Evoked potentials (EP) measure your brain’s response to a sensory stimulus. There are three main types of evoked potentials:
- Visual evoked potentials (VEP). Visual evoked potentials are a test of your visual system, including your optic nerves. The test is not painful. Electrodes are applied to your scalp with a sticky paste. You then sit in front of a computer screen with one eye covered. When testing begins, a black-and-white checkerboard pattern flashes on the screen. All you have to do is watch a red dot in the middle of the screen for a few minutes. The procedure is then repeated with the other eye covered.
- Somatosensory evoked potentials (SSEP). Somatosensory evoked potentials (SSEPs) test the function of the entire somatosensory pathway, from nerve to spinal cord to brain. SSEPs can be performed on your arms or legs. As you lie flat, electrodes are applied to your scalp as well as locations along your spine using a sticky paste. A stimulator is placed on your wrist or ankle. You then feel a repetitive electrical stimulus under the stimulator. This may be annoying, but it should not be painful. You close your eyes and relax for several minutes while your brain response is recorded. The procedure may be repeated on your other side.
- Brainstem auditory evoked response (BAER). Brainstem auditory evoked responses test the function of the auditory pathway from the ear to the auditory nerve to the brain. The test is not painful. Electrodes are applied to your scalp with a sticky paste, and headphones are placed over your ears. When testing begins, you hear a clicking noise in one ear. All you have to do is close your eyes and relax. After a few minutes, when the recording is complete, the other ear is tested.
Talk to your physician about whether evoked potentials are appropriate for you. For referral appointments, please call Jessica Robinson-Papp, MD, at 212-241-8390. Evoked potentials are performed in the clinical neurophysiology area, located in the Annenberg Building, second floor (area 218).