What is an electroencephalogram or EEG?
What is an EEG?
An electro-cephalogram is a test which uses small, metal disks (electrodes) attached to the skin to detect electrical activity in your brain. Your brain cells communicate in the form of electric impulses and are active constantly, even if you sleep. This activity appears in an EEG recording as wavy lines.
EEG is one of the most important epilepsy diagnostic tests. An EEG can also be used to diagnose other brain disorders.
An EEG tracks and registers patterns of the brain wave. The scalp is joined to with the wires in small flat metal disks called electrodes. The electrodes test and send signals to a computer which records the results of electrical pulses within the brain.
In an EEG recording, the electrical pulses are wavelengths with peaks and valleys. These guidelines enable doctors to assess quickly if abnormal patterns exist. Irregularities can be a sign of convulsions or other disorders of the brain.
Why do we do EEG?
A EEG can identify brain activity changes that could be useful for the diagnosis of brain disorders , particularly epilepsy or another seizure disorder. An EEG may also be helpful in the diagnosis or treatment of:
- Seizure disorders (for example epilepsy)
- Head injuries
- Encephalitis (a brain inflammation)
- Cerebral tumour
- Encephalopathy (Brain Dysfunction Disorder)
- Memory Issues
- Sleep troubles
An EEG may be performed to determine the brain activity level when someone is in a coma. The test may also be used in brain surgery to monitor activity.
Are there any EEG-related risks?
An EEG does not pose any risks. The test is safe and painless.
There are no EEGs that contain light or other stimuli. If EEG does not cause abnormalities, stimuli like strobe lights or fast breathing can be added to trigger abnormalities.
If someone has epilepsy or other seizure disorder, the stimuli (for instance a flashing light) presented during the test may cause a convulsion. The EEG technician is trained to handle any possible situations safely. What is an electroencephalogram or EEG?
How do I get ready for EEG?
Before the test, the following steps should be taken:
- Wash your hair before EEG the night and do not put any products in your hair on the day of testing (such as sprays or gels).
- Ask your doctor whether you should stop taking drugs before the test. You should also give the technician who performs the EEG a list of your medicines.
- No caffeine-containing food or drink for at least eight hours before the test.
The night before the test, if you have to sleep during EEG, your doctor may ask you to sleep as little as possible. A sedative can be given to help you sleep and relax before the test starts.
You can proceed with your regular routine after the EEG is over. If you have been given a sedative, the drugs are kept for a while in your system. So you will need to take somebody with you so that after the test they can bring you home. You will have to rest until the medication wears down and avoid driving.
During an EEG what can I expect?
An EEG measures the electrical impulses in the brain by using multiple electrodes on your scalp. An electrode is a conductor that enters or leaves an electrical current. Electrodes transmit information from your brain to a data-measuring and recording machine.
Specialist technicians manage EEG’s in hospitals , physicians and labs. The test is generally completed within 30 to 60 minutes and includes:
You will sit in a chair or on a bed on your back.
The technician will measure your head and indicate where the electrodes are placed. Special cream is used to scrub these spots to help the electrodes get a high-quality reading.
The technician will attach 16 to 25 electrodes to a sticky gel adhesive and attach it on the scalp.
Once the test starts, the electrodes send the data from their brain electrical impulses to the machine. This machine transforms the electrical impulses into visual patterns on a monitor. These patterns are saved by a computer.
You can be instructed by the technician to do certain things during the test. You can ask for rest, closure of your eyes, respiration or stimuli (such as a flashing light or picture).
The technician removes the electrodes from your skin after the test is complete.
The test takes place between the electrodes and the skin, with very little electricity so that you feel very little to no discomfort.
In some cases, an individual can receive a 24-hour EEG. These EEGs use video to record seizures. Even if the seizure doesn’t happen, the EEG can show abnormalities. It does not, however, always show past seizure abnormalities. What is an electroencephalogram or EEG?
What does the results of the EEG test mean?
A neurologist (anyone specializing in nervous system conditions) can interpret the EEG records and send your doctor the results. Your doctor may appoint you to review the test results.
In the EEG, electric activity in the brain is shown as a wave pattern. Various levels of consciousness, such as dreaming and waking, are considered normal and have a certain number of wave frequencies per second. For example, if you are awake, the wave patterns move faster than sleeping. The EEG will show whether the wave or pattern frequency is normal. Typically, normal activity means that you have no brain disorder.
The results of abnormal EEG may be:
- Epilepsy or another conflagration
- Bleeding or bleeding abnormally
- Disorder of sleep
- Brain swelling (encephalitis)
- the cancer
- Blocking blood flow to the dead tissue
- Drug abuse or alcohol
- Injury to the head
It is very important to talk to your doctor about your test results. It might be useful to write down any questions you would like to ask before you check the results. Be sure to talk up if you don’t understand anything about the results.