Fig. 1
From: A case of spinal nerve neurotoxicity with ropivacaine after combined spinal and epidural anesthesia
F wave frequency and needle EMG of the bilateral tibia anterior muscle recorded 7 days after the operation. F wave (upper) was recorded in 26 trials of supramaximal stimulation delivered at 1/s before a brief 20-Hz stimulation. There is no evoked F wave in the left tibial anterior muscle. Needle EMG (lower) shows no contraction and no action potential were recorded in the left tibial anterior muscle as well as impaired contraction in the right tibial anterior muscle. Lt tibia ant, left tibial anterior muscle; Rt tibia ant, right tibial anterior muscle