Neurological Differential Diagnosis: A Prioritized Approach

557 Pages·2005·13.37 MB·English

by  Roongroj Bhidayasiri

Neurological
Differential
Diagnosis
Neurological
Differential
Diagnosis
A Prioritized Approach
Roongroj Bhidayasiri,
MD, MRCP(UK), MRCPI
Department of Neurology
David Geffen School of Medicine at UCLA and
Parkinson Disease Research, Education and Clinical Center (PADRECC) of West Los Angeles
Veterans Affairs Medical Center
Los Angeles, CA
Michael F. Waters,
MD, PhD
Department of Neurology
David Geffen School of Medicine at UCLA
Los Angeles, CA
Christopher C. Giza,
MD
UCLA Brain Injury Research Center
Divisions of Neurosurgery and Pediatric Neurology
David Geffen School of Medicine at UCLA
Los Angeles, CA
© 2005 Roongroj Bhidayasiri, Michael F. Waters and Christopher C. Giza
Published by Blackwell Publishing Ltd
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First published 2005
Library of Congress Cataloging-in-Publication Data
Bhidayasiri, Roongroj.
Neurological differential diagnosis : a prioritized approach / by Roongroj Bhidayasiri, Michael F.
Waters, Christopher C. Giza.
p. ; cm.
Includes index.
ISBN-13: 978-1-4051-2039-5 (alk. paper)
ISBN-10: 1-4051-2039-8 (alk. paper)
1. Nervous system--Diseases--Diagnosis--Handbooks, manuals, etc. 2. Diagnosis, Differential--Hand-
books, manuals, etc.
[DNLM: 1. Nervous System Diseases--diagnosis--Handbooks. 2. Diagnostic Techniques, Neurological-
-Handbooks. ] I. Waters, Michael F. II. Giza, Christopher C., 1965- III. Title.
RC348.B485 2005
616.8’0475--dc22
2005001189
ISBN 13: 978-1-4051-2039-5
ISBN 10: 1-4051-2039-8
A catalogue record for this title is available from the British Library
Set in 10/13 pt Minion by Sparks, Oxford – www.sparks.co.uk
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Although every effort has been made to ensure that drug doses and other information are presented
accurately in this publication, the ultimate responsibility rests with the treating physician. Neither the
publishers nor the authors can be held responsible for any consequences arising from the use of infor-
mation contained herein. Any product mentioned in this publication should be used in accordance
with the prescribing information prepared by the manufacturers.
Dedication
To my loving grandmother, Pranom Chivakiat, my parents, Mitr & Nisaratana
Bhidayasiri, all my teachers of neurology, and lastly all my patients who have taught
me much about neurology.
RB
I would like to dedicate this work to my family, friends, and colleagues, especially
Alejandra, for helping to keep my tank full.
MFW
To my wonderful wife, Rosanne, who gave me our son and greatest joy, Vincent, and
my parents, Chester & Yueh-hua who started me on my journey.
CCG
Contents
Foreword, ix
Preface, xiii
Acknowledgements, xiv
How to Use this Book, xv
1 Neuroanatomy and Neuropathology, 1
2 Clinical Syndromes, 62
3 Vascular Neurology, 107
4 Paroxysmal Disorders, 149
5 Neuropsychiatry and Dementia, 173
6 Movement Disorders, 202
7 Infectious, Infl ammatory, and Demyelinating Disorders, 239
8 Peripheral Neurology, 268
9 Neuro-ophthalmology and Neuro-otology, 294
10 Neuro-oncology, 323
11 Pediatric Neurology, 345
12 Neurogenetics, 382
13 Neuroradiology, 403
14 Spinal Cord Disorders, 443
15 Diagnostic Tests, 462
Appendix A: Clinical Pearls, 509
Appendix B: Abbreviations, 523
Index, 525
vii
Foreword
Every time a physician encounters a patient for the purpose of diagnosis and
treatment, a complicated process occurs. It is obvious that this process must be
successful if a physician is to choose an optimal therapy in a timely fashion. Such
reasoning requires the physician to identify important facts in the history from the
patient, family members, and, in some cases, witnesses. The appearance of the pa-
tient and the physical examination confi rm suspicions identifi ed from the history.
The importance of signs and symptoms must be ranked in terms of their relative
importance to the diagnosis at hand, eliminating artifactual information as well as
true fi ndings that are irrelevant to the current diagnosis, such as those related to
prior diagnoses. The resulting set of facts must then be applied to a large store of
possible disorders weighted by the patient’s demographic features such as gender,
age, ethnicity, habits, and geographical factors as well as the time-intensity relation-
ship (e.g. acute, subacute, chronic) and temporal pattern (e.g. progressive, episodic,
relapsing) of the onset of the medical problem at hand.
The nervous system provides a unique set of deductive reasoning opportunities
in that its architecture is not homogeneous but compartmentalized by functional
systems composed of groups of cell bodies and the fi ber tracts that connect them.
This information can then be applied to possible diagnoses constrained by ana-
tomical localization, temporal features, and demographics. What emerges is a short,
prioritized list by likelihood, and, most importantly, concern for possibilities that
could be life threatening or produce irreparable damage to the nervous system. This
working diagnosis is then confi rmed, fi rst during the physical examination itself,
and later by laboratory methods including electrophysiological tests, imaging, and
analysis of body fl uids or biopsy material. Once confi rmed, treatment may begin.
Thus, a large body of information is sifted down to the salient facts and con-
verging in overlapping indicators that allow the selection of this short differential
diagnostic list. In many ways, this is an exercise in probability. In fact, numerous
attempts have been made to reduce the diagnostic decision-making process to a
mathematical one. Computers are especially well suited to help in collecting and
processing clinical information. They can be used to retain large lists with the ca-
pability of convergence on the most likely answer, with special attention to those
diagnoses that may be life threatening. The applications of symbolic logic, prob-
ix
x Foreword
ability theory, value theory, and Boolean algebra have all been employed in these au-
