Comparison of sensitivities of macroEMG and concentric needle EMG in L4 radiculopathy

Abstract. The purpose of this study was to compare the sensitivitiesof macro EMG (mEMG) and concentric needle EMG (cnEMG) in showingabnormality in L4 radiculopathy. We evaluated 23 patients withclinically and radiologically proven L4 root lesions. Amongthese patients, 21 (92%) had cnEMG abnormalities. Out of 21patients with cnEMG abnormality, 3 (14%) had fibrillations andpositive sharp waves, 8 (38%) had interference patternabnormality and all of them had motor unit potential (MUP)abnormality on quantitative MUP analysis. Seventeen patients(74%) had mEMG abnormality. Diagnostic yield of cnEMG is higherthan mEMG in L4 radiculopathy. mEMG may not contribute much tothe diagnosis of lumbar radiculopathy.Presented in part at the 18th Annual Meeting of theTurkish Clinical Neurophysiology EEG-EMG Society, June 2002,Turkey.