elektroenkefalographyssa

Electroencephalography (EEG) is a non-invasive technique for recording the electrical activity of the brain. It uses electrodes placed on the scalp (and sometimes on the cortex with invasive methods) to measure voltage fluctuations produced by neuronal activity. EEG provides a real-time measure of brain function and is widely used in clinical diagnosis, research, and monitoring.

History and principles: Developed by Hans Berger in the 1920s, EEG has evolved into a standard tool for detecting abnormal brain activity. The recorded electrical signals reflect the summed activity of large groups of neurons and are analyzed in the time domain (waveforms) and frequency domain (brain rhythms).

Procedure and interpretation: The common approach uses the international 10-20 system for electrode placement, ensuring standardized coverage of the cerebral cortex. Recordings are performed in a quiet environment with minimized artifacts from movement, blinking, or muscle activity. Data are inspected for patterns such as spikes, sharp waves, or rhythmic activity, and may be supplemented by event-related potentials (ERPs) or sleep EEG protocols.

Applications and limitations: EEG supports diagnosis and management of epilepsy, encephalopathy, sleep disorders, and coma prognosis. It offers excellent temporal resolution but limited spatial localization, and interpretation requires expertise. Artifacts, impedance at the electrode-skin interface, or medications can affect signals.

Language note: The term elektroenkefalography is the Finnish form for electroencephalography; elektroenkefalographyssa would be the locative form meaning 'in electroencephalography.' The English term EEG is widely used in international contexts.