Routine Clinical Electromyography

Nerve conduction studies and needle EMG represent the two essential parts of the clinical EMG study. In almost all patients, both studies need to be completed before a final conclusion is made. This chapter outlines the basic concepts of nerve conduction studies including stimulations, recordings, variables and sources of errors. This is followed by detailed discussions of basic pathophysiological changes that accompany peripheral nerve disorders. The chapter then covers the normal needle EMG findings including normal insertional activity, motor unit action potential morphology and recruitment. This is followed by details on abnormal spontaneous activity findings and changes in motor unit action potential morphology and recruitment seen on needle EMG with peripheral nerve and muscle disorders.