What is EMG/NCS?
There are two parts to a comprehensive electrodiagnosis workup: 1. Electromyography (EMG) – refers to direct examination of skeletal muscles using needle a small needle electrode. This is to look at the stability of muscle membrane, denervation/injury potentials, the muscle unit action potential, and the recruitment pattern of the muscles. (Translation: to see if a muscle is irritable, crying for help, neuropathic-appearing, myopathic-appearing, or weak). 2. Nerve Conduction Study (NCS) – refers to examination of peripheral nerves function through electrical stimulation & depolarization. The purpose of NCS is to diagnose the presence of diffuse or focal lesions of peripheral nerves. (Translation: to see if a nerve is conducting its electric signals well.) When to order EMG? 1. Radiculopathy workup – In Acute Radiculopathy >3 days <3 weeks, H-Reflex (NCS version of ankle jerk) can be helpful in diagnosing a S1 radiculopathy, when compared side-to-side. Otherwise, denervation/injury pote
