EEG Medical Terminology

EEG Medical Terminology

• Electrocorticography: Involves direct recording of electrical activity from the cerebral cortex using implanted electrodes during or after surgery.

• Frequency: Measured in Hertz (Hz), denoting the number of complete cycles of repetitive waves per second.

• Cycles: Defined as a complete sequence of changes in a wave or complex before it repeats.

• Cycles per second: Another term for frequency, commonly referred to as Hertz (Hz).

Frequency Bands

• Alpha: Frequency band in EEG between 8-13 Hz, associated with relaxed wakefulness.

• Beta: Faster EEG frequency band above 13 Hz, linked to alertness and active thinking.

• Delta: Frequency band below 4 Hz, commonly observed during deep sleep.

• Theta: Frequency band from 4 Hz to less than 8 Hz, associated with light sleep and relaxation.

Brain Topography

• Topography: Refers to the spatial distribution of waveforms on the brain's surface, indicating their location (frontal, temporal, parietal, occipital) and pattern characteristics (lateralized, focal, diffuse).

• Anterior: Refers to the front portion of the brain.

• Posterior: Refers to the back portion of the brain.

• Ventral: Describes the front side of the brain.

• Dorsal: Describes the back side of the brain.

• Frontal: Pertains to the front part of the brain, including cognitive functions.

• Central: Relates to the area surrounding the central sulcus, a significant landmark in brain anatomy.

• Temporal: Connected to the temporal lobe, involved in auditory processing.

• Parietal Lobe: Located posterior to the central area, above the occipital region.

• Occipital: The back part of the brain responsible for visual processing.

Waveforms and Patterns

• Complex: A waveform consisting of multiple frequencies and morphologies.

• Paroxysmal slowing: Also referred to as FIRDA, marked by sudden changes in brain activity.

• Electrodecremental: Refers to a rapid loss of amplitude with a quick return to the previous brain activity pattern.

• Attenuation: Signifies a reduction in the amplitude of EEG activity.

Lateralization and Localization

• Lateralized: Activity occurring in only one hemisphere of the brain.

• Bilateral: Activity occurring across both hemispheres.

• Contralateral: Involves the opposite side of the head or body from where the activity is observed.

• Focal: Activity localized to a specific brain area.

• Multifocal: Involves several independent areas of brain activity, such as multifocal paroxysmal spike discharges.

• Generalized: Activity present simultaneously across all recording electrodes.

Electrode and Recording Techniques

• Montage: An organized configuration of electrode derivations collected simultaneously during EEG.

• Derivation: A pair of electrodes functioning as a single channel for EEG recording.

• Dipole: Characterized by two equal and opposite charges separated by a short distance.

• Horizontal dipole: When surface electrodes capture both the positive and negative ends of a generator in EEG.

Anatomical Orientation

• Sagittal: Pertaining to the plane dividing the body into right and left halves.

• Parasagittal: Refers to EEG planes running parallel to the midline.

• Transverse: Describes the horizontal plane across the head from left to right.

• Vertex: The topmost point of the skull, represented by the electrode area Cz in EEG.

EEG Activity and Artifacts

• Background activity: Represents normal EEG patterns observed in resting patients during asymptomatic periods, with eyes closed.

• Artifact: Any extraneous signals in an EEG record resulting from non-cerebral sources, such as EKG, pulse, or eye movements.

• PLEDS: Abbreviation for periodic lateralized epileptiform discharges, indicative of specific brain activity patterns.

Test your knowledge of key medical terminology related to electroencephalography (EEG). This quiz covers essential terms and definitions that are crucial for understanding EEG procedures and practices. Perfect for students and professionals in the medical field.