An electromyogram (EMG) measures the electrical activity of muscles at rest and during contraction. Nerve conduction studies measure how well and how fast the nerves can send electrical signals from the spinal cord to the muscles.

An EMG is done to find diseases that damage muscle tissue, nerves, or the junctions between nerve and muscle.

A nerve conduction study is done to find damage to the peripheral nervous system, which includes all the nerves that lead away from the brain and spinal cord and the smaller nerves that branch out from those nerves.

Tell your doctor if you:

• Are taking any medicines. Certain medicines that affect the nervous system can change Electromyogram (EMG) results. You may need to stop taking these medicines 3 to 6 days before the test.
• Have had bleeding problems or take blood thinners, such as warfarin or heparin. If you take blood thinners, your doctor will tell you when to stop taking them before the test.
• Have a pacemaker.
• Do not smoke for 3 hours before the test.
• Do not eat or drink foods that contain caffeine (such as coffee, tea, cola, and chocolate) for 2 to 3 hours before the test.
• Wear loose-fitting clothing so your muscles and nerves can be tested.
• Do not use body lotions prior to exam.