Nerve tests
If your blood test result is normal but the doctor isn’t convinced, they may recommend an electrical test of your nerves and muscles. These tests, known as electromyography, involve putting small needles into your muscles to evaluate the electrical activity in them. The needles are usually inserted around the eyes, in the forehead or possibly in the arms.
The electrical recordings can show whether the signals sent from the nerves to the muscles are being disrupted, which may be a sign of myasthenia gravis.