Neurological Tests

The Genesis Neurodiagnostic Center is staffed by registered technologists and accredited by The American Board of Registration of Electroencephalographic and Evoked Potential Technologists (ABRET). Your technologist will explain and prepare you for your test with compassion and understanding.

Diagnosing Neurological Disorders

You benefit from technologically advanced resources to diagnosis your condition. Your neurologist may request:

  • Electroencephalograms (EEG) – Monitors electrical brain activity
  • Electronystagmography (ENG/VNG) – Monitors inner and central motor function
  • Ambulatory EEG
  • Long Term Monitoring & Intensive/Surgical Monitoring
  • Evoked Potential - Records electrical activity of your brain in response to sight, sound or touch

Neurological Tests

Find out more about the test your physician ordered. If you need to reschedule or cancel your appointment please call (563) 421-3200.


About the Test

An EEG is a graphic record of brain waves representing electrical activity in the brain, used especially in the diagnosis of seizures and other neurological disorders. The EEG is not treatment. The EEG machine does not send electrical impulses, cannot read your mind and cannot affect the brain. There are no needles or pain involved with the test.

A technologist will measure your head and apply 26 disc electrodes (wires) with a paste or glue. Once wires are on, you will be asked to lay down with your eyes closed for about 20-30min. A technologist will be talking to you through an intercom during this time and will be giving you instructions throughout test. Total time you will be here for test (setup and recording) is 1-2 hours.

Preparation for EEG

  • Shampoo hair evening before test. Do not use hair spray, gel, or other hair products..
  • We want you to be tired to increase the likelihood of getting you to sleep during the test.
  • Limit your sleep to 4 hours the night before test.
  • No caffeinated beverages
  • Bring list of current medications


Why was this test ordered?

An ENG is ordered to gain information about a patient's complaint of disturbed equilibrium (dizziness, light headed, etc.). The ENG will help the physician to distinguish between a peripheral vestibular disorder and one located with in the central nervous system.

About The Test

Goggles will be worn to record eye movements, while the patient is asked to focus on a visual aid and turn head at different angles.

The test takes approximately 2 hours.


  • Do not eat or drink 12 hours prior to scheduled test.
  • Do not apply lotion or make-up around the eyes
  • If you wear glasses, bring your glasses on the day of the test (or wear contact lens).
  • Bring list of current medications

There are certain medications that may be withheld for a period of time before this test. Please check with your physician if you are taking any of these medications, as some may affect the test results and you may need to stop them temporarily.

  • Alcohol in any quantity, including cough medicine
  • Anti-Nausea medications
  • Anti-vertigo medications
  • Anti-anxiety medications
  • Antihistamines
  • Barbituates
  • Narcotics

You will need a driver. Patients experience some dizziness after the test.


About the Test

The first day of an Ambulatory EEG set up procedure lasts one hour. The EEG technologist will attach 26 flat metal discs called electrodes to different places on your head, using a special glue called collodion. The electrodes are connected by wires to a small recorder that you can wear around your waist or shoulder.

A 30 min appointment will be made daily (until wires are removed) for the technologist to replace batteries and reapply wires as needed. Your doctor will specify on the order how long the wires are to be worn (ie 48hrs, until spell, 72hours or until spell).

You will be asked to keep a diary of activities and symptoms. The recorders has an “event” button to press if you experience any of the symptoms for which you are being tested, such as episodes of feeling “spacey” or confused. A family member should press the button if the patient is unable to do it.

While the electrodes are on we will ask you not to shower or take a bath (Other than sponge bath) as water will damage the machine. If test goes longer than 7 days, wires will be removed on the 7th day so you can shower and then the wires will be reapplied.

Preparation for EEG

Shampoo hair evening before test. Do not use hair spray, gel, or other hair products.


About the Tests

Small discs (electrodes) will be applied to your scalp with conductive paste to monitor the electrical activity of your brain. A stimulus will be induced and your brain's response to (or recognition of) the stimulus will be recorded. Evoked Potentials are noninvasive tests.


This test measures how information travels from the back of the eyes through the nervous system to the visual lobe of the brain. You will be required to stay alert and stare at a television screen displaying a checkerboard pattern. If you wear glasses please bring them with you. This test takes approximately one hour.

Brainstem Auditory

This test measures how information travels from the ear through the auditory pathways of the brainstem. Headphones will be placed on your ears. You will lie in a recliner or bed and rest while you listen to a series of "clicks". This test takes approximately one hour.


This test measures how sensory information travels through the nervous system to the brain with stimulation of the arm and/or leg. A probe will be placed over a nerve in your wrist (upper) or over a nerve in your ankle (lower). A mild electrical current is passed through the probe stimulating the nerve. Additional electrodes will be placed on your  neck and lower back. This test takes approximately 1-2 hours.


  • Shampoo and dry hair prior to test. Do not use hairspray or other hair products

  • Bring list of current medications with you to your appointment


The Neurodiagnostic and Sleep Center is located at the Genesis Medical Center, West Campus. Park on the north side of the hospital and enter through the Emergency entrance. Walk straight back, following the blue line in the carpet. When the blue line meets the green arrow continue to go straight following the green line until you reach the red arrow. At the red arrow you will find the Neurodiagnostics and Sleep Disorders center to your right.