What is EEG (Electroencephalogram)?

An electroencephalogram (EEG) is a non-invasive diagnostic test that measures the electrical activity of your brain. Think of it like listening in on the conversations between your brain cells. These conversations happen through tiny electrical signals, and the EEG picks up on these signals using small metal discs (electrodes) placed on your scalp. The EEG doesn't send any electricity into your brain; it only records the activity that's already there.

The electrical activity is recorded as wavy lines on a graph. These lines are brainwaves, and their patterns can tell doctors a lot about how your brain is functioning. Doctors, particularly neurologists, use the EEG to diagnose and monitor a wide range of neurological conditions. It's a painless procedure and provides valuable information for guiding treatment decisions.

Key Facts:

Non-invasive: No needles or surgery are involved.
Painless: You won't feel any discomfort during the test.
Measures brain activity: Records electrical signals produced by your brain.
Diagnostic tool: Helps identify and monitor various neurological conditions.
Safe procedure: Minimal risks are associated with the test.

Why is EEG (Electroencephalogram) Performed?

An EEG is a valuable tool for diagnosing and monitoring various neurological conditions. Your doctor might recommend an EEG if you're experiencing any of the following:

Main Conditions/Indications:

Epilepsy and seizures: To identify abnormal electrical activity that causes seizures and determine the type of seizure.
Sleep disorders: To evaluate brain activity during sleep and identify sleep-related problems like insomnia, sleep apnea, or narcolepsy.
Brain injuries: To assess the extent of brain damage after a head injury or trauma.
Brain tumors: To help locate the tumor and assess its impact on brain function.
Stroke: To evaluate brain activity and the extent of damage caused by a stroke.
Altered consciousness: To assess brain function in individuals in a coma or with unexplained unconsciousness.
Memory problems/dementia: To detect changes in brain wave patterns associated with memory loss and cognitive decline.
Brain infections/inflammation (encephalitis): To help diagnose and monitor brain infections or inflammation.
Unexplained fainting or dizziness: To rule out neurological causes for these symptoms.
To monitor brain activity during brain surgery.
Diagnosing non-convulsive status epilepticus (NCSE) in ICU patients with altered consciousness.

When Doctors Recommend It:

Doctors often recommend an EEG when symptoms suggest a potential problem with brain function. This may include:

Sudden, unexplained episodes of unusual behavior.
Recurring headaches accompanied by neurological symptoms.
Changes in mental status or cognitive abilities.
Unexplained loss of consciousness.
Suspected brain injury or stroke.

Preparation for EEG (Electroencephalogram)

Proper preparation is crucial for obtaining accurate EEG results. Here's what you need to do:

Essential Preparation Steps:

Wash Your Hair: Wash your hair thoroughly the night before the test using shampoo only. Avoid using conditioners, hair oils, gels, or hairspray, as these can interfere with electrode contact.
Medication Disclosure: Inform your doctor about all medications you are currently taking, including prescription drugs, over-the-counter medications, and herbal supplements. Your doctor will advise you on whether to continue or discontinue any medications before the test. Do not stop taking any medication without consulting your doctor first.
Avoid Caffeine: Avoid caffeine-containing foods and drinks (tea, coffee, cola, chocolate) for at least 8-12 hours before the test. Caffeine can affect brain activity and distort the EEG results.
Eat Before the Test: Have a meal before the test to avoid low blood sugar (hypoglycemia), which can also affect brain activity.
Sleep Deprivation (for Sleep EEG): If you are scheduled for a sleep EEG, your doctor might instruct you to limit your sleep the night before. Adults may be asked to sleep only 4-5 hours, and children 5-7 hours. This helps to induce sleep during the test and capture relevant brain activity.
Relax: Try to relax and stay calm before the test. Anxiety can sometimes affect brain wave patterns.

India-Specific Tips:

Fasting: Unless specifically instructed by your doctor, fasting is generally not required for a routine EEG. Confirm with your doctor regarding fasting, especially if you have diabetes.
Documents: Carry your doctor's referral letter, any relevant medical records (previous EEG reports, MRI scans), and your Aadhar card or other identification.
PC-PNDT Act: The Pre-Conception and Pre-Natal Diagnostic Techniques (PC-PNDT) Act has no relevance to EEG procedures. This act pertains to prenatal sex determination, which is unrelated to EEG.

What to Expect:

The EEG technician will explain the procedure to you.
You will be asked to lie down or sit comfortably in a chair.
Electrodes will be attached to your scalp using a special paste.
You will be asked to relax and stay still during the recording.

The EEG (Electroencephalogram) Procedure

The EEG procedure is straightforward and generally takes about 30-60 minutes for a routine study. Here's a step-by-step explanation:

Step-by-Step:

Preparation: You will lie down on a bed or sit comfortably in a reclining chair.
Electrode Placement: The EEG technician will measure your head and mark specific locations on your scalp. These locations correspond to different areas of the brain. The scalp is gently cleaned to ensure good electrode contact.
Electrode Attachment: Small, flat metal discs (electrodes) are attached to your scalp using a special conductive paste. The paste helps the electrodes pick up the electrical signals from your brain. The electrodes are connected to an EEG machine via wires.
Baseline Recording: The EEG recording begins with you resting quietly with your eyes closed. This establishes a baseline of your normal brain activity.
Activation Procedures: During the recording, the technician may ask you to perform certain tasks to stimulate brain activity:
- Opening and closing your eyes: This helps to assess your brain's response to visual stimuli.
- Hyperventilation: Taking deep breaths for a few minutes. This can sometimes trigger abnormal brain activity in individuals with certain conditions, such as epilepsy.
- Photic Stimulation: Looking at a flashing strobe light. This can also trigger abnormal brain activity in susceptible individuals.
Video EEG (if required): In some cases, a video camera will record your movements during the EEG. This is called video EEG and helps the doctor correlate any physical symptoms you experience with the brainwave activity recorded on the EEG. This is particularly useful for diagnosing seizures.
Recording Completion: Once the recording is complete, the electrodes are removed from your scalp, and the paste is cleaned off.

