Musculoskeletal Key

For every electrodiagnostic (EDX) test performed, one needs to decide if the study is normal or abnormal. That determination often needs to be made in real time as the testing…

Although peripheral nerve anatomy is more or less similar among individuals, in a sizable minority, there are some significant anatomic variations. These are known as anomalous innervations. Several of these…

The electromyographer need not have detailed knowledge of all the electrical and chemical events that occur at a molecular level in order to perform an electrodiagnostic (EDX) study. However, every…

Nerve conduction studies are most often used to assess distal nerve segments, with routine stimulation seldom done above the elbow or knee. Few studies can be easily performed to assess…

After the nerve conduction studies are completed, the electrophysiologic evaluation moves on to the needle electromyography (EMG) examination. Like the nerve conduction studies, each needle EMG study must be individualized…

The use of repetitive nerve stimulation (RNS) dates back to the late 1800s, when Jolly made visual observations of muscle movement that occurred after nerve stimulation. Although his initial studies…

Few routine electrophysiologic tests are available to evaluate the cranial nerves and their proximal segments other than visual and brainstem evoked potentials. However, cranial nerves V (trigeminal) and VII (facial),…

Electrodiagnostic (EDX) studies play a key role in the evaluation of patients with neuromuscular disorders. Among these studies are included nerve conduction studies (NCSs), repetitive nerve stimulation, late responses, blink…