Diagnostic value of electrophysiological tests in patients with sciatica.

OBJECTIVES

To assess the diagnostic value of electrophysiological tests in patients with sciatica.

MATERIALS AND

METHODS

The diagnostic value of electrophysiological tests were evaluated in 25 patients with monoradicular sciatica. The electrophysiological study included dermatomal somatosensory evoked potentials, electromyography, F-wave latencies, H-reflexes and motor and sensory nerve conduction determinations. The results of the electrophysiological examinations were evaluated blindly, and the test results were analysed separately by a receiver operating characteristic (ROC) analysis. Furthermore, the 5 modalities were evaluated jointly and analysed by a decision-analytic regret function.

RESULTS

A high predictive value was found for the H-reflex examination, but low for the other modalities. When the 5 modalities were evaluated jointly, a non-significant decrease in expected regret from the pre-test situation of 0.96 to a value of 0.93 in post-test situation was revealed.

CONCLUSION

Electrophysiological testing is not sufficient as stand-alone examination in patients with sciatica.