Table Of ContentSeizures in Critical Care
C C N
U R R E N T L I N I C A L E U RO LO G Y
Daniel Tarsy, , S E
MD ERIES DITOR
Seizures in Critical Care: A Guide to Diagnosis and Therapeutics,edited by
Panayiotis N. Varelas, 2004
Neurological and Psychiatric Disorders:From Bench to Bedside, edited by
Frank I. Tarazi and John A. Schetz, 2005
Movement Disorders Emergencies: Diagnosis and Treatment,edited by Steven
J. Frucht and Stanley Fahn, 2005
Inflammatory Disorders of the Nervous System: Pathogenesis, Immunology,
and Clinical Management,edited by Alireza Minagar and J. Steven Alexander,
2005
Multiple Sclerosis: Etiology, Diagnosis, and New Treatment Strategies, edited
byMichael J. Olek, 2005
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and Ivan Bodis-Wollner, 2005
Vascular Dementia: Cerebrovascular Mechanisms and Clinical Management,
edited by Robert H. Paul, Ronald Cohen, Brian R. Ott, Stephen Salloway,2005
Atypical Parkinsonian Disorders, edited by Irene Litvan, 2005
Handbook of Neurocritical Care, edited by Anish Bhardwaj, Marek A. Mirski,
and John A. Ulatowski, 2004
Handbook of Stroke Prevention in Clinical Practice, edited by Karen L. Furie
and Peter J. Kelly, 2004
Clinical Handbook of Insomnia, edited by Hrayr P. Attarian, 2004
Critical Care Neurology and Neurosurgery, edited by Jose I. Suarez, 2004
Alzheimer’s Disease:A Physician’s Guide to Practical Management, edited
byRalph W. Richter and Brigitte Zoeller Richter, 2004
Field of Vision: A Manual and Atlas of Perimetry, edited by Jason J. S. Barton and
Michael Benatar, 2003
Surgical Treatment of Parkinson’s Disease and Other Movement Disorders, edited
byDaniel Tarsy, Jerrold L. Vitek, and Andres M. Lozano, 2003
Myasthenia Gravis and Related Disorders, edited by Henry J. Kaminski, 2003
Seizures:Medical Causes and Management, edited by Norman Delanty, 2002
Clinical Evaluation and Management of Spasticity, edited by David A. Gelber
and Douglas R. Jeffery, 2002
Early Diagnosis of Alzheimer's Disease, edited by Leonard F. M. Scinto and Kirk
R. Daffner, 2000
Sexual and Reproductive Neurorehabilitation, edited by Mindy Aisen, 1997
Seizures in Critical Care
A Guide to Diagnosis
and Therapeutics
Edited by
Panayiotis N. Varelas, MD, PhD
Departments of Neurology and Neurosurgery
Medical College of Wisconsin, Milwaukee, WI
Foreword by
Susan S. Spencer,
MD
Department of Neurology and Neurosurgery
Yale School of Medicine, Yale University, New Haven, CT
© 2005 Humana Press Inc.
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Library of Congress Cataloging-in-Publication Data
Seizures in critical care : a guide to diagnosis and therapeutics / edited by Panayiotis N. Varelas.
p. ; cm. -- (Current clinical neurology)
Includes bibliographical references and index.
ISBN 1-58829-342-4 (alk. paper)
1. Convulsions. 2. Critical care medicine.
[DNLM: 1. Seizures--diagnosis. 2. Seizures--therapy. 3. Critical Care--methods.
WL 340 S4617 2004] I. Varelas, Panayiotis N. II. Series.
RC394.C77S445 2004
616.8'45--dc22
2004004126
Series Editor’s Introduction
The evaluation and treatment of seizures in the very demanding environment of
the critical care setting has not received sufficient attention in a focused monograph
on the subject. Seizures in Critical Care: A Guide to Diagnosis and Therapeutics
fills that need extremely well and serves as an indispensable companion to previous
works in the Current Clinical Neurology Series, Seizures: Medical Causes and
Management by Delanty, Critical Care Neurology and Neurosurgery by Suarez,
andHandbook of Neurocritical Careby Bhardwaj, Mirski, and Ulatowski. The two
volumes on critical care contain excellent chapters concerning management of sta-
tus epilepticus. The current volume fills out the field by adding invaluable informa-
tion concerning the wide range of specific critical care situations in which seizures
of all types occur and how they are best managed in those contexts.
