagnosis of lumbosacral root disease

Abstract

Clinical, electrophysiological, and myelographic findings were correlated in 57 patients with the clinical diagnosis of lumbosacral root disease. Conventional motor and sensory (including sural nerve) conduction studies were normal in all patients. Electromyography, late response studies in different muscles of the lower extremity, the myelogram, or combinations of these tests were abnormal in 44 patients (77%). Of 36 patients (63%) with abnormal myelograms, 14 had normal electrophysiological studies. Twenty-nine (51%) had an abnormal electrophysiological or myelographic finding; although 8 patients in this group had a normal myelogram, 2 had an abnormal discogram and 1 an abnormal epidurogram. Electrophysiological or myelographic findings, in some cases both, correlated well with clinical signs and symptoms in 41 patients (72%). H-reflex and F response studies, when abnormal, helped in localizing a lesion in the appropriate root distribution.

Electromyography and magnetic resonance imaging in the evaluation of radiculopathy

“…Studying patients with low back pain radiating down one leg, Haldeman 6 and Khatri 9 found EMG abnormalities in 36% and 64% of patients, respectively. In studies of patients with an abnormal physical examination as well as a history consistent with radiculopathy, EMG abnormalities have been reported in 51-86% of patients, 2,12,13,16,19 which is similar to our figure of 72% in the subgroup of 25 patients with abnormal findings on neurologic examination. MRI abnormalities correlating with the clinically estimated level of radiculopathy were present in 57% of our patients.…”

Short-Latency Somatosensory-Evoked Potentials From Radial, Median, Ulnar, and Peroneal Nerve Stimulation in the Assessment of Cervical Spondylosis

“…The rate of EMG abnormalities in our patients (45% ) is lower than that cited in other studies on lumbosacral radiculopathy (70% to 80% ),18-20 but it is similar to the 51% rate described by Tonzola et al. 21 In Eisen et al,7 the overall inci¬ dence of EMG abnormalities was higher than in this study (21[75%] of 28). However, of their 36 patients, only seven had cervical disk disease, the rest having lumbosacral root pathology or multisegmental disease; it is therefore difficult to compare.…”

AAEM Minimonograph 32: The electrodiagnostic examination in patients with radiculopathies

“…27,37 F waves have been used for almost two decades in the evaluation of radiculopathies. 29,37,38,119 Initially, it was thought that they would be valuable in detecting lesions involving proximal portions of the peripheral nervous system (PNS), such as radiculopathies, that are inaccessible to the more conventional NCS. In support of this view, high yields were claimed in early reports.…”