100 years of electroencephalography (EEG) in human medicine
- July 16, 2024
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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100 years of electroencephalography (EEG) in human medicine
Sub: Science and tech
Sec: Health
Context:
- Electroencephalography(EEG) has completed 100 years of its discovery and still remains a crucial tool for understanding the brain.
What is EEG?
- EEG stands for electroencephalography.
- It is a test performed to detect abnormalities in your brain waves, or in the electrical activity of your brain.
- Neurons in the brain perform various functions by moving electrically charged particles such as ions.
- The movement of these particles gives rise to electrical activity that a health worker can use an EEG test to visualize.
How does an EEG test work?
- During an EEG, electrodes are pasted onto the scalp of the patient.
- These are small metal disks with thin wires and detect tiny electrical charges that result from the activity of brain cells.
- These charges are amplified and appear as a graph on a computer screen or as a recording that may be printed out on paper.
- Health workers are typically interested in two types of data in the graph:
- The voltage (measured in millionths of a volt).
- The frequency of the variations (measured in hertz).
- The EEG procedure is usually carried out by a highly trained specialist, called a clinical neurophysiologist.
- Volume conduction refers to the movement of electrical activity through this three-dimensional volume. It also stands for the fact that the electrical activity is produced in one place whereas the detectors that detect it are located at some distance.
- EEG is better than other diagnostic devices at tracking relatively rapid electrical activity in the brain, in the order of milliseconds.
What is the significance of EEG?
- An EEG can be used to help diagnose and monitor a number of conditions affecting the brain.
- The main use of an EEG is to detect and investigate epilepsy, a condition that causes repeated seizures.
- In research, scientists use EEG for neuroscience, cognitive psychology, neurolinguistics, and neuromarketing studies and to develop brain-computer interfaces.
- An EEG might also be helpful for diagnosing or treating the following disorders:
- Brain tumor
- Brain damage from head injury
- Brain dysfunction that can have a variety of causes (encephalopathy)
- Inflammation of the brain (encephalitis)
- Stroke
- Sleep disorders
Shortcomings of EEG:
- EEG is biased towards electrical signals generated closer to the surface of the cortex, and significantly so towards currents generated by neurons’ dendrites and against those generated by the axons.
- To overcome these and other challenges, researchers have used EEG together with other tests, like magnetic resonance imaging (MRI), and have developed sophisticated data acquisition, processing, and reconstruction methods.