🔹 1. What is EEG?
An EEG (electroencephalogram) is a medical test that measures the electrical activity of the brain using small, flat metal discs called electrodes that are attached to the scalp.
The EEG machine records these brain wave patterns and displays them as wavy lines on a computer or paper. It is a non-invasive, painless, and safe method widely used in hospitals and clinics.
🔹 2. Purpose and Use
EEG is used to diagnose and monitor brain-related conditions, including:
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Epilepsy and seizures
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Sleep disorders (e.g., insomnia, sleep apnea, narcolepsy)
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Brain injuries (trauma, swelling, coma)
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Brain tumors
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Stroke
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Encephalitis (brain inflammation)
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Monitoring during anesthesia or brain surgery
EEGs can also help in brain death confirmation and neurological research.
🔹 3. How It Works
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Electrodes are placed on the scalp using a cap or adhesive.
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These electrodes detect tiny electrical signals produced by the neurons (brain cells).
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The signals are amplified and sent to the EEG machine, which converts them into graphical waves.
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Different types of brain activity (awake, asleep, seizure) produce distinct wave patterns.
🔹 4. Types of EEG Tests
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Routine EEG (20–40 minutes)
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Sleep EEG (done during sleep or with sedatives)
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Ambulatory EEG (worn for 24–72 hours during daily activities)
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Video EEG Monitoring (records brain activity and behavior simultaneously, often in epilepsy diagnosis)
🔹 5. Origin and History
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The first human EEG was recorded by Hans Berger, a German psychiatrist, in 1924.
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Berger discovered alpha waves (Berger waves), revolutionizing neuroscience.
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Over time, EEG machines evolved from analog paper recordings to digital systems with software analysis.
🔹 6. Modern EEG Technology
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Digital EEG machines can now perform automatic pattern recognition.
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Used in telemedicine, ICU monitoring, and neurofeedback therapy.
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Combined with imaging (EEG + MRI) for more precise diagnosis.
🔹 7. Advantages
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Non-invasive and safe.
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Real-time monitoring.
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Valuable in epilepsy and brain function analysis.
🔹 8. Limitations
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EEG only measures surface-level activity (not deep brain structures).
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Results can be affected by movement, muscle activity, or external interference.
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Requires expert interpretation.
📌 Summary
The EEG machine is a vital neurological tool for recording the brain's electrical signals. Since its invention in the 1920s, it has become indispensable in diagnosing epilepsy, sleep disorders, and brain function, and continues to evolve with modern medical technology.