Peripheral nerve stimulator performance: the influence of output polarity and electrode placement.

The median as well as the ulnar nerve may be used effectively in the evaluation of neuromuscular blockade with the peripheral nerve stimulator. Both ulnar and median nerve stimulation produce flexion of the fingers. For maximum neural stimulation either during the routine use of the peripheral nerve stimulator or when it is used as an aid to peripheral nerve block, the negative pole should be attached to the exploring needle or over the nerve to be stimulated.