Electroencephalography: Textbook and Atlas

Electroencephalography (EEG) is one of the oldest neurophysiological techniques used to evaluate brain activity and is a cornerstone of technical diagnostics in neurology. The technical advancement of electroencephalography in the last few decades, however, asks for a new approach to EEG reading. This textbook and atlas provides a systematic approach to normal and abnormal EEG patterns, serving as an instructional guide for the beginner in EEG and an essential reference for the experienced EEG reader. Containing about 400 figures illustrating typical EEG patterns which are also available online in reformatted referential and bipolar montages, this book covers how electrical waves are generated into the brain, the equipment required to record electrical brain waves (including the set-up of EEG machines, electrodes, and procedures), biological and non-biological disturbances called artifacts in EEG recordings, and differentiation of normal and abnormal patterns in EEG. The reader will be introduced to a systematic analysis of EEG interpretation by defining the characteristics of the EEG patterns (polarity, localization, frequency, modulation etc.) and their clinical meaning, making this an essential text that should be on the bookshelf of every medical professional using EEG.

Table of Contents:

1 Introduction

2 Fundamentals of Electroencephalography

2.1 Biological Basis of Electroencephalography

2.1.1 Source of EEG Signal

2.1.1.1 Action Potentials

2.1.1.2 Synaptic Potentials

2.1.1.3 Spatial Arrangement of Electric Fields

2.1.2 Fundamentals of Rhythmic EEG Activity

2.2 Physical and Technical Fundaments of the EEG

2.2.1 Technical Structure

2.2.1.1 Electrodes and Skin Contact

2.2.1.2 Electrodes

2.2.1.3 Differential Amplifier

2.2.1.4 Analog-to-Digital Conversion

2.2.1.5 Video

2.2.1.6 Electrical Safety

2.2.2 Technical Characteristics of EEG Recording

2.2.2.1 EEG Filters

2.2.2.1.1 Electrotechnical Basis of Filters

2.2.2.1.2 Phase Shift due to Filters

2.2.2.1.3 Recommended Filter Settings

2.2.2.2 Editing the Digital EEG

2.2.2.2.1 Reformatting

2.2.2.2.2 Referential Montages

2.2.2.2.3 Bipolar Montages

2.2.2.2.4 Source Analysis and Mapping

2.2.2.2.5 Automatic Spike Detection/AI implementation

2.2.2.2.6 Automatic Seizure Detection

2.2.2.2.7 Long-Term EEG Monitoring

2.2.3 Localization of EEG Potentials

2.2.3.1 Polarity Convention

2.2.3.2 Systematic Approach to Localization of EEG Potentials

2.2.3.3 Advantages and Disadvantages of Bipolar and Referential Montages

2.2.3.4 Localization of Asymmetries

2.3 Artifacts

2.3.1 Nonbiological Artifacts

2.3.1.1 Electrode Artifacts (“Electrode Pop”)

2.3.1.2 Ballistic Artifacts

2.3.1.3 Open Channel

2.3.1.4 External Artifacts

2.3.2 Biological Artifacts

2.3.2.1 Bulb Movements

2.3.2.2 Muscle Artifacts

2.3.2.3 Glossokinetic Artifacts

2.3.2.4 Eye Muscle Artifacts

2.3.2.5 ECG Artifacts

3 Clinical Electroencephalography

