Electrodiagnostic testing assesses the health of muscles and the motor neuron nerve cells that control them. Motor neurons are responsible for transmitting signals from the spinal cord to muscles, enabling muscle contraction.
Electrodiagnostic testing results can reveal nerve dysfunction, muscle dysfunction, or problems with nerve-to-muscle signal transmission.
This procedure usually involves two different tests:
- A nerve conduction study (NCS), which is also known as a nerve conduction velocity (NCV) test
- An electromyography (EMG) diagnostic procedure
The length of electrodiagnostic testing can range from 1 to 3 hours, based on the underlying clinical problem.
Nerve Conduction Study Test Procedure
In a nerve conduction study, several flat metal disc electrodes are taped to your skin above the nerve. A doctor stimulates a nerve with brief electric pulses. This test is done in two or more places along the nerve’s path.
Data is recorded that shows the speed at which the electrical impulse travels through the nerve. If that speed is slower than typical readings, it suggests possible nerve damage.