MEP (Motor evoked potential) test: MEPs are recorded from muscles following transcranial magnetic stimulation of the motor cortex. This test can be used to assess the integrity of the motor pathway from the brain to the muscle in brain injured patients. SEP (Somatosensory evoked potential) test: SEPs are recorded by stimulating peripheral nerves, most commonly the posterior tibial nerve, median nerve or ulnar nerve, with an electrical stimulus. The response is then recorded from the patient's scalp. Using this test we can determine the integrity of the sensory pathway from the distal limbs to the brain.