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
- Chapter 1 Introduction
- Chapter 2 Polarity and Montages
- Chapter 3 Localization
- Chapter 4 Frequency and Rhythm
- Chapter 5 Maturation
- Chapter 6 Normal Adult EEG
- Part II Interpretation
- Part III Specific Conditions
- Appendix: How to Write a Report
- Index
- References
Chapter 4 - Frequency and Rhythm
from Part I - Basics
Published online by Cambridge University Press: 27 September 2025
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
- Chapter 1 Introduction
- Chapter 2 Polarity and Montages
- Chapter 3 Localization
- Chapter 4 Frequency and Rhythm
- Chapter 5 Maturation
- Chapter 6 Normal Adult EEG
- Part II Interpretation
- Part III Specific Conditions
- Appendix: How to Write a Report
- Index
- References
Summary
This chapter discusses the concepts of frequency and rhythm including the alpha rhythm, its normal variations and abnormalities, and other common rhythms such as beta, theta, and delta rhythms. Frequency is the number of times a waveform occurs per second whereas a rhythm specifically refers to additional features such as location, morphology, reactivity, and state dependence of the pattern. Frequencies are descriptive but rhythms have diagnostic significance. Clinically relevant frequency bands are delta, theta, alpha, and beta in increasing order. The alpha rhythm is an obligate feature of normal wakefulness but has many variations. Excessive beta activity is a nonspecific finding that may be associated with sedative medications. In most people theta and delta activity (slowing) is limited to drowsiness and sleep and their presence during wakefulness may be abnormal. [130 words/750 characters]
Information
- Type
- Chapter
- Information
- How to Read an EEG , pp. 33 - 41Publisher: Cambridge University PressPrint publication year: 2025
References
Tatum, WO IV, Husain, AM, Benbadis, SR, Kaplan, PW. Normal adult EEG and patterns of uncertain significance. Journal of Clinical Neurophysiology. 2006 Jun 1;23(3):194–207.10.1097/01.wnp.0000220110.92126.a6CrossRefGoogle ScholarPubMed
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