What is the purpose of nerve conduction studies?

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The article was professionally consulted by a Doctor of Medical Examination & Internal Medicine - Vinmec Central Park International General Hospital
The neurologic examination is very meticulous and nerve conduction studies help to check that the nerves are conducting electrical signals well and quickly.

1. What is a nerve conduction study?

Nerve conduction study is essentially a test to see if the nerves conduct electrical signals well, fast or slow conduction. This survey can be performed for many different types of peripheral nervous system disease. Investigation is applicable to most peripheral nerve roots and nerves.
Nerves act like electrical cables. Nerves use electrical impulses to transmit information between the brain and other parts of the body. The brain sends signals in the form of electrical impulses through the spinal cord, to the peripheral nervous system. Peripheral nerves can be motor nerves, transmitting signals to muscles and causing muscle contractions. Or it can be a sensory cord, which transmits sensory signals from sensory receptors to the brain, to recognize sensations of hot - cold, pressure, touch sensation... Or it can be a mixed nerve has both a motor component and a sensory component. Motor nerves use electrical signals to contract muscles, and sensory nerves send information from the surrounding environment to the brain through electrical impulses.
Most nerves are covered by a myelin sheath. The myelin sheath helps electrical impulses travel faster and more efficiently. If the myelin sheath is lost, the electrical signals will travel more slowly. In summary, the conduction velocity of electrical impulses can be probed by nerve conduction survey.

2. Purpose of nerve conduction studies

Neurological examination evaluates nerve damage due to trauma. Checking for nerve damage due to pathology (diabetes...) Evaluation of diseases affecting the peripheral nervous system. Check for a pinched nerve (carpal tunnel syndrome...)

3. The process of studying nerve conduction

The nerve is stimulated with a small electrical pulse created by an electrode that is glued to the skin. The small electrical impulses generated by the machine resemble electrical signals from a nerve, if it is a motor nerve, the muscle will contract in response to the electrical signal.
For sensory nerves, the stimulation electrodes are usually attached to the fingers or toes, while the recording electrodes are placed at the wrist or ankle (depending on the different nerves, the specific location). The electrodes will be placed in different positions). When the electrical impulses from the electrode stimulate and stimulate the fingers and toes, the sensory nerves will carry these electrical signals. transmitted along the nerve to the recording electrode and recorded by the measuring device. Measuring the time the electrical impulse travels in the nerve from the stimulation electrode to the guitar electrode will get the conduction time, combined with measuring the distance between the two electrodes will calculate the conduction speed of the sensory nerve. sense (V=S/T).
Some electrodes are attached to the skin with adhesive tape or a special paste. The stimulating electrical impulses feel like a prick in the skin, which most people don't find too uncomfortable. Nerve conduction studies last from 14 minutes to 1 hour or longer depending on the number of nerves and muscles to be examined.
If you are taking a medication, such as a muscle relaxant or anticholinergic, your doctor will ask you to stop taking it a few days before the test. Patients need to keep their limbs warm because if the hands and feet are cold, the speed of the electrical impulses will decrease. Do not put creams or moisturizers on your hands. Wear loose clothing that lifts clothes above the elbows and knees easily. Remove bracelets, rings, watches when surveying on the hand, remove socks and belts when examining the legs.

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