An evoked potentials test measures the speed of nerve messages along sensory nerves to the brain and is sometimes used in the diagnosis of MS. Your brain produces electrical current in response to information that comes in through your senses. This current can be detected on your scalp, using electrodes attached with sticky pads. In this video Professor Coles takes us through what happens in a evoked potential tests, what different ones there are and how they work. For more info have a look at o