(HealthDay)—For patients with lumbosacral disc herniation, neurophysiological tests together with neuroimaging and clinical examination allow for accurate preoperative assessment of injury, according to a study published in the Oct. 1 issue of Spine.

Magdalena Wojtysiak, M.D., Ph.D., from the Poznán University of Medical Sciences in Poland, and colleagues conducted a comparative analysis of preoperative and postoperative electromyography, electroneurography, F-waves, H-reflex, and motor evoked potentials (MEP) for 23 patients with confirmed disc-root conflict at lumbosacral spine. The patients also underwent clinical assessment, including examination of sensory perception for L5 to S1 dermatomes, muscle strength, deep tendon reflexes, pain intensity, and straight leg-raising test.

The researchers found that for evaluation of L5 to S1 roots injury, the sensitivity of electromyography at rest was 22 to 63 percent and of MEP examination was 31 to 56 percent; the corresponding specificities were 71 to 83 percent and 57 to 86 percent. For evaluation of S1 root injury, H-reflex sensitivity and specificity were 56 and 67 percent, respectively. For L5 and S1 root levels, there were significant improvements of root latency parameter in postoperative versus preoperative MEP studies.

"The analysis of the results from neurophysiological tests together with and allow for a precise preoperative indication of the lumbosacral roots and accurate postoperative evaluation of patients experiencing sciatica," the authors write.

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Journal information: Spine