Electromyography (EMG)
Electromyography (EMG) measures muscle response or electrical activity in response to a nerve’s stimulation of the muscle. The test is used to help detect neuromuscular abnormalities. Nerve cells are known as motor neurons and they transmit electrical signals that cause muscles to contract and relax. EMG results can help the doctor diagnose
- Carpal tunnel syndrome
- A pinched nerve
- Radiculopathy
- Sciatica
- Neuropathies
- Muscle diseases
- Muscular dystrophy
- Lou Gehrig’s disease
- Myasthenia gravis.
Preparation and procedure
All medications can be taken as normal. Wear loose fitting clothing. During the test, one or more small needles (also called electrodes) are inserted through the skin into the muscle. The nerve conduction part of the test usually takes longer than the needle exam because one needs to make calculations and measurements during it. On average, if one extremity is studied, the nerve conductions take anywhere between 15 and 30 minutes. The needle exam for one extremity usually takes 15 to 20 minutes.
