Somatosensory evoked potential, or SSEP, is a test that shows the electrical signals of sensation going from the body to the brain. The signals show whether the nerves that connect to the spinal cord are able to send and receive sensory information like pain, temperature, and touch. This test is ordered by your physician when he or she wants to evaluate a number of neurological problems, including spinal cord injuries, optic neuritis, multiple sclerosis and acoustic neuroma.
The SSEP indicates whether the spinal cord or nerves are being pinched. It is helpful in determining how much the nerve is being damaged and if there is a bone spur, herniated disc, or other source of pressure on the spinal cord or nerve roots. Electromyography, or EMG, is used to show if a nerve is being irritated or pinched as it leaves the spine on it way down the arm or leg. During a spine surgery, the EMG is used to monitor nerve output to the muscles in procedures where screws are being placed in the middle or lower part of the spine. The SSEP is used to check whether the sensory part of the nerve is working correctly.