Electromyogram (EMG) and Nerve Conduction Studies
An EMG is very safe. You may
get some small bruises or swelling at some of the needle sites. The needles are
sterile, so there is very little chance of getting an infection.
There is no chance of problems with nerve conduction studies. Nothing is
put into your skin, so there is no chance of infection. The voltage of
electrical pulses is not high enough to cause an injury.
Your doctor may be able to tell you
about some of the results of your nerve studies right after the tests. A full report may take 2 to 3
Electromyogram (EMG) and nerve conduction studies
The EMG recording shows no electrical activity when the
muscle is at rest. There is a smooth, wavy line on the recording with each
The nerve conduction studies show that the nerves
send electrical impulses to the muscles or along the sensory nerves at
normal speeds, or conduction velocities. Sensory nerves allow the brain to feel
pain, touch, temperature, and vibration. Different nerves have different normal
conduction velocities. Nerve conduction velocities generally get slower as a
person gets older.
Electrical activity in a muscle at rest shows that there
may be a problem with the nerve supply to the muscle. Abnormal wave lines when
a muscle contracts may mean a muscle or nerve problem, such as
a herniated disc, amyotrophic lateral sclerosis (ALS),
In nerve conduction studies, the speed of nerve impulses is slower than what is normal for that nerve. Slower
speeds may be caused by injury to a nerve or group of nerves. Nerve
conduction velocities generally get slower as a person gets older.
The results from EMG and nerve conduction studies are used
along with your medical history, symptoms, physical and neurological exams, and
the results of other tests to help your doctor find out what the problem is or
see how a disease is changing.
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
- Taking medicines, such as muscle relaxants and
- Having bleeding, swelling, or too much fat under the skin at the
site of the nerves or muscles being tested.
- Not being able to do what is asked during the test.