Nerve conduction studies and EMG

Category: Brain, Nerve & Sleep Tests · All brain, nerve & sleep tests

What it is

Nerve conduction studies (NCS) measure how fast and how strongly electrical signals travel along nerves, using surface electrodes and small electrical pulses. EMG (electromyography) uses a fine needle electrode in muscles to listen to their electrical activity, distinguishing nerve problems from muscle problems and pinpointing where a nerve is damaged.

Why it is done

Common uses: carpal tunnel syndrome and other trapped nerves, peripheral neuropathy (for example from diabetes), radiculopathy (pinched nerve roots), facial weakness, and muscle diseases such as myositis or motor neurone disease assessment.

How to prepare

Keep hands and feet warm (cold slows nerves and the team may warm them). Avoid skin creams on the areas to be tested. Tell the team about pacemakers/ICDs, blood thinners (relevant for EMG needles) and any bleeding disorders. Take medicines as usual.

What happens during the procedure

For NCS, small pads are taped to the skin and brief electrical pulses are delivered — felt as taps or tingles, sometimes startling but tolerable. For EMG, a fine needle is inserted into selected muscles while you rest and then contract them gently; you hear the muscle activity through a speaker. The combined appointment takes about 30 to 60 minutes.

Afterwards — recovery & results

You can drive and resume normal activities immediately. EMG needle sites may ache slightly or bruise. Results are analysed and sent to the referring team, usually within a few weeks.

Risks & considerations

Risks are minimal: discomfort during the test, minor bruising from EMG, and very rare infection. Electrical stimulation is used cautiously near cardiac devices, which the team will plan around.

Frequently asked questions

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