Somatosensory Evoked Potential (SSEP)

Patient Leaflets Team

  • Reference Number: HEY-765/2019
  • Departments: Neurophysiology
  • Last Updated: 31 May 2019


This leaflet has been produced to give you general information about your procedure.  Most of your questions should be answered by this leaflet.  It is not intended to replace the discussion between you and the healthcare team, but may act as a starting point for discussion.  If after reading it you have any concerns or require further explanation, please discuss this with a member of the healthcare team.

What is a Somatosensory Evoked Potential Test (SSEP)?

A SSEP will be performed by a clinical physiologist.  It is a way of stimulating the nerves in the arm and leg with electrical impulses and recording the response from the brain and other parts of the body.  The responses are recorded by a computer and the tests interpreted afterwards by a doctor in the department.

Why do I need a SSEP?

A SSEP is commonly performed to assess the condition of the nerve pathway if patients are suffering certain symptoms in the arms, legs or both.  It can also be performed if a patient is queried as having a general nerve problem.

Can there be any complications or risks?

  • Very occasionally people may experience a slight local reaction at the electrode site. This may cause reddening and soreness.  These symptoms resolve quickly on removal of the electrodes. If you experience these symptoms, please inform the staff attending to you.
  • Occasionally patients are unable to tolerate the electrical stimulus and if this is the case your referring clinician will be informed.

How do I prepare for a SSEP?

Please read this information leaflet.  Share the information it contains with your partner and family (if you wish) so that they can be of help and support.  There may be information they need to know, especially if they are taking care of you during/following this examination.

  • Try and attend for your SSEP test with warm hands and feet, for example wearing gloves in colder weather and socks.
  • Do not put moisturiser on your body unless of a medicinal nature, for example for eczema/psoriasis.
  • Wash your hair before your appointment and leave it free from hair gel, spray etc.
  • Please wear a top that either buttons up or has a wide neck and be sure we can get to your elbow area, for example sleeves that will roll up.

What will happen?

  • On your arrival in the department we will obtain your consent for the procedure before your investigation begins.
  • The clinical physiologist performing the SSEP will explain the test to you and will be happy to answer any questions you may have.
  • Generally we ask people to come into the examination by themselves as experience shows people to be generally more relaxed.
  • You will be asked to sit on a chair and have your head measured and some points will be marked on it with a soft pencil.
  • You may be asked some questions about the condition leading to your referral for a SSEP.
  • Several electrodes will be placed on your head, neck, shoulder and arm with some sticky paste and you will be asked to lay back in the chair and relax.
  • An electrical stimulator will be placed on your wrist or ankle and a current delivered which you will feel as a pulsing sensation. This stimulus will get stronger until a twitching movement is observed in your hands or feet.
  • Once enough responses have been recorded the test can be ended and you will usually be in the department no longer than 1 hour.
  • After the test the electrodes will be removed and any residual paste cleaned from your hair. You will need to wash your hair once you return home.

What happens afterwards?

  • Once you have left the department the recording will be reviewed by the physiologist and then by a member of the medical team who will send a report to the doctor who referred you for the SSEP.
  • This usually takes up to two weeks.

Should you require further advice on the issues contained in this leaflet, please do not hesitate to contact the Neurophysiology Department (01482) 675339 / 675388

General Advice and Consent

Most of your questions should have been answered by this leaflet, but remember that this is only a starting point for discussion with the healthcare team.

Consent to treatment

Before any doctor, nurse or therapist examines or treats you, they must seek your consent or permission. In order to make a decision, you need to have information from health professionals about the treatment or investigation which is being offered to you. You should always ask them more questions if you do not understand or if you want more information.

The information you receive should be about your condition, the alternatives available to you, and whether it carries risks as well as the benefits. What is important is that your consent is genuine or valid. That means:

  • you must be able to give your consent
  • you must be given enough information to enable you to make a decision
  • you must be acting under your own free will and not under the strong influence of another person

Information about you

We collect and use your information to provide you with care and treatment. As part of your care, information about you will be shared between members of a healthcare team, some of whom you may not meet. Your information may also be used to help train staff, to check the quality of our care, to manage and plan the health service, and to help with research. Wherever possible we use anonymous data.

We may pass on relevant information to other health organisations that provide you with care. All information is treated as strictly confidential and is not given to anyone who does not need it. If you have any concerns please ask your doctor, or the person caring for you.

Under the General Data Protection Regulation and the Data Protection Act 2018 we are responsible for maintaining the confidentiality of any information we hold about you. For further information visit the following page: Confidential Information about You.

If you or your carer needs information about your health and wellbeing and about your care and treatment in a different format, such as large print, braille or audio, due to disability, impairment or sensory loss, please advise a member of staff and this can be arranged.

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