Electrodes delivering stimuli may be placed on the lower back, wrist, knee, or ankle over peripheral nerves that are known to function properly. Minute electrical shocks are delivered to the peripheral nerves. Signals produced by the brain in response to every shock are recorded. After the test You are free to return to previous activities. Factors affecting results Severe nearsightedness.
Muscle spasms in the head or neck.
Earwax or severe inflammation of the middle ear. Interpretation Evoked signals are faint compared with the brain's background electrical activity. In the test, the signals are amplified, separated from the background, and presented as a wave. The doctor examines the waves and detects abnormalities that are characteristic of various disorders. It's noninvasive and safe.