What is an EEG, and How Is It Used to Diagnose Neurological Disorders?

Electroencephalography (EEG) is a non-invasive diagnostic test that records the brain’s electrical activity. By detecting abnormalities in brain waves, EEG provides valuable insights into various neurological conditions.

What Is an EEG?

An EEG is a diagnostic test that uses small electrodes attached to the scalp to measure electrical activity in the brain. Your brain cells, or neurons, communicate through electrical impulses, and these signals create patterns that can be recorded. These patterns reveal information about your brain’s overall function and potential abnormalities.

How Does an EEG Work?

During an EEG:

Electrodes are placed on the scalp using a special adhesive or cap.
These electrodes detect brain wave activity, which is recorded as wavy lines on a computer.
The process is painless and typically takes 30–60 minutes.

The brain’s electrical activity is categorized into different wave types, such as alpha, beta, theta, and delta waves. Any irregularities in these patterns can indicate a neurological condition.

What Is an EEG Used For?

An EEG is widely used in diagnosing and managing various neurological disorders. Below are some of the most common applications:

1. Epilepsy and Seizure Disorders

EEG is the gold standard for diagnosing epilepsy. It helps detect unusual electrical activity in the brain that could indicate seizure disorders.
It also determines the type of epilepsy, aiding in targeted treatment plans.

2. Sleep Disorders

Conditions like insomnia, narcolepsy, and sleep apnea can sometimes be linked to irregular brain activity. EEG can help identify these abnormalities.

3. Brain Tumors and Injuries

EEG detects functional abnormalities caused by brain tumours or head injuries, complementing imaging tests like MRI or CT scans.

4. Dementia and Alzheimer’s Disease

EEG can help assess changes in brain function in patients with cognitive decline, providing early diagnostic clues for conditions like dementia.

5. Stroke

After a stroke, an EEG can monitor brain function to evaluate the extent of the damage and guide rehabilitation efforts.

6. Monitoring Brain Activity During Surgery

Intraoperative EEG is used during brain or spinal surgeries to monitor real-time brain function and ensure safety.

What Happens During an EEG Test?

Here’s what to expect during the procedure:

Preparation

Avoid caffeine and alcohol for 12 hours before the test.
Wash your hair to remove oils, but don’t apply hair products.
Inform your neurologist about any medications you’re taking, as some can affect results.

During the Test

You’ll sit or lie comfortably in a quiet room.
The technician will place electrodes on your scalp.
You may be asked to perform specific tasks, like breathing deeply or to close and open your eyes.

After the Test

You can resume normal activities immediately.
Your neurologist will analyze the EEG results and explain the findings.

How Is an EEG Interpreted?

A neurologist interprets EEG results. The test produces a chart of brain wave patterns that may reveal:

Normal Activity: Indicates healthy brain function.
Abnormal Activity: May point to seizures, brain injuries, or other conditions.

For example:

Spikes or sharp waves may suggest epilepsy.
Slower brain waves might indicate damage from a stroke or tumour.

Are There Any Risks Associated with EEG?

EEGs are safe and non-invasive, with no significant risks. However:

In rare cases, the test might trigger a seizure in people with epilepsy (this is often intentional for diagnostic purposes).
The adhesive used for electrodes may cause mild scalp irritation.

If you have concerns, discuss them with your neurologist before the test.

Benefits of EEG in Diagnosing Neurological Disorders

Early Detection: EEG helps identify conditions early, enabling prompt treatment.
Non-Invasive: It’s painless and doesn’t involve radiation.
Cost-Effective: Compared to other diagnostic tools, EEG is relatively affordable.
Real-Time Monitoring: EEG provides immediate feedback on brain activity, which is useful for acute conditions.

How Is an EEG Used in Diagnosing Neurological Disorders?

