Artifacts in EEG recordings can have distinguishing features that help differentiate them from brain-generated activity or other types of artifacts.
1. Compared to
Ocular Artifact:
oDescription: Slow roving eye
movements produce an artifact similar to perspiration artifact.
oCharacteristics:
§Rhythmicity: Involuntary and
repeated horizontal ocular movements occur with a relatively constant period.
§Phase Reversal: Phase reversal
due to the eyes' dipoles, with different field polarities around
frontal-temporal electrodes during lateral eye movements.
§Field
Distribution: Broad, bifrontal field compared to other artifacts like
salt bridge artifact.
2. Compared to Focal
Interictal Epileptiform Discharges:
oDescription: Electrode pop
resembles IEDs but has distinct characteristics.
o Characteristics:
§Field
Distribution: Involves only one electrode without a gradual decrease
in potential amplitude across the scalp.
§Waveform: Steeper rise
and slower fall compared to IEDs.
3. Compared to Ictal
Patterns:
oDescription: Environmental
device artifacts may resemble ictal patterns but have distinguishing features.
o Characteristics:
§Duration: Fixed durations
and regular repetitions compared to evolving patterns in seizures.
§Waveform
Preservation: Highly preserved waveforms in artifacts.
4. Compared to
Periodic Epileptiform Discharges:
oDescription: Environmental
artifacts may have similarities to PEDs but with key differences.
o Characteristics:
§Waveform: Rarely diphasic
or triphasic, unlike PEDs.
§Distribution: Unusual
electrode inclusion and generalized occurrence common in artifacts.
Understanding
these distinguishing features of artifacts is essential for EEG technologists
and clinicians to accurately identify and differentiate artifacts from genuine
brain activity. Proper recognition and interpretation of artifacts contribute
to the quality and reliability of EEG analysis in clinical practice and
research.
Comments
Post a Comment