EMG

Symptoms like tingling, numbness, and muscle spasms or weakness may be red flags alerting you to a nerve or muscle problem. When diagnosing neuromuscular conditions, the skilled team at Dayton Center for Neurological Disorders (DCND) in Dayton, Ohio, often performs electrodiagnostic studies such as electromyography (EMG) and nerve conduction studies (NCS). If you need electrodiagnostic studies, your primary care provider refers you to DCND, and then the office staff will call you to schedule an appointment.

EMG Q & A

What is an EMG?

An EMG is a diagnostic test Dayton Center for Neurological Disorders uses to measure the electrical activity between nerves and muscles. The test reveals information about the extent and location of injured nerves and muscles.

When would I need an EMG?

Your provider may recommend an EMG to determine the cause of symptoms such as:

Numbness
Decreased sensation
Tingling (feeling of pins and needles)
Burning sensation
Radiating pain
Muscle spasms
Muscle weakness

You may also have trouble with everyday activities like walking, holding objects, or buttoning clothes.

What neurological conditions does EMG detect?

An EMG may diagnose numerous muscles and nerve conditions, including:

Motor problems (involuntary muscle twitching, stiffness, or weakness)
Carpal tunnel syndrome (pinched nerve in your wrist)
Peripheral neuropathy (damaged nerves throughout your body)
Radiculopathy (pinched nerve in your spine)
Myositis (muscle inflammation and weakness)
Muscular dystrophy (group of diseases causing progressive muscle weakness)
Myasthenia gravis (autoimmune disease causing weakness in skeletal muscles)
Amyotrophic lateral sclerosis or ALS (progressive disease affecting nerves in your brain and spinal cord)

These are only a few examples of conditions most often diagnosed during an EMG.

What should I expect during an EMG?

Your neurologist may perform a second test, a nerve conduction study (NCS), at the same time as your EMG:

EMG procedure

What's an EMG? - Bing video

After locating the muscle being studied, your provider inserts very fine (thin) needles into the muscle. Once the needles are in place, your provider asks you to contract (tighten) and relax your muscles.

The needles hold tiny electrodes that pick up normal and abnormal nerve signals associated with your muscle movements.

NCS procedure

The nerve conduction study, also called a nerve conduction velocity (NCV) test, shows how fast an electrical signal travels along a specific nerve. Your provider places several electrodes on your skin above the nerve.

Then they send a mild electrical impulse into one end of the nerve, triggering a nerve signal that travels through the nerve. Each electrode along the nerve’s path picks up the electrical activity, providing information about the speed and strength of the signal along the nerve.

If you need an EMG and/or NCS test and you’re not a patient, your primary care doctor refers you to Dayton Center for Neurological Disorders. After you’re referred, the office will call you back to set up an appointment for your electrodiagnostic procedures.