Intracranial EEG (iEEG) Diagnostic Pathology Test - Everything You Need to Know

Intracranial EEG, or iEEG, is a diagnostic pathology test that involves the insertion of electrodes directly into the brain to monitor electrical activity.

This test is typically used in cases of epilepsy where traditional non-invasive methods such as scalp EEG have not provided enough information.

Intracranial EEG monitoring allows for more precise localization of seizure focus within the brain, aiding in the diagnosis and treatment of epilepsy.

This procedure involves the placement of electrodes on the surface of the brain or deep within brain structures to record neural signals directly.

The process of brain electrode placement for iEEG involves surgically implanting electrodes into specific regions of the brain to monitor electrical activity.

This invasive procedure provides detailed information about cortical activity and helps in identifying abnormal brain patterns associated with seizures.

iEEG for epilepsy is crucial in cases where traditional scalp EEG has not been able to pinpoint the exact location of seizure onset.

By directly monitoring brain activity, iEEG offers valuable insights into the brain's functioning and helps in planning surgical interventions for patients with drug-resistant epilepsy.

In comparison to scalp EEG, which records electrical activity from the surface of the scalp, iEEG provides more accurate and detailed information about brain activity.

This precision is essential in identifying the seizure focus and determining the most effective treatment options for patients with epilepsy.

What is the Purpose of Performing an Intracranial EEG (iEEG) Test?

The primary purpose of performing an intracranial EEG test is to localize the seizure focus within the brain accurately. This information is crucial for determining the most appropriate treatment options for patients with epilepsy.

Intracranial EEG monitoring is also used to assess cortical activity and detect abnormal brain patterns that may be associated with seizures. This data is essential for surgical planning and guiding interventions to control epileptic seizures effectively.

In cases where non-invasive diagnostic methods have not provided conclusive results, iEEG offers a more comprehensive evaluation of brain activity. This detailed information helps neurologists and neurosurgeons make informed decisions about the management of epilepsy.

By recording neural signals directly from the brain, iEEG allows for real-time monitoring of electrical activity during seizures. This provides valuable insights into the dynamics of seizure onset and propagation, aiding in the localization of the seizure focus.

Overall, the purpose of performing an intracranial EEG test is to improve the diagnostic accuracy of epilepsy, facilitate surgical planning, and optimize treatment outcomes for patients with drug-resistant seizures.

What are the Costs of Intracranial EEG (iEEG) Tests in India?

The cost of intracranial EEG tests in India can vary depending on several factors, including the hospital or clinic where the procedure is performed, the complexity of the case, and the number of electrodes used for monitoring.

On average, the cost of an iEEG test in India ranges from INR 50,000 to INR 2,00,000, depending on the duration of monitoring and the level of expertise required for data interpretation.

Factors that can influence the cost of iEEG tests in India include:
The hospital or clinic's reputation and location
The number of electrodes used for monitoring
The duration of monitoring required
Additional services such as anesthesia and post-operative care

In comparison to other diagnostic tests for epilepsy, iEEG may be more expensive due to the invasive nature of the procedure and the specialized equipment and expertise required for accurate data interpretation.

It is essential for patients to discuss the cost of iEEG tests with their healthcare provider and insurance company to understand the financial implications of the procedure and explore potential coverage options.

What is the Normal Range and All Values of Intracranial EEG (iEEG)?

The normal range of intracranial EEG values varies depending on the type of brain activity being measured and the location of the electrodes within the brain.

In general, the electrical activity recorded during iEEG is characterized by specific patterns and frequencies that indicate normal brain function.

During an iEEG test, various values are measured, including:

Amplitude: the height of the electrical signals
Frequency: the number of oscillations per second
Duration: the length of time of each electrical event
Morphology: the shape and pattern of the electrical signals

A table showing the normal ranges of intracranial EEG values:

Values	Normal Range	Meaning
Amplitude	50-100 µV	Normal brain activity
Frequency	0.5-70 Hz	Normal oscillations
Duration	100-500 ms	Normal electrical events
Morphology	Regular patterns	Healthy brain function

Purpose
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FAQ's

Frequently Asked Questions

What is the Wada test used for?

The Wada test is used to determine which side of the brain is responsible for language and memory functions before epilepsy surgery.

What Do High Intracranial EEG (iEEG) Levels Indicate?

High intracranial EEG levels can indicate abnormal brain activity, such as epileptic seizures or other neurological disorders. These elevated levels of electrical signals may be associated with an increased risk of seizure onset and propagation in patients with epilepsy.

What Do Low Intracranial EEG (iEEG) Levels Indicate?

Low intracranial EEG levels may indicate reduced brain activity or abnormal neural function in patients with epilepsy. These decreased levels of electrical signals could be associated with seizure suppression, cortical inhibition, or other neurological conditions.

How does the Wada test help in epilepsy surgery planning?

The Wada test helps in epilepsy surgery planning by determining which side of the brain is responsible for language and memory functions to minimize the risk of post-surgery complications.

What are the risks associated with the Wada test?

The risks associated with the Wada test include stroke, seizure, and allergic reactions to the medications used during the procedure.

How is the Wada test performed on patients?

During a Wada test, a small catheter is inserted into the patient's groin to inject medication that temporarily numbs one side of the brain, allowing doctors to assess language and memory functions while the patient is awake.

How does the Wada test assess language and memory functions?

During the Wada test, a doctor injects a drug into one side of the brain to temporarily numb it while testing language and memory functions on the other side. This helps identify which side of the brain controls these functions.

Is sedation required during the Wada test?

Yes, sedation is typically used during the Wada test to keep you comfortable and still during the procedure.

What are the alternatives to the Wada test for assessing brain function?

Alternatives to the Wada test for assessing brain function include functional MRI (fMRI), positron emission tomography (PET) scans, and neuropsychological testing.

How long does the Wada test take?

The Wada test typically takes about 1 to 2 hours to complete.

What does an abnormal result on the Wada test indicate?

An abnormal result on the Wada test may indicate that the side of the brain being tested is responsible for important functions like language and memory.

How is the Wada test used to evaluate the side of the brain responsible for language?

The Wada test involves temporarily numbing one side of the brain to assess language and memory functions. This test helps determine which side of the brain controls language to plan for surgery or treatment.