What is an EEG (electroencephalogram) test?
An EEG (electroencephalogram) is a procedure that looks for irregularities in the electrical signals in your brain or brain waves.
Your scalp will be covered in electrodes, which are tiny metal plates with fragile wires, during the process. Your brain’s activity generates minute electrical impulses that are detected by the electrodes. The charges are enhanced, and they can be shown as a line graph on the display of a computer or as an image that is possible to print on paper.
The reading is then explained by your doctor. About one hundred pages of activities are routinely evaluated by your healthcare professional during an EEG.
Your doctor will consider the core waveform while also examining brief flashes of energy and reactions to stimuli like lights flashing. Related practises that may also be used including evoked potential assessments.
These types of studies track the changes in electrical activity in the brain that occur in response to auditory, visual, or tactile stimuli.
Uses of EEG (electroencephalogram) test?
Several different kinds of brain diseases are evaluated using the EEG. Seizure activities tend to show up as fast-spiking waves during the EEG when epilepsy is diagnosed. According to how big and where the lesion is, individuals who have cerebral lesions, which can be caused by tumours or strokes, might exhibit EEG waves that are particularly slow.
Other conditions that affect the functioning of the brain, such as Alzheimer’s
illness, narcolepsy, and psychoses, are also detectable using this test. The general electrical functioning of the brain can also be assessed using the EEG test (for instance, to assess brain injury, drug intoxication, or the degree of damage to the brain in unconscious individuals). In addition, an EEG can be used during surgery to monitor blood flow to the brain. There can be additional reasons why your doctor advises getting an EEG test.
Additionally, EEG test can assess the severity of disorders affecting the brain, including;
- Dementia
- Injury to the brain
- Encephalitis
- Tumours
- Head injuries
- Sleep disorders
- Brain infection
- Brain haemorrhage
- Degeneration of brain tissue
- Hormonal issues that damage the brain’s tissue
- Disorders of CNS (Central nervous system)
EEG tests assist in determining the origins of symptoms like;
- Syncope (fainting)
- Loss of memory
- Confusion
- Seizures
- Signs of metabolic disorders on the brain’s tissue
Types of EEG test
Routine EEG – The routine electroencephalogram (EEG) is an examination of neurophysiologic activity and is frequently carried out to identify and keep track of several disorders that impact the brain. With routine EEG, complicated neurological signals are obtained, and used to evaluate clinically significant aspects using visual evaluation as the basis for the diagnostic procedure in epileptic patients.
Prolonged EEG – A prolonged EEG scan typically lasts an hour. A prolonged EEG provides your doctor with more data than a routine EEG. An extended EEG scan may be used by your doctor to identify or treat issues related to seizures. Video assistance is used in prolonged EEG scans.
Video EEG – Throughout your EEG scan, the technician films you on camera. When you experience a seizure or another brain incident, video recording enables your healthcare professional to observe and hear what you are experiencing. This examination may also be termed by your provider as EEG telemetry, EEG monitoring or video EEG monitoring.
Ambulatory EEG – Ambulatory EEG tests take up to three days. Ambulatory EEG tests can be done at home or in an EEG monitoring centre. A tiny EEG recorder receives electrical signals from electrodes throughout an ambulatory EEG. While the device monitors your brain activities, you’ll be able to generally do your everyday activities. If you experience a seizure or any occurrence that your doctor wants to record, you or a family member may push the button on the device.
Sleep EEG – While you’re sleeping, a technician conducts an EEG test. If a routine EEG doesn’t provide enough details, medical professionals may request sleep EEGs. You could undergo a sleep examination at a sleep disorders centre to check for sleep disorders.
Preparation required for EEG (electroencephalogram) test
Everything you must do before the examination should be explained to you by your healthcare practitioner. Here is an overview of common tasks you might be requested to follow. They include;
- You can ask queries after your doctor guides you through the entire process of the EEG test.
- You will be required to sign an agreement approving the EEG test. If something on the form is unclear, thoroughly read it and ask queries.
- The evening before the test, shampoo your hair but avoid the use of conditioner. Avoid using any hair products, including gels or sprays.
- Inform your healthcare practitioner of all prescription, non-prescription, and herbal products you are consuming before the EEG test.
- Your doctor can instruct you to stop taking any medications that might affect the test. Do not discontinue taking medications unless talking to your doctor.
- For eight to twelve hours before the test, refrain from consuming any foods or beverages which include caffeine.
- Pay attention to whatever instructions your doctor provides you for getting less sleep before the EEG test. You may be required to sleep for some EEG tests (sleep EEG), but not others.
- Avoid fasting before the EEG exam because it can result in low blood sugar, which can alter the results of the EEG.
What to expect after the EEG test?
The technician takes off the electrodes. You shouldn’t experience any adverse effects following the EEG test if you avoided using a sedative. You might be able to resume your regular schedule after the EEG test. If you took a sedative, you will take some time to resume your normal activities before the sedative effect starts to disappear. Make arrangements for a ride home. When you get home, take a nap till the sedative effects completely disappear.
Risks of EEG test
The EEG test is been practised for a long time and is considered as harmless. The examination is painless. Brain activity is captured by the electrodes. They don’t cause any sensation at all. Additionally, there is no chance of getting an electric shock.
An EEG test can occasionally trigger seizures in an individual with a seizure illness. This is an outcome of the potential deep breathing exercises or light flashes involved in EEG tests. Your healthcare professional will treat any seizures you experience right away. Depending on the particular health issue you have, there can be additional hazards. Before the treatment, make sure to discuss concerns you may have with your healthcare professional.
An EEG test’s reading may be affected by particular events or causes. These comprise;
- Fasting-related hypoglycemia, or low blood sugar.
- The motion of the entire body or the eyes while the EEG scan is performed.
- Lights, especially those that are brilliant or flashy.
- Some drugs, like sedatives.
- Caffeine-containing beverages, such as cola, tea, and coffee.
- Use of hair spray and oily hairs
