EEG

EEG (Electroencephalography)

Electroencephalography (EEG) is a neurophysiological research method that records the electrical activity of the brain. It is a safe and non-invasive diagnostic tool used to detect various central nervous system (CNS) diseases, as well as to monitor brain activity in real-time. EEG is an important tool in neurology and psychiatry and is applied in a range of clinical cases such as epilepsy, neurological disorders, sleep disorders, and many others.

Principle of EEG

EEG is based on measuring the electrical activity of brain neurons using special electrodes attached to the patient's scalp. The brain generates electrical signals during its activity, which can be recorded and displayed as graphs on a computer screen. Electrical impulses generated by neuron activity are transmitted through brain structures and accumulate on the scalp. Using electrodes, this activity can be recorded and analyzed to detect deviations from normal.

The electrical activity of the brain is divided into several types of waves that can vary in frequency and amplitude. Based on these characteristics, specialists can assess the functional state of the brain and detect possible pathologies.

Types of EEG

• Standard EEG — the main method used to record normal brain activity at rest. This type of study is used to detect epileptic activity, sleep disturbances, and other deviations from the norm.
• EEG with load — a method where the patient performs certain tasks or is exposed to various stimuli (such as light or sound). These tasks help identify hidden disorders or epileptic foci.
• Long-term EEG (monitoring) — used for prolonged observation of brain activity, usually in a hospital setting. This method helps monitor patients with epilepsy or other CNS disorders and is also used to monitor patients in intensive care units.
• EEG during sleep — used to assess brain activity during sleep. This method is important for diagnosing sleep disorders such as apnea, insomnia, or narcolepsy.
• EEG with video monitoring — combines standard EEG research with video observation. This is especially useful for diagnosing epilepsy, where it is important to record possible epileptic seizures and their relationship with changes in brain activity.

Indications for EEG

EEG is used for the diagnosis and monitoring of various diseases and conditions, including:

• Epilepsy and epileptic disorders — EEG is the gold standard in epilepsy diagnosis. It helps detect foci of pathological activity in the brain that may cause seizures.
• Sleep disorders — EEG assists in diagnosing sleep disorders such as insomnia, apnea, restless leg syndrome, and narcolepsy.
• Neurological diseases — such as stroke, brain tumors, neurodegenerative diseases (e.g., Alzheimer's disease), circulatory disorders, and acute and chronic traumatic brain injuries.
• Psychiatric diseases — EEG can be used to assess brain activity in depression, schizophrenia, bipolar disorders, and other mental illnesses.
• Monitoring the condition of patients in intensive care — EEG helps assess the functional state of the brain in patients with critical conditions such as coma, epileptic status, or encephalopathy.
• Evaluation of treatment effectiveness — EEG is used to monitor the treatment of epilepsy, sleep disorders, and other neurological diseases, helping doctors adjust therapeutic approaches.

How is EEG performed?

The EEG procedure does not require special preparation and is painless. Here is how the process goes:

1. Preparation of the patient — before the procedure, all metallic objects on the head (such as earrings, pins, glasses) must be removed, and the hair should be clean and dry.
2. Attachment of electrodes — small electrodes are attached to the patient's scalp using special gel, which improves signal conductivity. The electrodes are placed in a specific system at various points on the head.
3. Recording process — during the study, the patient sits or lies in a comfortable position. The electrodes record the brain's electrical activity, which is displayed on the computer screen.
4. Completion of the study — the process typically takes between 20 to 40 minutes, depending on the type of study. The patient can resume normal activities immediately after the procedure.

Advantages of EEG

• Safety — EEG is an entirely safe procedure that does not use radiation or invasive methods. This makes it available to children, pregnant women, and the elderly.
• Non-invasiveness — the procedure is painless and does not require surgical intervention, making it comfortable for the patient.
• High informativeness — EEG allows for the detection of functional changes in the brain at early stages of diseases, helping to start treatment promptly.
• Accessibility and simplicity — EEG is available in most medical institutions and does not require extensive preparation, making it an effective and fast diagnostic method.

Limitations of EEG

Despite its numerous advantages, EEG has some limitations:

• Often requires supplementation with other methods — in some cases, EEG cannot provide a complete picture of the disease, and additional diagnostic methods such as magnetic resonance imaging (MRI) or computed tomography (CT) may be necessary.
• Inability to assess the brain's structure — EEG only analyzes the functional state of the brain and does not provide information about its anatomical structure. For this, other research methods are required.

Conclusion

EEG is a valuable and versatile research method that allows real-time assessment of brain activity and the detection of various central nervous system pathologies. Timely diagnosis using EEG can significantly improve treatment outcomes and help monitor the condition of patients with various diseases. It is a painless and accessible method that remains a crucial tool in neurology, psychiatry, and other fields of medicine.