Electrodiagnostic medicine is the study of diseases of nerves and muscles.
Your doctor has recommended an EMG test to see if your muscles and nerves
are working right. You can have problems in only one part of your body
or throughout your body. The results of the tests will help your doctor
decide what is wrong and how it can be treated.
Who does the testing?
The American Association of Neuromuscular & Electrodiagnostic Medicine’s
policy is that an appropriately trained doctor should do all needle EMG
testing. A trained assistant or technologist under a doctor’s supervision
can do nerve conduction studies. Our physicians are all neurologists
with specialty training in performing EMG and Nerve Conduction Testing.
Why am I being sent to the EMG Lab for tests?
You are being sent to the electromyography (EMG) lab because you have
numbness, tingling, pain, weakness, or muscle cramping. Some of the tests
that the EMG doctor may use to diagnose your symptoms are nerve conduction
studies (NCSs), needle EMG, and evoked potentials. The EMG doctor will
examine you to decide which tests to do.
Nerve Conduction Studies
NCSs show how well the body’s electrical signals are traveling
to a nerve. This is done by applying small electrical shocks to the nerve
and recording how the nerve works. These shocks cause a quick, mild,
tingling feeling. The doctor may test several nerves.
Needle EMG (Electromyography)
For this part of the test, a small, thin needle is put in several muscles
to see if there are any problems. A new needle is used for each patient
and it is thrown away after the test. There may be a small amount of
pain when the needle is put in. The doctor tests only the muscles necessary
to decide what is wrong. The doctor will look at and listen to the electrical
signals that travel from the needle to the EMG machine. The doctor then
uses his medical knowledge to figure out what could be causing your problem.
The tests usually take 20 to 90 minutes. You can do any of your normal
activities, like eating, driving, and exercising, before the tests. There
are no lasting side effects. You can also do your normal activities after
How should I prepare for the tests?
Tell the EMG doctor if you are taking aspirin, blood thinners (like
Coumadin®), have a pacemaker, or have hemophilia. Take a bath or
shower to remove oil from your skin. Do not use body lotion on the day
of the test. If you have myasthenia gravis, ask your EMG doctor if you
should take any medications before the test.
When will I know the test results?
The EMG doctor will discuss your test results with you or send them
to your regular doctor. After the exam, check with the doctor who sent
you to the lab for the next step in your care.
Diseases for which we will frequently do EMG/NCS testing:
• Amyotrophic Lateral Sclerosis (ALS)
• Autonomic Disorders Hereditary Motor Sensory Neuropathy
• Becker Muscular Dystrophy
• Bell's Palsy
• Brachial Plexopathy
• Carpal Tunnel Syndrome
• Chronic Inflammatory Demyelinating
• Congenital Myasthenia Gravis
• Diabetic Neuropathy
• Duchenne Muscular Dystrophy (DMD)
• Guillain-Barré Syndrome
• Facioscapulohumeral Muscular Dystrophy (FSH)
• Inclusion Body Myositis
• Kugelberg-Welander Disease
• Lambert-Eaton Myasthenic Syndrome
• Limb Girdle Muscular Dystrophy
• Low Back Pain
• Mononeuropathy Multiplex
• Motor Neuron Disease
• Multifocal Motor Neuropathy
• Muscular Dystrophy
• Myasthenia Gravis
• Myotonia Congenita
• Myotonic Dystrophy
• Neck Pain
• Pinched Nerve
• Polyradiculopathy (AIDP)
• Posterior Interosseous Neuropathy
• Post-polio Syndrome
• Radial Nerve Palsy
• Spinal Muscular Atrophy
• Tarsal Tunnel Syndrome
• Thoracic Outlet Syndrome
• Ulnar Neuropathy
• Werdnig-Hoffman Disease