Magnetic stimulation of peripheral nerves. Comparison of magnetic stimulation with electrical stimulation.

We measured total peripheral motor conduction time by two different methods, magnetic stimulation and electrical stimulation, to reveal which is better in determining actual peripheral motor conduction time. In the upper extremities, the difference between magnetic stimulation and electrical stimulation was within a mean time of 1.39 +/- 0.8 msec, while that in the lower extremities was 2.3 +/- 1.1 msec. In any 4 extremities, total peripheral motor conduction time obtained by magnetic stimulation was significantly shorter than that measured by electrical stimulation employing conventional F-wave response. We conclude that stimulus sites 8.8 +/- 5.1 cm distal to spinal motoneurons in the upper extremities, and 10.5 +/- 5.3 cm distal in the lower extremities were stimulated by magnetic stimulation of the peripheral nerves. Electrical stimulation employing conventional F-wave measurement is superior to magnetic stimulation for actual total peripheral nerve conduction study.