This is a set of tests commonly used to diagnose carpal tunnel syndrome, one of the most common nerve disorders.
It is an outpatient test performed in the Clinical Neurophysiology Department. It is performed by the neurophysiology technician and takes between 20 and 90 minutes
Initially, the nerve is stimulated with a mild electrical current generated by a small electrode placed on the skin. The impulse travels in the nerve through the tunnel to the hand where it is measured. This is the NCS.
Secondly, the activity of the muscle is measured to assess the degree of abnormal function. This is done by the insertion of a small needle into the muscles of the hand and the electrical activity measured with the muscle both at rest and on contraction. This is the EMG.
The results are reviewed by the neurophysiological consultant, who reports back to the referring doctor.