An SEP test studies the relay of body sensations to your brain and how the brain receives those sensations. A stimulating electrode is placed on your arm or leg, and it generates an electrical signal. Recording electrodes are placed on your head and/or spine. The information received from these electrodes can help to diagnose your problem.

What is it?

• The test evaluates the health of your peripheral nerves and your spinal cord.
• It tests how your spinal cord and/or brain transmits information about body sensations through your peripheral nerves.
• It can localize a “signal blockage” either in the relay system (your peripheral nerves act like telephone wires) or in the interpretive center (your brain and spinal cord act like a telephone receiver).

How long does it take?

• About 1 1/2 to 2 hours.

Why is an SEP performed?

• It is used if you are experiencing numbness anywhere, muscle weakness, loss of vibration and position sense, or symptoms following spinal or head injury.

Does it hurt?

• No. During the test your muscles may tingle and twitch, but you will not experience any pain.
• The SEP is not a shock treatment.

Where is it conducted?

• The EEG and Evoked Potential Labs.
• The Lower Level of Carver Pavilion.

How many SEPs are conducted each year?

• Over 200.

What should you do to prepare for the test?

• Eat normal meals.
• You may continue taking prescribed medications unless your doctor gives other instructions.

How is the SEP performed?

• You will recline in a comfortable chair and be asked to remain very still.
• A technologist will glue or tape “recording electrodes” on your head, neck, back, or legs. One or two “stimulating electrodes” are also placed on your arm or leg.
• Each electrode is checked with a meter to ensure proper functioning.
• A pulsing stimulus will start in one of the stimulating electrodes.
• Each time a different area is tested, the pulsing will be started again.
• Each area tested will take 10 to 15 minutes.

Following the test

• The electrodes will be removed with acetone, which dissolves the glue and leaves your hair and skin intact.
• You may return to your hospital room, or go home, unless given other instructions from the doctor.
• You may wash your hair if you wish.
• You will learn the test results either from the doctor on the day of the visit, or from a copy of the letter sent to your personal physician.