Value of a Revised EEG Coma Scale for Prognosis after Cerebral Anoxia and Diffuse Head Injury

Abstract

The prognostic validity for survival of a recently devised EEG grading scale was tested in anoxic and post-traumatic coma. This scale divides EEG in coma into five major grades and ten subdivisions with emphasis on the presence of dominant activities, their amplitude, persistence, distribution and reactivity. In this scale, patterns previously not allocated, such as "spindle pattern coma," "alpha pattern coma," and "theta pattern coma" are also included. The prognostic power of the revised scale was tested retrospectively without knowledge of clinical data in a group of patients with cerebral anoxia after cardiac arrest lasting more than seven minutes and in a group of diffuse head injuries. The validity of the scale was found to be higher than those used in previously published studies, reaching 98.4% prognostic accuracy in anoxic encephalopathies and was very high in head injuries.

Practice Parameter: Prediction of outcome in comatose survivors after cardiopulmonary resuscitation (an evidence-based review) [RETIRED]

“…This represents a condensation of the categories contained in several proposed classification systems. 24,61,62 Published EEG series include one class II study 23 and four class III studies 19,[24][25][26] (appendix E-2). Most studies report intervals from CPR to EEG recording of Ͻ3 days, but there is considerable variation.…”

Post–Cardiac Arrest Syndrome

“…Quantitative EEG (QEEG) analysis will enable nonneurologists to use this technology at the bedside. 301,302,304 Given the capability of the EEG to monitor brain activity continuously, future research can focus on developing better methods to prognosticate early, track the brain's real-time response to therapies, help understand the impact of neurological injury caused by seizures, and develop novel treatment strategies. 209 …”

The Prognostication of Cerebral Hypoxia after Out-of-Hospital Cardiac Arrest in Adults

“…A further prognostic system of classification for visual ly rated EEG features in diffuse anoxic and traumatic encephalopathies was developed by Synek [56][57][58]. This system follows the general basis of the older systems with five basic grades, but additionally the reactivity of rhythms to external stimuli is concerned and unusual pat terns such as triphasic waves [59,60], bilateral periodic lateralizcd epileptiform discharges (PLEDS) and specific frequency rhythms e.g.…”