Book contents
- How to Read an EEG
- Reviews
- How to Read an EEG
- Copyright page
- Dedication
- Contents
- Figure Contributions
- Foreword to the First Edition
- Preface
- How to Read This Book
- Part I Basics
- Part II Interpretation
- Chapter 7 Approach to EEG Reading
- Chapter 8 Describing Abnormalities
- Chapter 9 Artifacts
- Chapter 10 Normal Variants
- Chapter 11 Sporadic Abnormalities
- Chapter 12 Repetitive Abnormalities
- Chapter 13 Ictal Patterns (Electrographic Seizures)
- Chapter 14 Activation Procedures
- Part III Specific Conditions
- Appendix: How to Write a Report
- Index
- References
Chapter 10 - Normal Variants
from Part II - Interpretation
Published online by Cambridge University Press: aN Invalid Date NaN
Book contents
- How to Read an EEG
- Reviews
- How to Read an EEG
- Copyright page
- Dedication
- Contents
- Figure Contributions
- Foreword to the First Edition
- Preface
- How to Read This Book
- Part I Basics
- Part II Interpretation
- Chapter 7 Approach to EEG Reading
- Chapter 8 Describing Abnormalities
- Chapter 9 Artifacts
- Chapter 10 Normal Variants
- Chapter 11 Sporadic Abnormalities
- Chapter 12 Repetitive Abnormalities
- Chapter 13 Ictal Patterns (Electrographic Seizures)
- Chapter 14 Activation Procedures
- Part III Specific Conditions
- Appendix: How to Write a Report
- Index
- References
Summary
Normal variants are unusual appearing waveforms that are normal variations that may be confused with an abnormality. Normal variants should be recognized and distinguished from epileptogenic and ictal patterns to prevent misdiagnosis of epilepsy. Variants are identified based on their appearance, typical location, state, and age group. They may be sharp, rhythmic, or posterior predominant. Antiepileptic medications such as valproic acid or levetiracetam may blunt epileptic discharges and reduce their amplitude, making them less distinct from the surrounding background. These “blunted discharges” can sometimes be mistaken for normal variants. [94 words/587 characters]
Information
- Type
- Chapter
- Information
- How to Read an EEG , pp. 120 - 150Publisher: Cambridge University PressPrint publication year: 2025
References
Smith, D, Defalla, BA, Chadwick, DW. The misdiagnosis of epilepsy and the management of refractory epilepsy in a specialist clinic. QJM. 1999 Jan 1;92(1):15–23.CrossRefGoogle Scholar
Aminoff, MJ. Electroencephalography: general principles and clinical applications. In Electrodiagnosis in clinical neurology, 6th ed.; Aminoff, MJ, Ed. (pp. 37–84). Elsevier, New York; 2012.CrossRefGoogle Scholar
Krauss, GL, Abdallah, A, Lesser, R, Thompson, RE, Niedermeyer, E. Clinical and EEG features of patients with EEG wicket rhythms misdiagnosed with epilepsy. Neurology. 2005 Jun 14;64(11):1879–83.10.1212/01.WNL.0000163991.97456.03CrossRefGoogle ScholarPubMed
Tatum, WO IV, Husain, AM, Benbadis, SR, et al. Normal adult EEG and patterns of uncertain significance. Journal of Clinical Neurophysiology. 2006;23(3):194–207.CrossRefGoogle ScholarPubMed
Tatum, WO, DiCiaccio, B, Kipta, JA, Yelvington, KH, Stein, MA. The texting rhythm: a novel EEG waveform using smartphones. Journal of Clinical Neurophysiology. 2016 Aug 1;33(4):359–66.10.1097/WNP.0000000000000250CrossRefGoogle ScholarPubMed
Aird, RB, Gastaut, Y. Occipital and posterior electroencephalographic rhythms. Electroencephalography and Clinical Neurophysiology. 1959 Nov 1;11(4):637–56.CrossRefGoogle ScholarPubMed
Van Cott, AC. Epilepsy and EEG in the elderly. Epilepsia. 2002 Mar; 43:94–102.10.1046/j.1528-1157.43.s.3.10.xCrossRefGoogle ScholarPubMed
Libenson, MH, Caravale, B. Do antiepileptic drugs differ in suppressing interictal epileptiform activity in children? Pediatric Neurology. 2001 Mar 1;24(3):214–18.10.1016/S0887-8994(00)00271-XCrossRefGoogle ScholarPubMed
Accessibility standard: WCAG 2.2 AAA
The PDF of this book
complies with version 2.2 of the
Web Content Accessibility Guidelines
(WCAG), offering more comprehensive accessibility measures for a broad range
of users and attains the highest
(AAA)
level of WCAG compliance, optimising the user experience by meeting the most extensive
accessibility guidelines.
Content Navigation
Table of contents navigation
Allows you to navigate directly to chapters, sections, or non‐text items through a linked table of contents, reducing the need for extensive scrolling.
Allows you to navigate directly to chapters, sections, or non‐text items through a linked table of contents, reducing the need for extensive scrolling.
Index navigation
Provides an interactive index, letting you go straight to where a term or subject appears in the text without manual searching.
Provides an interactive index, letting you go straight to where a term or subject appears in the text without manual searching.
Reading Order & Textual Equivalents
Single logical reading order
You will encounter all content (including footnotes, captions, etc.) in a clear, sequential flow, making it easier to follow with assistive tools like screen readers.
You will encounter all content (including footnotes, captions, etc.) in a clear, sequential flow, making it easier to follow with assistive tools like screen readers.
Short alternative textual descriptions
You get concise descriptions (for images, charts, or media clips), ensuring you do not miss crucial information when visual or audio elements are not accessible.
You get concise descriptions (for images, charts, or media clips), ensuring you do not miss crucial information when visual or audio elements are not accessible.
Full alternative textual descriptions
You get more than just short alt text: you have comprehensive text equivalents, transcripts, captions, or audio descriptions for substantial non‐text content, which is especially helpful for complex visuals or multimedia.
You get more than just short alt text: you have comprehensive text equivalents, transcripts, captions, or audio descriptions for substantial non‐text content, which is especially helpful for complex visuals or multimedia.
Visual Accessibility
Use of colour is not sole means of conveying information
You will still understand key ideas or prompts without relying solely on colour, which is especially helpful if you have colour vision deficiencies.
You will still understand key ideas or prompts without relying solely on colour, which is especially helpful if you have colour vision deficiencies.
Use of high contrast between text and background colour
You benefit from high‐contrast text, which improves legibility if you have low vision or if you are reading in less‐than‐ideal lighting conditions.
You benefit from high‐contrast text, which improves legibility if you have low vision or if you are reading in less‐than‐ideal lighting conditions.