How Do You Read Results of an EMG Nerve Conduction Test?

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Reading results of an EMG nerve conduction test means looking for bursts of muscular electrical activity recorded on a paper or a computer screen against a grid, as described by Electrodiagnosis & Rehabilitation Associates of Tacoma. EMG and nerve conduction tests are often done at the same time to determine if a problem originates as a muscle issue or a nerve issue.

EMG stands for electromyography. It measures what the electrical impulses sent a by nerve into muscle tissue does, according to WebMD. A nerve conduction test measures the speed of conduction of an electrical impulse in a nerve. Done together through insertion of small needles into muscles, doctors can diagnose problems such as numbness or muscular pain.

On a screen the dark background color has a grid overlay. In the center lies a baseline. When the test begins, spikes record above the baseline and below the baseline. Along the sides and the baseline, the equipment takes a measurement. These measurements quantify muscular response or nerve conduction, as explained by Electrodiagnosis & Rehabilitation Associates of Tacoma. Muscles in pain have upward spikes close together showing continuous contraction of muscle without much space in between. Nerve conduction that is slow shows spikes, but they do not have much height and linger on a plateau, indicating numbness or nerve damage.