Clinical neurophysiology patient information
Find out what to expect from your clinical neurophysiology appointment.
Before your appointment
You can expect to receive an appointment within six weeks of our receiving the referral to our service.
Our diagnostic tests require some advance preparation.
If you are coming to hospital for a nerve conduction study (NCS) or an electromyography (EMG) test, please wear loose-fitting clothing.
If you are coming for an EEG, please come to hospital with freshly washed hair that is free of hair products.
If you are coming to hospital for a sleep-deprived EEG, the night before, you must go to bed late and wake up early, as the procedure must be performed following a night of three to four hours’ sleep. You must not drive on the day of the test, and ensure someone accompanies you to and from your appointment.
You are welcome to bring a family member, friend or carer with you to your appointment. Please be sure to bring your appointment letter, your medications and details of your GP with you.
When you arrive, please check in at the neurophysiology reception desk.
During your appointment
You are welcome to ask for a chaperone and we will endeavour to provide one for you.
Please note that our hospitals are teaching hospitals, so healthcare students may be present for some appointments. If you do not wish them to be present please explain this to your clinician and the students will be asked to step outside.
Your appointment will include one or more of the following diagnostic tests and will last 60 to 90 minutes. Please review your leaflet for detailed information about what you can expect from your tests.
EEG: small disks called electrodes are attached to the scalp with conductive paste (water soluble) for recording small waves from the brain. The EEG recording is combined with video monitoring.
Prolonged EEG: If a routine or sleep deprived EEG fail to provide enough information then prolonged EEG (two to four hours) may be considered, which is similar to the routine EEG but takes a longer period of time.
Ambulatory EEG: If a routine, sleep deprived or prolonged EEG fails to provide enough information then one way to improve the information gained is to perform an ambulatory EEG recording. This involves EEG while you walk around, freely mobile and you are not confined to an EEG department.
Video-telemetry EEG: Video-telemetry EEG recording is very useful to help with the diagnosis of epilepsy. The idea is to capture habitual attacks. This requires admission to hospital and the appointment letter explains the duration of the test.
Nerve conduction studies (NCS): surface electrodes are used for stimulation and recording from the nerves.
Electromyography (EMG) requires insertion of small needle into the muscle.
Thermal threshold test (TTT): TTT is a very simple test to determine sensitivity for small temperature changes (hot and cold). It takes approximately up to 45 minutes. You will be asked to remove all footwear including socks, tights and stockings for the duration of the test.
Visual evoked potential (VEP): These small electrical responses are recorded from the scalp with the help of visual stimulation to the eyes. This is usually performed by attaching small electrodes to the scalp and asking the patient to concentrate on a reversing checkerboard pattern displaced on a monitor. In some cases the patient may be asked to look at flashing light. This study evaluates the integrity of the visual pathway in the brain. There are no side effects of this test.
Somatosensory evoked potential (SSEP): These electrical responses are recorded with small recording electrodes and a sensory stimulus presented to the arms or legs. This study evaluates the integrity of the nerve pathways from the upper and lower limbs to the brain. A sensory stimulus is delivered using a stimulator placed at the wrist or ankle.
Brainstem auditory evoked potential (BAEP): These electrical responses are recorded with the help of auditory stimuli (clicks) at the ear. The test is performed by attaching small electrodes to the scalp with a water soluble paste. An auditory stimulation in the form of clicks is delivered using a pair of headphones.
After your appointment
We complete the results of your test and send them to the consultant who referred you within two weeks of your appointment. The consultant will follow up with you.
Patient information leaflets
- Your ambulatory electroencephalogram (EEG)
- Your brainstem auditory evoked potential test (BAEP)
- Your electroencephalogram (EEG) test
- Your nerve conduction studies/electromyography tests
- Your somatosensory evoked potential test (SSEP)
- Your thermal threshold test (TTT)
- Your visual evoked potential (VEP) test
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