EMG Test

Electromyography (EMG) is a diagnostic test that helps detect neuromuscular abnormalities by measuring electrical activity in the muscles.

What is an EMG Test?

During an EMG test, a very thin needle (electrode) will be inserted through the skin and into the muscle. Once the electrode is in place, the patient will be asked to either contract their muscles or keep their muscles relaxed. The electrode will detect electrical activity and results will be displayed on a nearby monitor (oscilloscope).

A nerve conduction velocity (NCV) test is often performed at the same time as an EMG. An NCV helps to differentiate a nerve disorder from a muscle disorder.

EMG Testing at Brigham and Women’s Hospital

The Brigham and Women’s Hospital (BWH) Division of Neuromuscular Disease and Electromyography (EMG) provides comprehensive diagnostic evaluation, consultation, and management of all neuromuscular disorders, including motor neuron disease (ALS), peripheral neuropathies, myopathies, muscular dystrophy, and myasthenia gravis.

Currently, we offer comprehensive neuromuscular services, including EMG, at the main BWH campus in Boston and EMG and other diagnostic services at Brigham and Women's/Massachusetts General Health Care Center.

Specialists at the Division of Neuromuscular Disease and Electromyography use EMG tests to diagnose a wide variety of neuromuscular diseases, motor problems, nerve injuries, or degenerative conditions, such as:

  • Amyotrophic lateral sclerosis (ALS) – progressive degeneration of nerves in the spinal cord and brain that may ultimately lead to difficulty breathing, difficulty swallowing, and paralysis.
  • Carpal tunnel syndrome – compression of a nerve in the wrist that may lead to pain, weakness, and numbness in the hands.
  • Cervical spondylosis (arthritis of the neck) – degeneration of the cervical spine that causes compression of the spinal cord and nerve roots.
  • Guillain-Barré syndrome – a potentially life-threatening disorder that causes the body’s immune system to attack the peripheral nervous system.
  • Lambert-Eaton syndrome – causes the immune system to attack the neuromuscular junctions (connections between muscles and nerves), leading to impaired muscle control.
  • Muscular dystrophy - characterized by weakness and breakdown of muscle tissue, with or without deterioration of nerve tissue.
  • Myasthenia gravis – autoimmune disorder that affects the body’s voluntary muscles, especially the eyes, mouth, throat, and limbs.
  • Peripheral neuropathy – damage to the peripheral nervous system, leading to symptoms ranging from tingling or numbness in a certain body part to more serious effects, such as burning pain or paralysis.
  • Polymyositis – causes irritation and inflammation of skeletal muscles.
  • Radial nerve dysfunction – damage to one or more nerves in the arm, which can cause pain, numbness, and movement difficulties in the forearm, wrist, and hand.
  • Sciatica nerve dysfunction – a pain that originates along the sciatic nerve, which extends from the back of the pelvis down to the back of the thigh.

How do you prepare for an EMG test?

Typically, not a lot of preparation is necessary for an EMG.

  • Avoid using any creams or lotions on the day of the test.
  • Fasting is usually not required, but, in some cases, patients will be asked to refrain from smoking cigarettes or drinking caffeinated beverages for up to two to three hours before the test.
  • Notify your physician if you have a pacemaker.
  • Tell your physician about all the medications and herbal supplements you are taking.
  • Dress in clothing that enables easy access to the area to be tested.

Neurology at Brigham and Women’s Hospital

The Brigham and Women’s Hospital Department of Neurology comprises a diverse yet integrated array of specialized clinical services, including inpatient and outpatient evaluation and management, second opinions for complex cases, diagnostic testing, and care for the most critically ill. This collaborative approach enables our team to provide patients with all the care they need in one location, providing a greater measure of safety, convenience, and satisfaction.

Patient- and Family-focused Care
BWH has long been committed to not only the care of our patients but also the many other needs that they and their families have. This philosophy of patient- and family-focused care – involving systems and services that emphasize healing in a comfortable, relaxed environment – is a guiding force behind the care we provide at the Department of Neurology.

Quality of Patient Care
Brigham and Women’s Hospital is committed to providing all of our patients with the safest, highest-quality, most-satisfying care possible and following established protocols that have been shown to improve patient outcomes. Our inpatient satisfaction survey, sent to patients to assess their total care experience, helps us to monitor what we are doing well and what areas may need improvement. We pride ourselves in the quality of patient care we provide and how we compare with other hospitals.

Brigham and Women’s Hospital Neurology Team

The Department’s multidisciplinary staff of more than 65 clinical faculty and over 350 department members strives to provide patient-focused, world-class medical care for the entire spectrum of neurological diseases. We have a strong focus on developing new treatments and cures for neurologic diseases, and we offer a variety of teaching programs that train the next generation of neurology professionals.

Contact Us

If you believe you should have an evaluation and would like to schedule an appointment with one of our neurology experts, call 1-800-294-9999 to speak to one of our knowledgeable coordinators who can help to connect you to the doctor that best meets your needs, or fill out an online appointment request form.

Find a DoctorFind an expert Neurologist for innovative neurologic treatment and compassionate care.

Find an expert Neurologist for innovative neurologic treatment and compassionate care.

Quality and SafetyLearn how quality and patient safety are at the core of Brigham and Women's mission and vision.

Learn how quality and patient safety are at the core of Brigham and Women's mission and vision. 

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Learn more about how U.S. News & World Report ranks Brigham and Women’s Hospital.

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