Learn Essentials of Adult Electroencephalography (EEG)

Module 3 of EEG interpretation is dedicated to understanding 'Abnormal EEG' patterns, which are critical for diagnosing various neurological and psychiatric conditions. This module is structured as follows:

Introduction to Abnormal EEG

• Epileptiform Activity Terminology: Defines the types of epileptic activities seen on an EEG.
• Normal vs. Abnormal EEG: Differentiates between normal and abnormal EEG patterns.
• Principles of Polarity: Explains the concepts of positive and negative deflections in EEG readings.

Source Localization in EEG

• Phase Reversal: Understands how phase reversal occurs at the interface between two tissues with different electrical properties.
• End of Chain Phenomenon: Describes the phenomenon where EEG activity from a distant source appears as if it originates at the end of a chain of tissue conductors.
• Referential EEG: Explains how referential recording can influence the interpretation of EEG signals.

Focal Epileptiform Activity

• Description of Patterns: Details the characteristic EEG patterns associated with focal epilepsy.
• Clinical Significance: Discusses the implications of these patterns in the context of clinical practice.
• Silverman’s Electrodes: Explains the historical method of electrode placement used in localizing focal seizure activity.
• Temporal Lobe Epilepsy: Describes typical EEG findings in temporal lobe epilepsy.
• Frontal Lobe Epilepsy: Details frontal lobe epileptic patterns on the EEG.
• Parietal and Occipital Lobe Epilepsies: Explains less common types of focal seizures and their corresponding EEG patterns.

Generalized Epileptiform Activity

• Description of Patterns: Outlines the typical EEG patterns associated with generalized epilepsy.
• Idiopathic Generalized Epilepsy: Describes the specific EEG patterns seen in this condition.
• Clinical Significance: Discusses the clinical importance of identifying these patterns.
• Childhood Absence Epilepsy: Explains the EEG features characteristic of this condition.
• Juvenile Myoclonic Epilepsy: Describes the EEG findings in juvenile myoclonic epilepsy.
• Epilepsy with GTCS Only: Details the generalized patterns associated with absence seizures and other generalized tonic-clonic seizures (GTCS).

Abnormal Slow Waves & Amplitudes

• Normal Generalized Slow Waves: Defines normal slow wave activity across all age groups.
• Localized Periodic Discharge (PDA): Describes PDA and its significance in localizing epileptogenic foci.
• Triangular Regularly Recurring Discharges (TIRDA): Explains the characteristics of TIRDA and its association with seizures.
• Generalized Asynchronous Slow Waves: Describes asynchronous slow wave patterns that are not necessarily epileptiform.
• Focal Intermittent Rhythmic Delta Activity (FIRDA): Explains FIRDA and its association with encephalopathy.
• Amplitude Asymmetries: Discusses the significance of amplitude asymmetries in EEG interpretation.
• Breach Rhythm: Describes this pattern, which can be seen in various conditions including encephalopathy and during sleep.

Abnormal EEG Patterns

• Periodic Sharp Wave Complexes (PSWC): Explains the characteristics of PSWC and their association with non-convulsive status epilepticus.
• Periodic Generalized Complexes (PGCC): Describes these complexes, which can be seen in various neurological conditions.
• Triphasic Waves: Details this pattern often seen in hepatic encephalopathy and other metabolic disturbances.
• Burst Suppression Pattern: Explains the significance of this pattern, particularly during anesthesia or in coma.
• Epileptiform EEG Discharges in Adults: Describes focal or generalized epileptiform discharges and their clinical implications.

Case Studies

Module 4 provides a collection of case studies that illustrate the application of EEG interpretation principles in real-world scenarios. These case studies are designed to reinforce learning by demonstrating how abnormal EEG patterns correlate with specific neurological and psychiatric conditions, and how these findings guide clinical decision-making and treatment planning.

Understanding these concepts is essential for healthcare professionals who interpret EEGs, as they can provide critical diagnostic information that is crucial for patient management and care.