Establishing the nature and extent of a neurological condition is an important first step to receiving proper care. If your neurologist suspects you have a neuromuscular disorder, such as multiple sclerosis, or other nervous system damage, you may need an evoked potentials test.
An evoked potentials test measures the amount of time it takes for your nerves to respond to stimulation, as well as the size of the response. There are three main types of evoked responses that are measured, including:
- Visual Evoked Response—Occurs when your eyes are stimulated by light or looking at a screen with a pattern on it.
- Auditory—Occurs when your hearing is stimulated by listening to a test noise sent through headphones.
- Somatosensory—Occurs when the nerves of your arms and legs are stimulated by a mild electrical pulse.
During an evoked potentials test, your neurologist or electroneurodiagnostic technologist applies conducting gel and electrodes to your scalp, as well as other locations on your body. A stimulus, whether it be auditory, visual or sensory, is provided and the electrodes measure the time it takes for your nerves to respond to the stimulation. A computer interprets this data, measuring the size of your brain’s response and identifying the location of any nerve damage.
The test typically takes about 30 minutes to an hour to complete. Talk to your doctor about whether this test is right for you.