05/30/2023
EEG TESTING
Howard Memorial Hospital offers EEG testing through the Respiratory Care Department. Below is information about EEG testing, the process, and why you might need to have this testing done. If you feel that you might be a candidate for this testing then please make an appointment with your family physician to discuss this. If you want more information about this testing, please feel free to call our office @ 870-845-6942 and we will be happy to help you.
What is an EEG?
An EEG is a test that detects abnormalities in your brain waves, or in the electrical activity of your brain. During the procedure, a cap with electrodes is placed on your head. The electrodes detect tiny electrical charges that result from the activity of your brain cells. The charges are amplified and appear as a graph on a computer screen, or as a recording that may be printed out on paper. A physician trained to read EEGs will then interpret the test and send a report to your physician.
Why might I need an EEG?
• The EEG is used to evaluate several types of brain disorders. When epilepsy is present, seizure activity will appear as rapid spiking waves on the EEG. If you have been diagnosed with a seizure disorder previously and are on medication, you may need an EEG to assess the effectiveness of your medication if you are having break through seizures.
• People with lesions of their brain, which can result from tumors or stroke, may have unusually slow EEG waves, depending on the size and the location of the lesion.
• The test can also be used to diagnose other disorders that influence brain activity, such as Alzheimer's disease, certain psychoses, and a sleep disorder called narcolepsy.
• The EEG may also be used to determine the overall electrical activity of the brain (for example, to evaluate trauma, drug intoxication, or extent of brain damage in comatose patients).
• There may be other reasons for your healthcare provider to recommend an EEG such as migraines or if you are having episodes of loss of consciousness or memory loss.
What are the risks of an EEG?
The EEG has been used for many years and is considered a safe procedure. The test causes no discomfort. The electrodes record activity. They do not produce any sensation. In addition, there is no risk of getting an electric shock.
In rare instances, an EEG can cause seizures in a person with a seizure disorder. This is due to the flashing lights or the deep breathing that may be involved during the test. If you do get a seizure, your healthcare provider will treat it immediately.
Other risks may be present, depending on your specific medical condition. Be sure to discuss any concerns with your healthcare provider before the procedure.
Certain factors or conditions may interfere with the reading of an EEG test. These include:
• Low blood sugar (hypoglycemia) caused by fasting
• Body or eye movement during the tests (but this will rarely, if ever, significantly interfere with the interpretation of the test)
• Lights, especially bright or flashing ones
• Certain medicines, such as sedatives
• Drinks containing caffeine, such as coffee, cola, and tea (while these drinks can occasionally alter the EEG results, this almost never interferes significantly with the interpretation of the test)
• Oily hair or the presence of hair spray
How do I get ready for an EEG?
Ask your healthcare provider to tell you what you should do before your test. Below is a list of common steps that you may be asked to do.
• Wash your hair with shampoo, but do not use a conditioner the night before the test. Do not use any hair care products, such as hairspray or gels.
• Bring a list of all medicines (prescription and over-the-counter) and herbal supplements that you are taking.
• Discontinue using medicines that may interfere with the test if your healthcare provider has directed you to do so. Do not stop using medicines without first consulting your healthcare provider.
• Avoid consuming any food or drinks containing caffeine for 8 to 12 hours before the test.
• Some EEG tests require that you sleep through the procedure, and some do not. If the EEG is to be done during sleep, adults may not be allowed to sleep more than 4 or 5 hours the night before the test. Children may not be allowed to sleep for more than 5 to 7 hours the night before.
• Avoid fasting the night before or the day of the procedure. Low blood sugar may influence the results.
• Based on your medical condition, your healthcare provider may request other specific preparations.
What happens during an EEG?
An EEG may be done on an outpatient basis, or as part of your stay in a hospital. Procedures may vary depending on your condition and your healthcare provider's practices.
Generally, an EEG procedure follows this process:
1. You will be asked to relax in a reclining chair or stay in your bed if you are an inpatient.
2. A cap containing electrodes will be placed on your head and the holes in the electrodes will be filled with a special paste and gel to help strengthen the connection.
3. You will be asked to close your eyes, relax, and be still.
4. Once the recording begins, you will need to remain still throughout the test. Your Respiratory Therapist will perform the test through a computer attached to a long wire on the cap. The recording may be stopped periodically to let you rest or reposition yourself.
5. After your healthcare provider does the initial recording while you are at rest, he or she may test you with various stimuli to produce brain wave activity that does not show up while you are resting. For example, you may be asked to breathe deeply and rapidly for 3 minutes, or you may be exposed to a bright flashing light.
6. This study will be done in the Respiratory Care Department by the Respiratory Therapist at HMH and may take approximately 45 minutes to 1 hour.
What happens after an EEG?
Once the test is completed, the cap is removed and the electrode paste will be washed off with warm water. In some cases, you may need to wash your hair again at home.
If you took any sedatives for the test, you may be required to rest until the sedatives have worn off. You will need to have someone drive you home.
Skin irritation or redness may be present at the locations where the electrodes were placed, but this will wear off in a few hours.