5441 Babcock Road Ste 301, San Antonio TX, 78240
Office: (210) 641-1394 | Fax: (210) 561-2846
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Electroencephalogram (EEG)

An electroencephalogram is a test that records the electrical waves of the brain. It is a safe, easy, and painless test that takes approximately one and a half hour(s) at the Clinic. Electrodes are applied to the scalp and the waves from your brain are recorded while you sit comfortably in a recliner.

Before an EEG

A physician’s prescription or referral is required before scheduling an EEG. It is requested that you have clean, dry hair for testing. Your hair should be clean and free of hair spray, oil, tonic, hair weaves, extensions or wigs.

This allows the electrodes to stay in place and provide a proper recording. You should continue to take your normal medications unless otherwise indicated by your physician. Eating prior to the test is recommended to help stabilize your blood sugar levels. In certain instances, you may be asked to adjust your sleeping schedule and avoid consuming products with caffeine (tea, coffee, and cola) to enable you to sleep during the test.  The technologist, or Clinic staff, will obtain a history from you, including your current medications.  Do not stop taking your prescribed medications unless specifically told to do so by your physician.

We make every attempt to obtain a natural sleep recording, so do not consume any caffeine containing beverages the morning of the test, which include coffee, tea, cola, and chocolate drinks.

During an EEG

The technologist will apply the electrodes to your scalp. During the test, you may be asked to hyperventilate (fast, heavy breathing), sleep, and/or watch a flashing light (photic stimulation). These are all normal procedures done to better evaluate your EEG. Your cooperation is essential. The technologist will ask you to relax, avoid unnecessary movements, and refrain from speaking unless needed. After the test, the electrodes will be removed and the water soluble paste will be cleaned from your hair. If you have any questions, feel free to ask before or after the test.

The test is run on a computer that looks like the ones you have in your own homes and in schools. We will be applying approximately 25 electrodes and two EKG stickers on the chest to measure your heart beat as well. The electrodes are 48” long and multi-colored with a disc or cup on the end that is attached to the scalp by an adhesive method. This small disc is made of pure silver with gold plating over it. These electrodes are plugged into a jack box that has a cable attached to the computer. In looking at EEG patterns, we compare the left side of the brain to the right side, so these electrodes must be placed very precisely. The application can take between 30 and 40 minutes.

Your doctor may order a Routine EEG or a Multi-hour or longer EEG. For the Routine EEG you will be allotted 90 minutes for the appointment, and this will include the electrode application process, the actual running of the test which is greater than 60 minutes, along with the clean up process.

After an EEG

A neurologist specially trained in reading EEGs will interpret the test. The technologist performing the test is not permitted to provide results to the patient during the procedure. The neurologist will review your test and dictate a report that contains the results of your EEG. The physician that ordered the test will receive the report, and discuss the results with you.