Seizures are a very concerning and frightening event. As repeatedly pointed out
in this volume, the incidence of seizures in various underlying medical and neuro-
logical disorders is astonishingly high. When they occur in the intensive care unit
setting, they are nearly always symptomatic of serious underlying medical derange-
ments and are often perceived, correctly or incorrectly, as heralding a significant
downturn in the patient’s clinical course. In the particular case of hypoxic–ischemic
brain injury, they have been thought to be predictive of adverse outcomes that, as
indicated by Drs. Koenig and Geocadin, may not necessarily be the case.
Management of seizures begins with their prompt recognition and differentia-
tion from other types of involuntary movements and changes in mental status which
frequently occur in seriously ill patients. In particular, the surprising frequency
with which nonconvulsive status epilepticus presents in the intensive care unit and
how often it is missed underscores the need for careful clinical evaluation and the
timely use of bedside electroencephalography in making this diagnosis. Because
“seizures beget seizures” the urgency of prompt diagnosis and early effective treat-
ment is paramount. Treatment of seizures begins with the identification and man-
agement of the usual suspects, such as metabolic, electrolyte, infectious, vascular,
and pharmacologic contributors. The use of anticonvulsants requires particular skill
in patients with organ failure and in patients being treated with numerous other
drugs capable of interacting with anticonvulsants. All of these issues are addressed
in great depth and with considerable sophistication by the impressive array of con-
tributors to this volume.
Daniel Tarsy, MD
Beth Israel Deaconess Medical Center
Harvard Medical School, Boston, MA
v
Foreword
Seizures and Critical Care: A Guide to Diagnosis and Therapeutics is a gem
among monographs, as well as a tribute to the creativity, insight, and hard work of
its editor. The idea itself is totally new. Now that it is complete and before me in
finished form, I find myself wondering why this was never done before. It was a
challenge to define all the issues, and then find a set of authors to soundly and
comprehensively address the identified issues. The topic has been circumscribed
for the first time.
In its final form, Seizures and Critical Care: A Guide to Diagnosis and Thera-
peuticsis practically a text of epilepsy, even in a way a text of medicine. The num-
ber of situations in which seizures are precipitated, particularly in an intensive care
unit (ICU) setting, recapitulates the systems of the body and the ways in which their
altered functions affect the nervous system (and other systems). The brain responds
to extreme malfunction of any system in a variety of ways, one of which is almost
always the possibility of seizure. Understanding the manner in which this might
occur, and the many approaches to diagnosis and treatment, is critical to progress in
intensive care. This is all the more important because of the fragile situation often
faced by the clinician caring for patients in an ICU setting, in which multiple other
systems and derangements, as well as treatments and drug interactions, must be
considered in the appropriate selection of therapy, monitoring, and followup. All of
those aspects are recognized and addressed.
Just as the brain may respond to extreme malfunction of any and all systems
with seizures, the clinician responds to seizures with a variety of approaches, some
of which are inherently incorrect for some situations, even while preferred in oth-
ers. Seizures in the intensive care setting may precipitate additional systemic or
central nervous system compromise requiring compatible and thoughtful handling.
If initial treatment fails, the steps to be followed may be novel, and require consid-
eration of the myriad of other health risks in this setting. We need guidelines for
diagnosis, selection of treatment, implementation of treatment, and assessment of
outcome. Furthermore, where no answer exists, we need a balanced consideration
of the areas of controversy.
Seizures and Critical Care: A Guide to Diagnosis and Therapeutics therefore
fills a need we may not have even realized exists. It updates multiple antiquated
misconceptions by discussing old controversies and finalizing some reasonable
approaches and conclusions. It defines other controversies and objectively consid-
ers the data available, and the aspects that remain unknown.
