Objectives: To investigate the effects of topical anesthetic ointment (lidocaine 2.5%⁢prilocaine 2.5%) to the pain during electromyographic examination

Method
Thirty-two adults without known neurological disorders were studied. The needle Electromyography (EMG) of flexor carpi radialis (FCR) muscle and the motor and sensory conduction studies of median nerve were performed after the application of topical anesthetic ointment in one upper extremity and compared to the other side upper extremity without anesthesia. The intensity of pain was assessed with the Visual Analog Scale (VAS) and the characteristics of pain was evaluated with the modified short-form McGill pain questionnaire.

Results
The VAS score of the needle EMG of FCR muscle in the anesthetized side was significantly lower to that of the non-anesthetized side (P＜0.01). And the characteristics of pain were shooting (10 cases, 31.3%), or throbbing (6 cases, 18.8%) in the anesthetized side and dull (13 cases, 40.6%), or numb (7 cases, 21.9%) in the non-anesthetized side. The VAS scores of the sensory and motor nerve conduction study of median nerve were not significantly different in both sides.

Conclusion
The application of topical anesthetic ointment decreases the intensity and changes the characteristics of pain during the needle EMG.