An expert guide: Nerve conduction studies and EMG

Highly respected consultant neurophysiologist Dr Taimour Alam sheds light on nerve conduction and EMG studies in this informative guide for patients, including when tests of this type are indicated and their role in diagnosing nerve problems. The leading specialist also offers expert guidance and reassurance on what patients can expect from the procedures themselves.

What is a nerve conduction study used to diagnose?

Nerve conduction studies are used to uncover any issues with the peripheral nerves. These are the nerves that travel outside of the brain and spinal cord but are part of the entire system that controls movement and carries sensory information to the brain. We use the test to find out where the problem might be and what type of problem it is. Often we can also help to determine how likely things are to recover.

How is a nerve conduction study performed?

Stickers (surface electrodes) are placed over the relevant nerves or muscles and electrical pulses are used to stimulate the nerve and take recordings of the responses. With some parts of the test you will feel some twitching of the muscles.

What is EMG and will I need it?

EMG stands for electromyography. This means taking recordings from the muscles, mostly using a very thin wire electrode that is inserted into the muscle itself.

The question of adding the EMG part of the test along with the selection of muscles to be tested depends on the clinical problem and how we can best answer it. It will be discussed before starting the test. Generally this is kept to the minimum needed to adequately assess the problem.

How long does it take?

This can vary depending on the complexity of the problem but for most patients twenty to thirty minutes is required to complete the consultation and test.

Is it a painful process?

Nerve conduction studies are not usually painful but often feel strange. Most people report it feeling ‘weird’. If you have used a TENS machine in the past, then you will be somewhat familiar with the feeling.

EMG can be slightly uncomfortable as we are inserting the wire electrode into the muscle itself, often in different locations. However the wire is very thin and this is generally very tolerable for most people.

Are there any side effects?

There are no known significant side effects from either nerve conduction studies or EMG. If you are on blood-thinner medication, please mention this at the start as there is a small risk of bleeding and a discussion can be had regarding the benefits vs risks of EMG. After the EMG component, the muscles which have been examined can feel slightly sore for up to twenty-four hours but this settles completely.

Is there anything I can do to prepare for my nerve conduction study?

There is nothing specific you need to do to prepare for the test. The limbs being tested need to be warm so it is often worth wearing gloves before arriving for the test on a cold day, if the hands are the problem. It is also recommended to wear loose fitting clothes so we can get to the areas needed.

If you wish to schedule a consultation with Dr Alam, you can do so by visiting his Top Doctors profile.