What are evoked potentials?
Evoked potentials (EPs) measure electrical activity produced by external stimuli, like light flashes or sound clicks. EPs are done to test the auditory pathways (brain stem auditory evoked potentials), visual pathways (visual evoked potentials), and the somatosensory pathways (somatosensory evoked potentials). These are especially useful if your child has difficulty communicating.
In an EP study, electroencephalogram (EEG)-like recording electrodes are placed on your child’s scalp that stimulate the appropriate pathways. Visual evoked potentials are done by either looking at a changing checkerboard pattern or at a flashing light. Auditory evoked potentials are done by stimulating the auditory system with a clicking noise. Special auditory EP techniques allow a determination of whether poor hearing results from inner ear, nerve to the ear, or brain problems. Somatosensory evoked potentials are done by giving a small electrical impulse to the extremities.
Your child might require sedation for an EP.
Department of Otolaryngology and Communication Enhancement
Boston Children's Hospital
333 Longwood Avenue
Boston, MA 02115