Related Experiment Video

Updated: May 21, 2026

Long-term Continuous EEG Monitoring in Small Rodent Models of Human Disease Using the Epoch Wireless Transmitter System

Long-term Continuous EEG Monitoring in Small Rodent Models of Human Disease Using the Epoch Wireless Transmitter System

Published on: July 21, 2015

Impact of prolonged periodic epileptiform discharges on coma prognosis

Charlene Ong¹, Emily Gilmore, Jan Claassen

¹Department of Neurology, University of Washington in St. Louis, 660 S. Euclid Avenue, St. Louis, MO 63110, USA. cjo9333@bjc.org

Neurocritical Care

|June 16, 2012

Abstract

Background:

Periodic epileptiform discharges (PEDs) are a frequent finding in comatose patients undergoing continuous EEG (cEEG) monitoring, but their clinical significance is unclear. PET and SPECT studies indicate that PEDs can be associated with focal hypermetabolism and hyperemia, suggesting that in some cases this pattern may be ictal and potentially harmful. We hypothesized that frequent PED activity in comatose patients is associated with reduced likelihood of recovery of consciousness.

Methods:

We identified all comatose patients treated in the Columbia neuro-ICU between June 2008 and August 2009 who underwent ten or more consecutive days of video cEEG monitoring (N = 67), and classified them into three groups: those with (1) prolonged PEDs (five or more consecutive days), (2) intermittent PEDs (at least one but fewer than five consecutive days), and (3) no PEDs. Outcome at discharge was assessed by the Glasgow Outcome Scale and classified as dead (GOS 1), vegetative (GOS 2), and command-following (GOS 3-5).

Results:

Mean age was 56 years, mean admission Glasgow Coma Scale score was seven, and the median duration of cEEG monitoring was 18 (range 10-111) days. The most common diagnoses were hypoxic-ischemic encephalopathy (18%), subarachnoid hemorrhage (16%), epilepsy (15%), encephalitis (15%), metabolic encephalopathy (13%), and intracerebral hemorrhage (12%). 37% of patients (N = 25) had prolonged PEDs, 31% (N = 21) had intermittent PEDs, and 31% (N = 21) had no PEDs. Prolonged PEDs were associated with the presence of SIRPIDS (P = 0.009), electrographic seizures (P = 0.019), and number of AEDs administered (P < 0.0001). However, the presence of intermittent or prolonged PED activity had no impact on mortality (31% overall) or recovery of consciousness (command-following) at the time of discharge (36% overall).

Conclusion:

Persistent spontaneous PED activity in comatose patients is associated with SIRPIDs and electrographic seizures, but has no impact on the likelihood of survival or recovery of consciousness.

More Related Videos

Use of a Wireless Video-EEG System to Monitor Epileptiform Discharges Following Lateral Fluid-Percussion Induced Traumatic Brain Injury

Use of a Wireless Video-EEG System to Monitor Epileptiform Discharges Following Lateral Fluid-Percussion Induced Traumatic Brain Injury

Published on: June 21, 2019

Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus

Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus

Published on: April 5, 2011

Related Concept Videos

Epilepsy and Seizures: Overview

Epilepsy and Seizures: Overview

Epilepsy is a chronic neurological disease marked by recurrent, unpredictable seizures. These seizures are caused by abnormal electrical discharges in the brain, leading to behavior, sensation, or consciousness alterations. They can also cause transient impairment of awareness, interfering with daily activities.
Various factors can trigger epilepsy, including genetic factors, brain damage, metabolic causes, and unknown etiology. Diagnosis of epilepsy involves electroencephalography (EEG), which...

Seizures l: Introduction

Seizures l: Introduction

Understanding seizures and epilepsy relies on key definitions that help in recognizing, classifying, and managing these disorders. These definitions provide a framework for recognizing, classifying, and managing seizure disorders.DefinitionsA seizure is a sudden, abnormal burst of electrical activity in the brain that can cause changes in awareness, movement, sensation, or behavior, depending on the area involved. Epilepsy is a chronic condition characterized by recurrent, unprovoked seizures,...

Seizures: Classification

Seizures: Classification

Epilepsy is primarily characterized by unpredictable seizures, either provoked by an identifiable factor, such as injury or illness, or unprovoked, occurring spontaneously without apparent cause.
Seizures are typically classified into two main categories: focal and generalized seizures.
Focal Seizures
Focal seizures originate from specific regions of the brain. These seizures are further sub-classified into two types:

Electroconvulsive Therapy

Electroconvulsive Therapy

Electroconvulsive therapy (ECT), or shock therapy, remains a critical biomedical intervention for severe, treatment-resistant depression. While its origins can be traced back to Hippocrates' observations that malaria-induced convulsions alleviated mental illness, modern ECT has evolved significantly from its earlier, more primitive applications. First introduced in 1938 by Ugo Cerletti and his colleagues, ECT involves inducing controlled seizures using electrical currents. In its early years,...

Epilepsy ll: Types

Epilepsy ll: Types

Recurrent seizures, stemming from abnormal electrical activity in the brain, are the defining characteristic of epilepsy, a chronic neurological condition. Because seizure features vary greatly, epilepsy is classified using two systems: by seizure type and by epilepsy syndromes. These classifications enable clinicians to describe seizure patterns and select suitable treatment strategies.I. Classification by Seizure Type1. Focal EpilepsyFocal epilepsy begins in one hemisphere of the brain.

Seizures ll: Types

Seizures ll: Types

Seizures are sudden bursts of abnormal electrical discharge in the brain that interfere with normal function. They are commonly divided into three groups: focal seizures, generalized seizures, and other types that do not fit neatly into either category.Focal SeizuresFocal seizures begin in a single brain region. When awareness is preserved, they are called focal aware seizures and may cause sensations such as tingling, unusual smells, or flashing lights. When awareness is impaired, they are...

Articles linked to this work by shared authors, journal, and citation graph.

Acute and Long-Term EEG and seizure characteristics in new onset refractory status epilepticus (NORSE).

Epilepsia·2026

Accuracy of the rapid-response electroencephalography's Automated Seizure Burden Estimator: A follow-up validation study of version 8 (AccuRASE II).

Epilepsia·2026

Multi-center pressure reactivity index temporal trajectories for predicting outcome in comatose subarachnoid hemorrhage patients.

Neurosurgical review·2026

Acute Brain Injury in New-Onset Refractory Status Epilepticus and Etiology-Defined Status Epilepticus.

JAMA neurology·2026

Association of plasma transfusion timing with mortality among patients with traumatic intracranial hemorrhage across US adult civilian trauma centers.

The journal of trauma and acute care surgery·2026

Consensus statement from the 2025 Delphi panel on cerebral microdialysis in critical care.

Critical care (London, England)·2026

See all related articles