Premotor potential study in carpal tunnel syndrome.

INTRODUCTION

Premotor potentials (PMPs) precede compound muscle action potentials evoked from the second lumbrical muscle after median nerve stimulation. Although PMP has been identified as a median sensory nerve action potential, few reports have documented the significance of PMP parameters for diagnosing carpal tunnel syndrome (CTS).

METHODS

We investigated the relationships between PMP parameters and results of 6 standard median nerve conduction studies in 74 CTS hands.

RESULTS

Significant correlations were noted in all comparisons. PMP conduction velocity was strongly correlated with the sensory conduction velocity between wrist and digit 2 (r(2) = 0.91). Moreover, PMP parameters were significantly correlated with neurophysiological severity of CTS.

CONCLUSION

Measuring PMP parameters with a second lumbrical-interosseous study may be useful for diagnosing CTS.