Electromyography (EMG) and Nerve Conduction Studies

Neurophysiology is the study of brain, spinal cord nerve and muscle function. With our tests we record and interpret electrical signals from the body to help diagnose disorders.

What are Electromyography and Nerve Conduction Studies?

Electromyography (EMG) records electrical activity from your muscles and Nerve Conduction Studies (NCS) from your nerves.

What do I need to know before I come to the test?

• We will need to know if you have a pacemaker or if you are taking any blood thinning medication.
• If you are taking oral anticoagulant medication (i.e. warfarin, rivaroxaban, apixaban) we will need to know your latest blood results (INR values).
• If you are taking the medication “Pyridostigmine” and you come for a Single Fiber EMG test (SFEMG), the medication should be stopped 12 hours before your test if it is safe to do so (take advice from your doctor).
• If you have any queries, please ask the doctor that referred you for the test.

What do I need to do to prepare for the test?

• Before you come for the test you can have your meals at normal times and continue taking any current medication that you are on unless you have been advised otherwise by your clinician.
• Bring a list of your medication and any allergies with you.
• Wear loose fitting clothing so that your legs, back, arms and shoulders can be easily reached. The clinician may ask you to remove some jewellery as it might interfere with the test.

Important: On the morning of your test please do not use body creams/lotions on the arms and legs unless this is to treat a skin condition, as this may affect the test and results.

What will happen during my test?

The test will be carried out by a Doctor or a specialist in nerves called a Clinical Physiologist.

During the appointment we might need to do one or both of the following:

• If you are having an Electromyography test, this involves inserting a fine needle into the muscles and you may feel a little pain.
• If you are having Nerve Conduction Studies, we will apply small electrical stimulus to your nerves and record the responses with small stickers and pads that will be attached to your skin. This will cause a tingling sensation and some twitching of the muscles of your hand or foot. Most patients do not find this test painful.

You can bring someone with you to your appointment.

What will happen after my test?

The Nerve Condition Studies have no after-effects but the Electromyography may leave some bruising or swelling and your muscles may feel a little sore for a few hours afterwards. There are no long-lasting after-affects from either of these tests and once completed you can return to normal activities.

It is extremely uncommon to experience a complication from the Electromyography, but should you experience pain where the needle was inserted or you have swelling, tenderness, hot/redness or pus, seek advice from your GP. In the case of intense pain, especially if the muscle is stretched and weak, seek immediate medical advice.

The results of the tests will take a few weeks to be analysed by the physiologist and consultant. You hospital clinician will contact you if something of concern is detected by the test, otherwise your hospital clinician or referring doctor will discuss the results with you at the next appointment.

Your GP will receive a copy of the results and you may ask them for a copy, if you wish. 

If you need further information about this or similar neurophysiological tests, please visit:

The British Society for Clinical Neurophysiology (bscn.org.uk)

Contacts

Neurology (Neurophysiology Department)

020 8934 6156 (Option 3)