An EMG checks the electrical activity in your muscles and nerves. It helps your team confirm myositis, see how active it is, and rule out other causes of weakness.
You are awake the whole time, no freezing or sedation is needed, and you can drive yourself home afterward.
An EMG (electromyography) is usually done together with nerve conduction studies, by a neurologist. It has two parts. In the nerve conduction study, small sticky pads are placed on your skin and brief, gentle electrical pulses are sent through them to measure how well your nerves carry signals. In the EMG part, a very thin needle electrode is placed into a few muscles to record their electrical activity, first while the muscle is relaxed and then while you gently tighten it.
The test shows whether your weakness is coming from the muscle, the nerve, or both. In myositis, it can reveal a pattern that points to muscle inflammation, help confirm the diagnosis, and give a sense of how active the disease is. It also helps your team choose the best muscle to sample if a biopsy is needed, and it helps rule out other conditions that can look like myositis.
Most people find the test uncomfortable rather than painful, and the discomfort is brief. The muscles tested may feel a little sore or bruised for a day or two. You can return to your normal activities right away, including driving.
An EMG is very safe. The most common effects are minor soreness or a small bruise where the needle was placed. Bleeding and infection are rare. Telling the team about any blood thinners lets them take extra care.
The neurologist reviews the recordings and sends a report to your Centre team, who will go over what the test means for you at your next visit.
This guide is for learning, not medical advice. Your team will explain your own test, and every person’s situation is a little different. Always follow the instructions you are given.