EMG needle causes severer pain in the end-plate region compared to the silent site of the muscle

We investigated the severity and the quality of pain in the end-plate and t he electrically silent site during electromyography by self-assessment. In 42 muscles of 30 patients, the mean pain score was 52.0 +/- 5.3 of 100 for the end-plate region, and it was 27.7 +/- 4.8 for the silent site. The comm onest type of pain was pricking both in the end-plate region and the silent site (19 and 31%, respectively). We suggest two hypotheses for the differe nce. The pain fibers may be more densely situated in the end-plate, or musc le fiber contraction precipitated by needle irritation may also cause irrit ation of pain fibers. Copyright (C) 2000 S. Karger AG, Basel.