Somatosensory Evoked Potential  (SSEP)

What is Somatosensory Evoked Potential (SSEP)?

SSEP is a test that records how quickly and effectively electrical signals in the brain and spinal cord are received, in response to sensory stimulation. 

Your doctor may recommend this test to:

• Checks the nerve tracts that connect the upper and lower limbs to a part of the brain that enables you to feel objects.
• Help diagnose conditions of the brain and spinal cord such as multiple sclerosis or spinal cord injury
• Investigate numbness or tingling sensations in your limbs, difficulty in walking or maintaining balance. 

This list is non-exhaustive.

How should I prepare for SSEP?

• Please inform the appointed neurodiagnostic laboratory managing your test if you have an implanted electronic device, such as a heart pacemaker, defibrillator, intracranial device or neurostimulator.
• Wear loose clothing such as a loose shirt, blouse, or shorts
• Avoid using body lotion and hair styling products e.g. foam, cream, gel, oil
• Not required to fast
• Continue with your regular diet and medications

How is SSEP performed?

The test is done by a neurotechnologist and will take:

1. Around 1.5 hours when done on the arms or legs 
2. Around 3 hours when done on both the arms and legs.

• This test is done while you are lying down on the bed
• Your scalp, neck, lower spine and back of the knees are cleaned using a gel.
• Electrodes are attached to these areas using a safe and washable paste.
• A mild electrical impulse is applied to your wrists, ankles or both areas. Your thumb or toe will twitch, and you may feel a tingling sensation.
• The test is done on one wrist or ankle at a time and repeated on the other side.
• The electrodes record your brain’s responses to the stimulus.
• Once the test is done, the electrodes are removed, and you can go home.
• A detailed report will be sent to your doctor within two weeks. Your doctor will discuss the findings with you at your next appointment.

Frequently Asked Questions about SSEP

Is the test safe?

The test is considered safe: 

• Non-invasive (no needles)
• The electrical pulses used to stimulate the nerves are very mild.
• A neurotechnologist will be present throughout the process. If you feel unwell, please inform the neurotechnologist. 

Can I use Medisave to pay for this test?

This test may be claimable under:

• Flexi-MediSave for Seniors; or
• Outpatient scans for diagnosis or treatment of a medical condition.

Please refer to the Ministry of Health's Outpatient Care page for the latest claim limits and eligibility criteria.

The information is correct as of July 2026 and subject to revisions without notice.
Content adapted from NNI Neurodiagnostic Laboratory (NDL), NNI@TTSH.