Magnetic stimulation in cervical radiculopathy and health controls.

Magnetic stimulation was performed in 15 cases of unilateral cervical radiculopathy and 16 age-matched healthy controls. Among the muscle potentials which have acute slope and high amplitude, the difference between the minimal and the maximal latency in the same muscle was defined as variability. In the healthy control group, the variability of the muscle potentials evoked by head magnetic stimulation was approximately 2 ms. In cervical radiculopathy, the muscle potential latencies in head magnetic stimulation were normal except for one case because of the wide normal range. However, the interside difference of the muscle potential latency in head magnetic stimulation was significantly greater in the cervical radiculopathy group than in the healthy control group. This suggests that the interside difference of the muscle potential latency is more sensitive than the muscle potential latency in head magnetic stimulation in unilateral radiculopathy.