tomated strategies. Such approaches have taught us what we see and know from the
clinic on an everyday basis. Medical diagnostics should emphasize the fundamental
importance of considering combinations of symptoms or symptom complexes.
This is important because all too often an evaluation is made of a sign or symptom
by itself, without respect to the other features of the disorder, often leading to errors.
The consideration of a combination of signs and symptoms that a patient does and
does not have, in relation to possible combinations of disease, is a most effective and
effi cient approach to the diagnostic process.
This text is a marvelous example of providing the practical and probabilistic
approach to patients with disorders of the nervous system. It emphasizes prob-
ability because a neurological diagnosis can rarely be made with absolute certainty
at the bedside, but rather a short list of the ‘most likely’ diagnoses is made and then
one is later confi rmed. At the same time, the authors have made the important
contribution of also identifying those potential diagnoses that would acutely be
life threatening or result in irreparable damage to the brain, spinal cord, or peri-
pheral nerves. The importance of this strategy is self-evident. By clustering their
approach in accordance with the usual categories of neurological disorders, the
process of identifying a complex of patient symptoms, signs, demographic factors,
and temporal relationships leading to the appropriate diagnosis is simplifi ed for
the reader.
The authors have done a superb job in producing a text that is effi cient, easy to
use, practical, and accurate. Their motivation comes from practical experience. The
clinician, particularly the clinician in training, needs to be able to fi nd and quickly
assess information about the patient with whom they are concerned at that mo-
ment. It is their job to sift through the facts and artifacts, as noted above, and bring
the salient information to be merged with the compendium of lists and diseases
provided in this text.
Great diagnosticians, from experience and through their ability to generate an
instant rapport with the patient, arrive at accurate diagnoses in a remarkably ef-
fi cient fashion. Great diagnosticians also have an excellent memory for the facts of
their fi eld. Good memory alone and the ability to effi ciently prioritize data provided
by the patient are not enough, however. It is the ability to rapidly converge those data
sets to a short list or a fi nal diagnosis that makes a good physician a great diagnosti-
cian. This text provides a vehicle to help the reader think in that fashion and move
toward that role model. The authors have done a masterful job in facilitating the
process. I am certain they can be persuaded to apply these strategies to future projects
and to expand this approach within the fi elds of neurology and neurosurgery.
A fi nal comment: diagnoses, diseases, signs, and symptoms, along with their
probabilities, life threatening potentials, and other quantifi able variables are all part
of the practice of medicine. These issues are the factors that allow us to determine
what is wrong with a patient and provide treatments for their benefi t. The patient
Foreword xi
with an illness is also a human being in trouble who seeks the help of another person
with special knowledge and training. That distinction and the compassion required
to help both the person and the patient is as important as any drug or procedure that
we as physicians can provide.
John C. Mazziotta, MD, PhD
Los Angeles, California
March 30, 2004
Preface
This book has its roots in our perceived need for a concise text to assist the practi-
tioner in prioritizing likely diagnoses when encountering a patient complaining of
neurological problems or defi cits. Though many references exist on neurological
disease and differential diagnoses, few offer easily referable likely diagnoses based
on common complaints and presentation. When one approaches differential di-
agnosis in neurology, there is frequently a feeling of overwhelming information. It
is often one’s fi rst appreciation of the complexities of neurological disease and the
elegance of the neurological system when realizing that seemingly ‘anything can
cause anything’. When constructing a neurological differential diagnosis, it is often
inevitable that a page-long laundry list is quickly compiled. And, although it is true
that one cannot make a diagnosis that one doesn’t think of, it is also true that the
overwhelming majority of diagnoses can be made by considering the top fi ve or so
possibilities. Common things are commonly seen. Moreover, it is also true that one
practices today in an environment of limited time and limited resources. Therefore,
shouldn’t one be considering the most likely diagnoses fi rst, working up those pos-
sibilities, and moving forward if that approach fails to yield the answer? The caveat,
of course, is that dangerous or disabling diagnoses must be considered early on to
limit death and disability. These principles have directed the construction of this
book. While many of the differentials are somewhat lengthy, they are arranged to
direct the reader to consider the most likely and most dangerous possibilities fi rst,
saving the lesser possibilities for those instances when a comprehensive differential
is required for an accurate diagnosis. This book is not, nor is it intended to be, an
exhaustive reference. It is, however, an attempt to rationally focus one’s attention in
a ‘high-yield’ manner. In writing this text, we are seeking to strike a balance between
being comprehensive and being practical. It is our hope that you will fi nd this book
a valuable resource when confronted with the task of formulating a neurological
differential diagnosis. Collectively, we all wish we had had it during our training,
particularly on those late nights in the emergency department.
Roongroj Bhidayasiri, Michael F. Waters, Christopher C. Giza
xiii