The authoritative reviews with many references are welcome additions to our
literature. The uniform format incorporating epidemiology and incidence, patho-
physiology, diagnostic and treatment interventions, and outcome and its measure-
vii
viii Foreword
ment make it easy to read and approach each chapter. The reviews are comprehen-
sive, accurate, well written, and unique in this field. The book will be of use to
almost anyone who manages patients in a neurological or general medical or surgi-
cal intensive care setting.
I am proud to say that I had some part in the education and development of Dr.
Varelas and was able to observe the formation of the idea, the process, and the
completion of this most remarkable and useful work. It will certainly bring critical
care neurology to a higher level, while identifying potential areas of fruitful and
important research for the future.
Susan S. Spencer, MD
Department of Neurology and Neurosurgery
Yale School of Medicine, Yale University,
New Haven, CT
Preface
Seizures are devastating events in a person’s life. Their very presence suggests
that something is wrong with the brain. In some regions, seizures are believed to be
caused by spirits; and in others, they are a “sacred illness,” either a curse or a reason
for awe. As a result of my training at Yale University, which has one of the best
epilepsy centers in North America, and because I am married to an epileptologist, I
have had extensive exposure to the study of seizures. Consequently, I could not
escape their spell.
I became intrigued by the diversity of their presentation and fascinated by the
possibility that various simple or complex behaviors, within the normal or abnor-
mal range, could be explained by such an “obsolete” machine as the electroen-
cephalograph (EEG). Later, after my training as a neurointensivist, my interest grew
further as I was trying to find treatable causes in somnolent or comatose patients
with various brain injuries in the intensive care unit (ICU). The simplistic and
mechanistic suspicion that the patient’s clinical status resulted from an electrical
discharge of the brain led, I am sure, to several unnecessary requests for EEGs and
trials of antiepileptics. Fortunately, I also had some unexpected successes.
I started looking at the issue of seizures more closely and had revealing discus-
sions with my peers, especially those who were not neurointensivists. To my
surprise, two facts emerged: first, many in the ICU community did not know what
to seek, what to expect, and how and when to treat for seizure; and second, while
reviewing the literature, I found little information. Most of the articles were report-
ing small, uncontrolled series or personal experiences. Few studies were conducted
in the complex environment of an ICU. Very often, as with my personal experi-
ence, doubts regarding the epileptic nature of the phenomenon lingered. EEG, the
gold-standard test, was difficult to interpret or inconsistently ordered. In many
cases, seizures could be explained by more than one mechanism. In other cases, the
response could be attributed not so much to the administration of the usual
antiepileptics, but to the correction of more systemic derangements. Interactions
between ICU medications and antiepileptics were frequent and puzzling to the
treating physicians. Several antiepileptics either were not available for parenteral
administration or were contraindicated because of specific organ failure. Finally,
the newer antiepileptics were not well known and were seldom used in the ICU.
It did not take me long to decide to edit a book regarding seizures in the ICU.
Seizures in Critical Care: A Guide to Diagnosis and Therapeuticsis a collabora-
tive effort. Experts in both the ICU and epilepsy fields from North America and
Europe contributed chapters to this volume. I have tried to confine the content to
the most common and interesting topics in the ICU. Norman Delanty’s book,
Seizures: Medical Causes and Management, served as the starting point in many
ix
x Preface
cases; however, the scope of this book is different. This book is much more
balanced toward central nervous system insults, which can occur in the ICU.
I encouraged authors to reference personal experiences and requested that they
provide many authentic ICU cases with EEGs and neuroimages. Where data were
lacking or information was contradictory—a very common situation indeed—the
authors were advised to provide raw data and expert advice.
Our hope is that Seizures in Critical Care: A Guide to Diagnosis and Therapeutics
can serve as a useful aid in the everyday ICU and in neurological practice for
intensivists, neurologists, neurosurgeons, and any other healthcare professional or
student in this expanding field. Most importantly in my mind, but less directly, it
should constitute a testimony to the paucity of data in the field and become a
starting point for well-organized research in the future.
I dedicate this effort to my parents, my grandfather (the shining star of my life),
and all my teachers, who taught me the “ζειν” (living) and “ευζειν” (living well)
of the ancients. I am also very grateful to all my coauthors, who did an excellent
job, and especially to my wife, Marianna, for her indirect contribution and support.
Panayiotis N. Varelas, MD,PhD
