What do my EMG results mean?

Electromyography (EMG) is a diagnostic procedure to assess the health of muscles and the nerve cells that control them (motor neurons). EMG results can reveal nerve dysfunction, muscle dysfunction or problems with nerve-to-muscle signal transmission.

What is a normal EMG result?

Normal Results from an EMG

Normal EMG results will appear as no electrical activity while at rest. It means your muscles are healthy and normal. Your muscles also react normally to stimulation, in a smooth pattern.

What does an abnormal EMG result look like?

Abnormal EMG results can show up in two ways. First, the muscle may show electrical activity at rest. On the other hand, the muscle may show abnormal electrical activity during contraction. This shows up as an abnormal action potential pattern with changes in the size or shape of the wave.

What are normal nerve conduction test results?

NCV tests can measure the speed and strength of nerve signals. Nerve conduction velocity between 50 to 60 meters per second is considered normal. A damaged nerve may send a slower and weaker signal than a healthy one. It is possible to have normal results even if a person has nerve damage.

Can you have a normal EMG and still have nerve damage?

Could it still be neuropathy? You can still have polyneuropathy with a normal EMG nerve conduction study. EMG nerve conduction studies can only assess large fiber polyneuropathy. Small fiber cannot be evaluated by EMG nerve conduction study, but it may be assessed by skin biopsy.

What diseases can an EMG detect?

An EMG can be used to diagnose a wide variety of neuromuscular diseases, motor problems, nerve injuries, or degenerative conditions, such as:

• Amyotrophic lateral sclerosis (ALS)
• Carpal tunnel syndrome.
• Cervical spondylosis.
• Guillain-Barre syndrome.
• Lambert-Eaton syndrome.
• Muscular dystrophy.
• Myasthenia gravis.

Can an EMG detect peripheral neuropathy?

The diagnosis of peripheral neuropathy can be supported by electrodiagnostic testing, which includes nerve conduction studies (NCS) and needle electromyography (EMG). This activity reviews some of the causes of peripheral neuropathy and the corresponding electrodiagnostic findings.

What are signs of nerve damage?

The signs of nerve damage

• Numbness or tingling in the hands and feet.
• Feeling like you're wearing a tight glove or sock.
• Muscle weakness, especially in your arms or legs.
• Regularly dropping objects that you're holding.
• Sharp pains in your hands, arms, legs, or feet.
• A buzzing sensation that feels like a mild electrical shock.

What diseases does a nerve conduction test show?

Nerve conduction studies and EMGs can diagnose a variety of conditions, including:

• Amyotrophic lateral sclerosis (ALS) aka: Lou Gehrig's disease.
• Carpal tunnel syndrome.
• Charcot-Marie-Tooth (CMT) disease.
• Chronic inflammatory polyneuropathy and neuropathy.
• Guillain-Barre syndrome.
• Herniated disc disease.
• Muscular dystrophy.

Does an EMG show muscle damage?

EMG is most often used when a person has symptoms of weakness, pain, or abnormal sensation. It can help tell the difference between muscle weakness caused by the injury of a nerve attached to a muscle, and weakness due to nervous system disorders, such as muscle diseases.

Are EMG results accurate?

EMG/nerve conduction studies had a 74% agreement with final clinical diagnoses and 100% agreement in neurogenic, neuromuscular junction, and normal categories. Muscle biopsies concurred with final diagnoses in 87%, and 100% in myopathic and normal categories.

What does ALS look like on EMG?

The hallmark of ALS on needle EMG is chronic and active loss of LMNs innervating muscles with multiple nerve root innervation and spread within an initial body segment and to other body segments.

What can cause an abnormal EMG?

An abnormal EMG result may be a sign of a muscle or nerve disorder, such as:

• Polymyositis. ...
• Muscular dystrophy. ...
• Myasthenia gravis. ...
• Myotonic (stiff) muscles.
• Damage or disease of the motor nerve, such as can be seen with nerve disease.

Will an EMG show a pinched nerve?

What is an EMG? Electromyography (EMG) is a safe and relatively painless test to discover whether your nerves are functioning properly. An EMG is one of the tools we use to detect and diagnose pinched nerves.

Can EMG detect MS?

EMG stands for electromyogram. The purpose of the EMG is to assess the health of muscles by measuring their response to stimulation. This can help doctors in diagnosing multiple sclerosis and other conditions when a patient has unexplained muscle weakness.

What medications affect EMG results?

Certain drugs that act on the nervous system (such as muscle relaxants) can interfere with electromyography results. You may need to stop taking these three to six days before the test. Have had bleeding problems or are taking blood thinning drugs, such as warfarin (Coumadin®) or heparin.

Do damaged nerves ever heal?

If a nerve is injured but not cut, your injury is more likely to heal. Injuries in which the nerve has been completely severed are very difficult to treat and recovery may not be possible. Your doctor will determine your treatment based on the extent and cause of your injury and how well the nerve is healing.

Is nerve pain a disability?

If you suffer from a condition that causes nerve damage that is so severe that it impacts your ability to work for at least a year, you may be eligible to receive Social Security Disability benefits.

What does neuropathy pain feel like?

If you have neuropathy, the most commonly described feelings are sensations of numbness, tingling (“pins and needles”), and weakness in the area of the body affected. Other sensations include sharp, lightening-like pain; or a burning, throbbing or stabbing pain.

Do you get EMG results the same day?

Your doctor may review the results with you right after the procedure. However, if another healthcare provider ordered the EMG, then you may not know the results until you attend a follow-up appointment with your doctor.

Will an EMG show a herniated disc?

If you feel pain radiating into your arms or legs, or weakness, tingling, or numbness, an electromyogram (EMG) can reveal whether nerves are being pinched as a result of a herniated disc. An EMG measures the electrical impulses transmitted along nerves, nerve roots, and muscle tissue.

Can EMG detect fibromyalgia?

Conclusions: Fibromyalgia was associated with a specific EMG pattern indicating premature discontinuation of the muscle contraction. Therefore, maximal voluntary muscle contraction tests may be of limited value for assessing function in fibromyalgia patients.

Does EMG measure force?

The amplitude of EMG signal has the potential to provide a measure of the magnitude of muscle force, but this relationship is complicated by both the character of the measured EMG and the mechanics of force production in skeletal muscle.

Does normal EMG mean no ALS?

A normal EMG result will often result in a diagnosis of primary lateral sclerosis (PLS), but does not rule out the possibility of ALS developing later.