Clinical usefulness of electrodiagnostic study to predict surgical outcomes in lumbosacral disc herniation or spinal stenosis.

Abstract

Although surgeries have been performed for the treatment of lumbar disc herniation (LDH) or lumbar spinal stenosis (LSS), not all patients who undergo surgery are satisfied with the outcome. Electrodiagnostic study (EDX) can assess the physiological functions of nerve roots with higher specificity and relate better with clinical manifestations. The purpose of this study was to examine how EDX can predict surgical outcomes in patients with LDH and LSS and to compare the predicted values of EDX with other clinical factors and MRI findings. Patients diagnosed with LDH or LSS without neurological deficits, who underwent EDX before lumbar surgery, were selected and analyzed. Patients were divided into groups of successful and unsuccessful surgical outcomes according to a modified MacNab classification. We obtained pre-operative clinical data, radiological results, and EDX results. Using EDX, radiculopathy was found in 236 patients (52.7%) in the study population. Radiculopathy on EDX was significantly related only to unsuccessful surgical outcomes. The association of spondylolisthesis showed the trends towards unsuccessful surgical outcome, despite statistical insignificance. EDX detected functional abnormalities of nerve roots that did not show clinical manifestation and did not appear compressed on MRI. These abnormalities are important predictive factors for surgical outcomes in patients with LDH or LSS. Therefore, pre-operative EDX is a clinically useful method to predict surgical prognosis.