Duration, Comfort Level:

A routine EEG typically takes 30-60 minutes.
Ambulatory EEGs (where you wear the device for 24-72 hours) take longer and require more preparation and follow up.
The procedure is generally painless. You may feel a slight coolness or stickiness from the electrode paste.

What Happens During the Test:

During the test, you will be asked to remain still and relaxed. The technician will monitor your brain activity and make notes of any unusual events. If you experience any symptoms during the test, such as dizziness, headache, or a seizure, inform the technician immediately. The technician is trained to handle any complications that may arise during the procedure.

Understanding Results

After the EEG recording is complete, a neurologist will analyze the brainwave patterns. The results are interpreted in the context of your medical history, symptoms, and other diagnostic tests.

Normal vs. Abnormal Ranges:

Normal EEG: A normal EEG shows brainwave patterns that are appropriate for your age and state of alertness (awake or asleep). The brainwaves have a characteristic frequency and amplitude (height).
Abnormal EEG: An abnormal EEG shows brainwave patterns that are outside the normal range. This may include:
- Spikes or sharp waves: These can indicate seizure activity.
- Slowing of brainwaves: This can indicate brain damage, inflammation, or other neurological problems.
- Asymmetry of brainwaves: This can indicate a localized problem in one area of the brain.

What Results Mean:

The EEG results can help your doctor diagnose the cause of your symptoms and guide treatment decisions. For example:

Epilepsy: An EEG can help confirm the diagnosis of epilepsy and identify the type of seizures you are experiencing. It can also help determine the location of the seizure focus in the brain.
Sleep Disorders: An EEG can help diagnose sleep disorders such as insomnia, sleep apnea, and narcolepsy by recording brain activity during sleep.
Brain Injury: An EEG can help assess the severity of brain damage after a head injury and monitor recovery.
Brain Tumors: An EEG can help locate brain tumors and assess their impact on brain function.
Other Conditions: An EEG can also help diagnose other neurological conditions such as encephalitis, stroke, and dementia.

Next Steps:

After reviewing the EEG results, your doctor will discuss them with you and explain their implications. Depending on the results, your doctor may recommend further tests, such as an MRI or CT scan, to get a more detailed picture of your brain. Your doctor will also discuss treatment options with you, which may include medication, surgery, or lifestyle changes.

Costs in India

The cost of an EEG test in India can vary depending on several factors, including the location, the type of facility (government vs. private), and the complexity of the test.

Price Range in ₹ (Tier-1, Tier-2 Cities):

Tier-1 Cities (e.g., Mumbai, Delhi, Bangalore, Chennai): ₹2,000 - ₹5,000
Tier-2 Cities (e.g., Pune, Ahmedabad, Hyderabad, Kolkata): ₹1,500 - ₹3,500

Government vs. Private:

Government Hospitals: EEG tests are typically more affordable in government hospitals, ranging from ₹1,000 to ₹2,500.
Private Centers: Private hospitals and diagnostic centers generally charge more, ranging from ₹2,500 to ₹5,000 or more, depending on the facilities and technology used. Ambulatory EEGs are significantly more costly.

Insurance Tips:

Check with your health insurance provider to see if EEG tests are covered under your policy. Many health insurance plans in India cover diagnostic tests like EEG, but the extent of coverage may vary.
Some insurance companies may require pre-authorization for EEG tests, so it's best to check with them beforehand.

How Ayu Helps

Ayu helps you manage your health records efficiently. You can:

Store EEG results digitally: Securely store your EEG reports and other medical records in one place.
Track over time and share: Monitor changes in your EEG results over time and easily share your records with doctors via a QR code, ensuring seamless communication and informed decision-making.

FAQ

Here are some frequently asked questions about EEG:

Q1: Is an EEG painful?

A: No, an EEG is a painless procedure. You may feel a slight coolness from the electrode paste, but the electrodes themselves do not cause any pain or discomfort.

Q2: Are there any risks associated with an EEG?

A: EEGs are generally very safe. Rarely, hyperventilation or flashing lights during the test can trigger a seizure in individuals with epilepsy. However, the technician is trained to manage this situation.

Q3: How long does an EEG take?

A: A routine EEG typically takes 30-60 minutes. Sleep EEGs and ambulatory EEGs can take much longer.

Q4: How should I prepare for an EEG?

A: Wash your hair the night before the test, avoid caffeine for at least 8 hours, inform your doctor about all medications you are taking, and eat a meal before the test. Follow any specific instructions provided by your doctor.

Q5: What does an abnormal EEG result mean?

A: An abnormal EEG result indicates that there is unusual electrical activity in the brain. This could be due to various conditions, such as epilepsy, sleep disorders, brain injury, or tumors. Your doctor will interpret the results in the context of your medical history and symptoms.

Q6: Can I drive myself home after an EEG?

A: In most cases, you can drive yourself home after an EEG. However, if you were given any sedatives during the test, you will need someone to drive you home. Discuss this with your doctor beforehand.

Q7: How accurate is an EEG?

A: EEG is a valuable diagnostic tool, but it's not always definitive. Sometimes, an EEG can be normal even if you have a neurological condition. Your doctor may recommend further tests to confirm the diagnosis.

Q8: Will the EEG technician tell me the results immediately?

A: No, the EEG technician will not provide the results immediately. The neurologist needs time to analyze the brainwave patterns and write a report. Your doctor will discuss the results with you at a follow-up appointment.

What is EEG (electroencephalogram): Purpose, Procedure & Costs in India