An EEG is a versatile diagnostic tool that provides neurologists with critical information about brain function. By capturing the electrical activity of the brain, it helps pinpoint abnormalities that may indicate specific neurological conditions. Here’s how it is used in diagnosing various disorders:

1. Detecting and Classifying Epilepsy

EEG is the most effective tool for diagnosing epilepsy. During a seizure, the brain’s electrical activity becomes erratic, creating distinct patterns on the EEG recording. These patterns help neurologists:

Confirm the diagnosis of epilepsy.
Classify the type of seizures (e.g., generalized or focal).
Determine the affected areas of the brain.

This information is essential for tailoring treatment plans, such as selecting appropriate medications or evaluating the suitability of surgical interventions.

2. Identifying Sleep Disorders

EEG plays a significant role in diagnosing sleep-related neurological conditions, such as:

Narcolepsy: Characterized by sudden sleep attacks and abnormal REM patterns.
Sleep Apnea: While primarily diagnosed through polysomnography, EEG helps assess disrupted brain activity caused by poor sleep quality.

By analyzing brain wave activity during different sleep stages, neurologists can understand how these disorders impact brain function.

3. Diagnosing and Monitoring Brain Tumors and Lesions

Abnormalities in EEG recordings can indicate the presence of brain tumors or lesions that disrupt normal electrical activity. While imaging tests like MRIs or CT scans are crucial for structural analysis, EEG provides complementary functional insights:

Localizing Impacted Brain Regions: Identifies which areas of the brain are affected.
Tracking Changes Over Time: Monitors the progression of neurological symptoms and treatment efficacy.

4. Evaluating Stroke and Brain Injury

A stroke or traumatic brain injury can disrupt the brain’s normal electrical activity. EEG helps in:

Acute Diagnosis: Detecting brain activity irregularities immediately after an event.
Rehabilitation Monitoring: Assessing recovery progress and identifying areas requiring further therapy.

For stroke survivors, EEG can help predict long-term outcomes by measuring the level of brain function in affected areas.

5. Diagnosing Cognitive and Memory Disorders

In patients with cognitive decline, EEG helps identify abnormal brain activity that could signal conditions such as:

Alzheimer’s Disease: Reduced alpha and beta wave activity often correspond to early-stage cognitive impairments.
Other Dementias: Differentiating between types of dementia based on brain wave patterns.

Early diagnosis allows for timely intervention, which can slow disease progression and improve quality of life.

6. Assessing Neurological Impact of Chronic Conditions

Neurological symptoms often arise as complications of chronic illnesses like diabetes or autoimmune diseases. EEG is used to:

Detect peripheral or central nervous system involvement.
Monitor the effects of systemic conditions on brain health.

7. Understanding Unexplained Symptoms

For patients with unexplained symptoms such as fainting spells, dizziness, or chronic headaches, an EEG can rule out or confirm a neurological cause. By identifying disruptions in normal brain wave patterns, it helps neurologists narrow down possible conditions.

8. Guiding Treatment Plans

EEG isn’t just a diagnostic tool—it’s also used to monitor and adjust treatments for neurological disorders. For example:

Epilepsy: Tracking seizure frequency and evaluating the effectiveness of medications.
Deep Brain Stimulation (DBS): Ensuring accurate placement and functionality of electrodes in treatments for movement disorders.
Sleep Disorders: Fine-tuning therapies for conditions like insomnia or restless leg syndrome.

How HNNC Provides EEG and Neurological Disorder Treatment

At Hashwani Neurology & Neurophysiology Clinic (HNNC), we are dedicated to offering cutting-edge diagnostic tools and personalized care for patients facing neurological challenges. Our team of experienced neurologists uses advanced EEG technology to diagnose and treat a wide range of neurological disorders accurately. Whether you’re dealing with seizures, sleep disturbances, or unexplained symptoms, HNNC is here to help.

We understand that navigating neurological conditions can be overwhelming, which is why we take a patient-centred approach.

Contact Us to Learn More About EEG

If you’re experiencing neurological symptoms or have been advised to undergo an EEG, contact HNNC today to schedule a consultation. Our team is here to answer your questions, explain the process, and provide the support you need to take charge of your health.