3.1 Recording of Electroencephalograms

3.1.1 Default Settings for EEG Recording

3.1.2 Recording of Newborn EEGs

3.2 Activation Methods

3.2.1 Hyperventilation

3.2.2 Photic Stimulation

3.2.3 Sleep and Sleep Deprivation

3.2.4 Eye Closure

3.3 EEG Reading

3.3.1 Description of Abnormal EEG

3.3.1.1 Frequency

3.3.1.2 Amplitude

3.3.1.3 Localization

3.3.1.4 Shape and Temporal Behavior

3.3.1.5 Responsiveness/Reactivity

3.3.2 Reporting of EEG

3.4 EEG Classification

3.4.1 Normal Patterns

3.4.1.1 Physiological Wake EEG

3.4.1.1.1 Posterior Alpha Activity

3.4.1.1.2 Central Mu Activity

3.4.1.1.3 Frontal Beta Activity

3.4.1.1.4 Temporal Theta Activity

3.4.1.2 Physiological Sleep EEG

3.4.2 Abnormal EEG

3.4.2.1 Degree of EEG Abnormality

3.4.2.2 State of Consciousness

3.4.2.3 Slow and Suppression

3.4.2.3.1 Background Slow (BS)

3.4.2.3.2 Intermittent Slow (IS)

3.4.2.3.2.1 Intermittent Rhythmic Slow (IRS)

3.4.2.3.2.2 Temporal Slow of the Elderly

3.4.2.3.2.3 Hypnagogic/Hypnopompic Theta–Delta Bursts

3.4.2.3.2.4 Occipital Slow of Youth

3.4.2.3.2.5 Eye Closure Activity

3.4.2.3.2.6 Rhythmical Temporal Theta Bursts of Drowsiness

3.4.2.3.2.7 Rhythmical Midline Theta

3.4.2.3.3 Continuous Slow (CS)

3.4.2.3.4 Background Attenuation (BA)

3.4.2.3.5 Background Suppression (BSU)

3.4.2.3.6 Electrocerebral Silence (ECS)

3.4.2.4 Epileptiform Discharges (ED)

3.4.2.4.1 Spikes (SP)

3.4.2.4.2 Polyspikes (PSP) and Paroxysmal Fast (PF)

3.4.2.4.3 Benign Focal Epileptiform Discharges (BFED)

3.4.2.4.4 Spike–Waves (SW)

3.4.2.4.5 Polyspike–Waves (PSW)

3.4.2.4.6 3 Hz Spike–Waves (3SW)

3.4.2.4.7 Slow Spike–Waves (SSW)

3.4.2.4.8 Hypsarrhythmia (HYP)

3.4.2.4.9 Photoparoxysmal Response (PR)

3.4.2.4.10 Seizure Patterns (SEP)

3.4.2.4.10.1 Semiological Seizure Classification

3.4.2.4.11 Status Patterns (STP)

3.4.2.4.12 Differential Diagnoses of Interictal Epileptiform Discharges

3.4.2.4.12.1 Wicket Spikes

3.4.2.4.12.2 Asymmetry, Increased Background

3.4.2.4.12.3 Benign Epileptiform Transients of Sleep (BETS)

3.4.2.4.12.4 14 and 6 Hz Positive Spikes

3.4.2.4.12.5 6 Hz “Phantom” Spike and Wave

3.4.2.5 Periodic Patterns (PP)

3.4.2.5.1 Periodic Discharges

3.4.2.5.2 Periodic Epileptiform Discharges (PED)

3.4.2.5.3 Triphasic Waves (TW)

3.4.2.5.4 Burst Suppression (BUS)

3.4.2.5.5 Burst Attenuation (BUA)

3.4.2.6 Differentiation of Nonconvulsive Status Epilepticus and Encephalopathies

3.4.2.7 Special Patterns

3.4.2.7.1 Excessive Beta (EB)

3.4.2.7.2 Asymmetry (ASY)

3.4.2.7.3 Sleep-Onset REM (SOREM)

3.4.2.8 Special Patterns in Stupor and Comas

3.4.2.8.1 Alpha Coma (AK) and Alpha Stupor (AS)

3.4.2.8.2 Spindle Coma (SK) and Spindle Stupor (SS)

3.4.2.8.3 Beta Coma (BK) and Beta Stupor (BES)

3.4.2.8.4 Theta Coma (TK) and Theta Stupor (TS)

3.4.2.8.5 Delta Coma (DK) and Delta Stupor (DS)

Appendix 1. EEG Guidelines of the American Clinical Neurophysiological Society

Appendix 2. Semiological Seizure Classification

References

Index