What is an electromyography (EMG)?

An EMG is a diagnostic procedure that is used to measure the health of the muscles and the motor neurons (nerve cells) that control muscle movement. The motor neurons send signals to the muscles that tell them to contract. An EMG interprets the signals and turns them into sounds, graphs or numerical values to be assessed. The results can identify muscle dysfunction, nerve dysfunction or problems with transmission of signals from the nerves to the muscles.

Why is an EMG performed?

An EMG may be recommended if certain symptoms appear, including:

  • Certain types of pain in the limbs
  • Muscle cramping or pain
  • Muscle weakness
  • Numbness
  • Tingling

An EMG may also be used to confirm or rule out a condition, such as:

  • Conditions that affect the connection between the muscles and nerves like myasthenia gravis
  • Conditions that affect the motor neurons in the spinal cord or brain, such as amyotrophic lateral sclerosis (ALS) or polio
  • Muscle disorders, including muscular dystrophy
  • Peripheral nerve disorders (peripheral nerves are the nerves outside the spinal cord) like carpal tunnel syndrome or peripheral neuropathy
  • Problems with the nerve root, such as a herniated disc, sciatica or radiculopathy

What happens during an EMG?

An EMG is a safe procedure that can be performed two ways: with electrodes or with a needle.

During an EMG with electrodes, the electrodes are placed on the skin at different points depending on the symptoms being experienced. Then, the patient is asked to contract (tighten) or rest the muscles at certain times. The electrodes will sometimes transmit small electrical currents that may result in a twinge or spasm that is temporary.

During an EMG with needles, the needles are inserted in various locations depending on symptoms (like the EMG with electrodes). Then, spontaneous electrical activity is assessed in muscles at rest as well as the degree of activity when the muscle is active.

Patients may experience temporary minor bruising where the needle is inserted that should clear within several days.

Come to the Specialists

At IGEA Brain, Spine & Orthopedics, we are experts in diagnosing and treating conditions of the brain, spine and neurovascular system. Our neurologists specialize in administering the EMG tests as part of our dedication to providing complete care to patients.

For more information about EMG or to schedule an appointment with our neurologist or our other specialists, contact us today.

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