Evoked Potentials (EP) tests are used to check the condition of the nerve pathways. They measure the brain’s electrical response to the signals sent by the nerves. EP tests help diagnose nervous system abnormalities, hearing loss, and assess neurological functions.

Major Types of Evoked Potentials (EP) Tests

  • Brainstem Auditory Evoked Potential – Checks the pathway from the ear to the brain. The BAEP test may help uncover the cause of hearing and balance problems, and other symptoms.
  • Visual Evoked Potential – Checks the pathway from the eyes to the brain. May help find the cause of certain vision problems and other conditions.
  • Somatosensory Evoked Potential – Checks the pathway from the nerves in the limbs to the brain. It is a way to study the function of the nerves, the spinal cord and brain.

Preparation:

  1. Wash your hair the night before the test. Do not use any oils or lotions.
  2. Eat a normal meal at your usual mealtime before the test.
  3. Avoid caffeine.
  4. Bring glasses or contact lenses for the Visual Evoked Potential test. Procedure: • Positioned on a reclining chair or bed and asked to relax, remain still. • Electrodes placed on your scalp, along the vertex and on each earlobe. • A mild stimulus is applied to the eyes, ears or limbs. • Clicking noises or tone bursts heard through earphones. • The electrodes pick up the brain’s response and record it on a graph. How It Feels

Procedure:

  1. Positioned on a reclining chair or bed and asked to relax, remain still.
  2. Electrodes placed on your scalp, along the vertex and on each earlobe.
  3. A mild stimulus is applied to the eyes, ears or limbs.
  4. Clicking noises or tone bursts heard through earphones.
  5. The electrodes pick up the brain’s response and record it on a graph.

How It Feelsa:

  • Very little discomfort is experienced.
  • The test is usually performed within an hour, and is painless and safe.