These tests are requested when there is a suspicion that one or more of the nerves in your arms or legs is being affected by either compression, or a generalised inflammatory condition of the nerves called a neuropathy. The commonest reason we ask for these tests is carpal tunnel syndrome, or ulnar nerve compression. Occasionally they can help us further pinpoint the source of your pain if an MRI scan has not shown an abnormality that closely fits in with your symptoms.
An example of this is if an MRI scan of the neck shows multiple nerves compressed, and the symptoms do not help localise the particular nerve involved. An EMG study can help pinpoint which nerve is most likely to be involved
The tests involve coming to hospital for an outpatient test performed by a neurology consultant who specialises in electrical investigations of the nerves and brain called a neurophysiologist. Gentle electrical stimulation of the nerves via the skin will be recorded in the fingers, and occassionally the electrical signals from some muscles will be recorded using a fine needle.
Following these tests I will be sent a report and I will contact you and your GP as soon as possible with the results by phone or letter