Diagnostic value of history, physical examination and needle electromyography in diagnosing lumbosacral radiculopathy

To examine the diagnostic value of history, physical examination and needle EMG in predicting nerve root compression on MRI in patients with clinical suspicion of lumbosacral radicular syndrome (LSRS). Subjects comprised 202 consecutive patients from January 2006 to March 2007 with suspicion of LSRS referred by general practitioners. Clinical evaluation consisted of history, physical examination, EMG and MRI. Bivariate and multiple logistic regression analyses were used to calculate the diagnostic value of each test item compared to radiological nerve root compression. 95 patients (47%) had radiological nerve root compression. Significant predictors of radiological nerve root compression were dermatomal radiation [odds ratio (OR) 2.1], more pain on coughing, sneezing or straining (OR 2.4), positive straight leg raising (OR 3.0) and ongoing denervation on EMG (OR 4.5). 15 patients (7%) had ongoing denervation on EMG without radiological nerve root compression. In clinical practice, dermatomal radiation, more pain on coughing, sneezing or straining, positive straight leg raising and ongoing denervation on EMG may be used to predict nerve root compression on MRI. EMG may also be of additional value in patient with clinical suspicion of lumbosacral radicular syndrome without nerve root involvement on MRI.