EEG TERMINOLOGY SET 1 QUESTIONS AND ANSWERS 2023

EEG TERMINOLOGY SET 1 QUESTIONS AND ANSWERS 2023 ELECTROENCEPHALOGRAPHY The process of amplicication, recording and analysis of the electrical potentails of the brain GRAPH instrument GRAPHY PROCESS GRAM THE RECORDING ELECTROENCEPHALOGRAM The EEG recording itself *can be printed or stored on digital media ELECTROENCEPHALOGRAPH The instrument used to amplify and record eletrical potentials of the brain ELECTROCORTICOGRAPHY The recording of electrical activity directly from the surface of the cerebral cortex *during surgery or post surgery (implanted leads) TERMS TO DESCRIBE EEG PATTERNS & WAVES FTMOP Frequency Topography Morphology Occurrence Polarity FREQUENCY *cycles per second STANDARD UNIT OF FREQUENCY IS Hertz *1hz is equal to 1 cycle per sec *the number of complete cycles of repetitive waves or complexes in one sec. CYCLES a complete series of changes undergone by a wave or complex before the series of changes are repeated CYCLE PER SEC *unit of freq also called HZ (Hertz) HERTZ unit of freq. cycles per sec *named after Heinrich Randolf Hertz (german physicst /pioneer radio communications) ALPHA freq. band 8-13 hz BETA freq band above 13 DELTA freq band less than 4 THETA freq band 4 - 8 TOPOGRAPHY distribution of a pattern or waveform over surface of the brain. *where is the pattern located (frontal, anterior, temporal, central, lateralized, generalized, lt or rt) ANTERIOR at or near front POSTERIOR at or near back VENTRAL front DORSAL back FRONTAL situated in or arising from front CENTRAL area of brain around the central sulcus TEMPORAL around the temporal lobe PARIETAL around the parietal lobe *posterior to the central *superior to the occipital SUPERIOR LOCATION above OCCIPITAL posterior portion of the brain *above cerebellum *vision MORHOLOGY form or shape of EEG waves and patterns MONOMORPHIC one dominant patern/rhythm POLYMORPHIC multiple frequencies together creating complex waveforms BIPHASIC waveform having 2 phases or 2 deflections on each side of the baseline TRIPHASIC waveform having 3 phases SINUSOIDAL having a curved shape as in an "S" or sine wave *Alpha is often sinusoidal COMPLEX waveform made up of more than one freq & morphology *EX: spike & slow wave OCCURRENCE in what age group, pt state does the pattern occur How often does the pattern occur (frequently, rarely, periodically, continously, sporadically, paroxysmally) POLARITY negative or positive or neutral value * relates to the polarity convention POLARITY CONVENTION if Grid 1 is more negative or less positive than Grid 2 the deflection is UP if Grid 2 is more negative or less positive than Grid 1 the deflecton is DOWN PAROXYSMAL SLOWING / FIRDA Frontal Intermittent Rhythmic Delta Activity PAROXYSMAL SPIKE AND SLOW WAVE LOOKS LIKE sudden coming and going spike & slow wave ELECTRODECREMENTAL event causing sudden loss of amplitude with abrupt return to the previous pattern ATTENUATION reduction in the amplitude of EEG activity SUPPRESSION attenuation of activity that should be there or is present on the opposite side SYNCHRONOUS pattern that appears over both hemispheres simultaneously with similar timing *both sides, same time SYNCHRONY timing of a patterns apperance HYPERSYNCHRONOUS increase in voltage & rhythmicity of a pattern appearing very regular sinusoidal and high amp ASYNCHRONOUS appearing with different timing over the cerebral hemisphers *non-stimultaneous occurence of EEG activity over regions of the same or opposite side of head SYMMETRY/ SYMMETRICAL same on both sides, *can be symmerty of frequency and amplitude ASYMMETRY OF ASMMETRICAL a change in apperance of a rhythm on one side. *the occurrenc /or lack of a feature on one side *EEG can be asymmetrical because of an addition /suppression on activity over one side PERIODICITY time interval between the occurrence of a wave or pattern, *. A waveform is said to be periodic if it occurs at regular intervals of time REACTIVITY pattern that changes with stimulation .....as in eye opening & attenuation aof alpha in the occipital leads CONTINUOUS seen without interruption DISCONTINOUS seen occasionally interrupted INTERMITTENT happening from time to time with no difinite periodic pattern LATERALIZED occuring only over one hemisphere BILATERAL both sides, in EEG -occurring over both hemispheres UNILATERAL restricted or remaining in one hemisphere as the suppressionis Unilateral CONTRALATERAL relating to the opposite side of the head or body "a contralateral ear reference montage refers leads on one side of the head to the ear on the opposite side. *mu rhythm is attenuated by real or imagined contralateral motor activity" IPSILATERAL on the same side -an ipsilateral ear reference montage refers all leads in Grid 1 to the ear on the same side of the head FOCAL in a clearly delineated area of the brain as in focal temporal spike or focal slowing MULTIFOCAL having several independent foci as in multifocal paroxysmal spike discharges GENERALIZED occuring simultaneously throughout the recording leads. *a discharge can be primarily generalized or secondarily generalized MONTAGE organized combination of electrode derivations recording at the same time on the electroencephalograph DERIVATION one set of 2 electrodes placed into grid 1 and grid 2 (the two inputs) of one channel of the EEG INPUT 1 & INPUT 2 these are the 2 inputs for each channel that record the electrical potential into the differential amplifier of an EEG DIPOLE having two equal and opposite magnetized or eletrically charged poles that are separated by a short distance HORIZONTAL DIPOLE in EEG, when surface electrodes are able to record both negative and positive ends of a generator MONOPOLAR older term not used as much "having one pole" *refers to a montage that's referential...has 1 lead in grid1 that is "considered active" & grid 2 lead is " considered the reference" BIPOLAR "meaning having 2 poles" refers to montages that are "scalp to scalp ' RHYTHMIC having a marked regularly occuring pattern of *activity *feature *frequency range (as in alpha)