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For a more accurate diagnosis

Electromyogram (EMG)

The electromyogram (EMG) measures the electrical activity of muscles at rest and during contraction. Nerve conduction studies measure how well and how fast the nerves can send electrical signals. The nerves control the muscles by sending electrical signals (impulses) and these impulses make the muscles react in specific ways. In the presence of muscular and nervous disorders, the muscles react abnormally.

The analysis of the electrical activity of the muscles and the nerves is useful for diagnosing muscle diseases (muscular dystrophy) or nerve damage (amyotrophic lateral sclerosis, peripheral neuropathies). EMG and nerve conduction studies are often done together.

EMG is indicated when a disease of the muscle, of the nerve or of the junction between nerve and muscle (neuromuscular junction) is suspected. EMG is also indicated in cases of paralysis or weakness (carpal tunnel syndrome, etc.).

Nerve conduction studies are also indicated when a disease of the peripheral nervous system (multiple sclerosis, Guillain Barré syndrome, etc.) is suspected.

Some drugs can alter the results of the EMG (muscle relaxants, anticholinergics, etc.).

The test, which takes approximately 30 minutes, is performed by a doctor who specializes in Neurology. A slight discomfort may be felt during the insertion of the needle into the muscle. Otherwise, the examination is generally well tolerated and you can resume your usual activities immediately after.

If you have a prescription for an electromyogram, you can call 514 747-8185 to book an appointment. We will quickly forward your results to your physician.

The examination, in two parts

  • study of nerve conduction

    the study of nerve conduction of sensory nerves (responsible for sensibility) and of motor nerves (responsible for muscle contraction), which is done by stimulating a nerve at different spots on its trajectory by electric impulses of low intensity

  • electromyography

    Electromyography, which uses a needle electrode inserted into the muscle. This examination consists of recording the spontaneous electrical activity of a muscle, first at rest and then during a voluntary movement. The electrode is placed on the surface of the muscle that is studied