An Electroencephalogram (EEG) is a non-invasive neurophysiological test that measures and records the electrical activity of the brain. It is commonly used to evaluate and diagnose various neurological disorders and conditions. Here are some key points about EEG:

Purpose:

• Diagnosis: EEG is often used to diagnose conditions such as epilepsy, sleep disorders, and certain neurological disorders.
• Research: EEG is also utilized in research to study brain function and understand various aspects of brain activity.

Procedure:

• During an EEG, electrodes are attached to the scalp using a conductive gel or paste. These electrodes detect the electrical signals generated by neurons in the brain.
• The electrodes are strategically placed to record brain activity from different regions.

Recording and Patterns:

• EEG recordings typically display brain wave patterns, which are categorized into different frequency bands such as alpha, beta, delta, and theta waves.
• Different patterns and abnormalities in the EEG can provide valuable information about the brain's function and help in the diagnosis of neurological disorders.

Frequency Bands:

• Alpha Waves (8-13 Hz): Predominantly seen in the occipital region, associated with a relaxed and wakeful state.
• Beta Waves (14-30 Hz): Found in the frontal and parietal regions, associated with active thinking and concentration.
• Theta Waves (4-7 Hz): Typically seen in the hippocampus, associated with deep relaxation and light sleep.
• Delta Waves (less than 4 Hz): Predominantly seen in deep sleep, and their presence during wakefulness can indicate certain neurological disorders.

Clinical Applications:

• Epilepsy: EEG is crucial in diagnosing and monitoring epileptic seizures. Specific patterns in the EEG can help identify the type and location of seizure activity.
• Sleep Disorders: EEG is used to study sleep patterns and diagnose disorders like insomnia, sleep apnea, and narcolepsy.
• Brain Injury: It can be used in cases of head trauma to assess brain function and detect abnormalities.

Ambulatory EEG:

In addition to traditional in-office EEG, there are ambulatory EEGs that allow patients to move around during the recording period. This can provide more natural and comprehensive data, especially for conditions that may not occur during a brief in-office session.

EEG is a valuable tool in neurology, providing important insights into brain function and aiding in the diagnosis and management of various neurological conditions.