Tricky Posterior Waves on EEG
Abstract number :
2.019
Submission category :
3. Neurophysiology / 3C. Other Clinical EEG
Year :
2022
Submission ID :
2204143
Source :
www.aesnet.org
Presentation date :
12/4/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:23 AM
Authors :
Janet Lee, MD – University of South Florida; Ushtar Amin, MD – University of South Florida; Selim Benbadis, MD – University of South Florida
Rationale: Prior studies have shown that approximately 25% to 30% of patients previously diagnosed with epilepsy who do not respond to initial antiseizure medications do not have epilepsy (Benbadis SR et al, 2003). This is often due to overreading of an EEG, where a normal EEG is read as abnormal (Amin U et al, 2019), and leads to a misdiagnosis of epilepsy. In order to clarify a potential source of confusion, we reviewed and collected various EEGs with common normal variants and epileptiform patterns that occur in the posterior leads.
Methods: We reviewed and collected scalp EEGs from 2018 to 2022 with common patterns observed in the posterior leads.
Results: Eight examples of normal variants that are commonly seen in the posterior leads on EEG were collected (Figure 1). These include visual evoked potentials, blink artifact, posterior slow waves of youth, positive occipital sharp transients of sleep, lambda waves, and photic driving. Four examples of epileptiform patterns that are commonly seen in the posterior leads were also collected (Figure 2). These include eye closure related spike and wave complexes, occipital sharp waves, photoparoxysmal response, and posterior lateralized periodic discharges.
Conclusions: The overreading of an EEG can have long-term and serious consequences for a patient. It is important to accurately identify and distinguish normal variants from epileptiform patterns on EEG.
Funding: None
Neurophysiology