Neurodiagnostic testing involves a range of tests which are designed to examine the function of the nerves, muscles and brain, usually by stimulating and recording their electrical activity. These tests include Nerve Conduction Studies (NCS) to measure nerve function, Electromyography (EMG) to measure nerve and muscle function, Electroencephalography (EEG) to assess brain function, and Evoked Potentials (EP) to measure the brain's response to various sensory inputs, like vision or hearing.
Your neurophysiology technician will use specialised computerised equipment to record the information, under the supervision of a Neurologist. A detailed analysis is undertaken by the Neurologist, and a report with your results is sent to your referring doctor.
An Evoked Potential study records the response from the brain after a stimulus. Electrodes are applied to the scalp to record the brain response, this may require some rubbing of the skin. You can help us obtain good quality results by having clean, dry hair and avoiding hair spray or gel on the day of your test. The stimulus may be a black and white pattern for a Visual Evoked Potential (VEP), small electrical pulses for sensory Sensory Evoked Potentials (SEP), and loud clicks for hearing and balance testing (Brainstem Evoked Potentials, BAEP; and Vestibular Evoked Myogenic Potentials, VEMP).
The EEG is a recording of electrical activity from the surface of the brain. It usually takes about 30 or 45 minutes. A series of electrodes are applied to the scalp. Because the recording is very sensitive, this may involve some rubbing of the skin to ensure a good contact. You can help by having clean, dry hair, and avoiding hair spray or gel on the day of the examination.
Mostly you will be resting quietly in a chair with your eyes closed; it is important to remain quiet and keep the head still so the recording is of good quality. The technician may ask you to breathe heavily for 3 or 4 minutes (hyperventilation), this can make you feel light head but will settle quickly. Towards the end of the testing, the brain is stimulated also with a special strobe light at different frequencies. Please let us know if you have any concerns or are uncomfortable at any time.
If your doctor has requested a sleep deprived recording, you will usually have to stay up the night before and come in for your test early the next morning. Please ask for instructions from the reception staff.
The system in your body responsible for hearing and balance is known as the vestibular system. At Newcastle Neurodiagnostics, we perform a range of vestibular tests with a special interest in vertigo and balance disorders.