Sciatica and Chronic Pain: Past, Present and Future

140 Pages·2019·2.246 MB·English

by  Robert W. Baloh

Sciatica and Chronic
Pain
Past, Present and Future
Robert W. Baloh
123
Sciatica and Chronic Pain
Robert W. Baloh
Sciatica and Chronic Pain
Past, Present and Future
Robert W. Baloh, MD
Department of Neurology
University of California, Los Angeles
Los Angeles, CA, USA
ISBN 978-3-319-93903-2 ISBN 978-3-319-93904-9 (eBook)
https://doi.org/10.1007/978-3-319-93904-9
Library of Congress Control Number: 2018952076
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Foreword
In Sciatica and Chronic Pain: Past, Present and Future, Professor Baloh addresses
a common, universal problem directly related to man’s upright posture. As such, it
has afflicted man since prehistoric times. Our understanding of sciatica and pain has
evolved over time. Modern imaging has contributed greatly to our appreciation of
the relationships of nerve roots contributing to the sciatic nerve and the importance
of adjacent structures of bone, cartilage, and disc. Our understanding of the phe-
nomenon of pain and its physiology and chemistry is perhaps less complete.
Management of patients with sciatica and chronic pain still poses a major challenge.
Surprisingly, few have attempted to address this important problem.
Our perception of pain and response to pain is very individual and differs widely
among people. Sciatica and Chronic Pain: Past, Present and Future delves into dif-
ferent aspects of pain from neural networks, neural transmitters, and genetic view-
points and provides us with a glimpse of how various factors may interact to make
us perceive pain. This book also provides a concise yet complete guide to the man-
agement of patients with sciatica. It explores the multifaceted approach to manage-
ment of chronic pain from many viewpoints, including of course the pharmacological
and surgical, as well as less orthodox approaches to pain. As such, it should be of
interest to a wide audience, including students, physicians, as well as patients.
The historical perspectives are not only of interest but allow us to infer that our
understanding of pain mechanisms will expand with current and future research, no
doubt leading to even better methods of pain management.
Ulrich Batzdorf, MD
Professor of Neurosurgery
David Geffen School of Medicine at UCLA
Ronald Regan Medical Center
Los Angeles, CA, USA
v
Preface
I noticed a burning pain in my right buttock one Sunday morning. Since I frequently
injured myself during my weekly tennis match on Saturday, at first I was not con-
cerned. I tore my rotator cuff in the past and after surgical repair I could only play
once a week without reinjuring the shoulder. But the pain gradually got worse and I
noticed occasional sharp pains shooting into the outside of my right leg. I thought
the pain might be coming from my hip possibly arthritis of the hip since my father
had severe arthritis of the hip as he got older and I am a big believer in genetics. But
when I saw the orthopedic surgeon who repaired my rotator cuff tear, he could not
find anything wrong with my hip. We agreed that the pain was probably sciatica due
to arthritis in my back and that I should lay off tennis and take ibuprofen as needed
for the pain.
At least 5% of the general population suffers from sciatica and about 10% have
some type of chronic neuropathic pain. Sciatica is the most common cause of
chronic neuropathic pain, yet there is no consensus on how to manage this common
painful disorder. Treatments developed thousands of years ago are still in common
use. I am a professor of neurology at the University of California in Los Angeles and
I have been teaching general neurology to medical students and neurology residents
for more than four decades. I have treated many cases of sciatica over the years and
I am well aware of the controversies regarding best treatments. In this book, I
address the following questions from the point of view of a clinical neurologist, a
teacher of neurology, and a person who has experienced sciatica.
• How is pain detected and perceived?
• What is sciatica and what are the causes?
• What are the treatment options for new onset sciatica?
• Why does the pain persist in many cases?
• What are the treatment options for chronic pain?
• And what new treatments are on the horizon?
The goal of the book is to provide a concise overview of sciatica and chronic
pain. I have a longstanding interest in the history of medicine and I use historical
context to set the stage for understanding new concepts. As in all areas of
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viii Preface
neuroscience and medicine, there is a “jargon” that goes with the field. I have
attempted to minimize the impact of the jargon on understanding new concepts by
defining terms as they are introduced. Charts, figures, and tables help clarify new
concepts. Finally, three patients with sciatica and chronic pain are followed serially
throughout the book to illustrate important concepts discussed in the text.
Robert W. Baloh, MD
Distinguished Professor of Neurology
David Geffin School of Medicine at UCLA
Ronald Regan Medical Center
Los Angeles, CA, USA
Acknowledgments
I thank my neurology colleagues Melissa Spencer and Leif Havton for reviewing
early drafts of the book and providing helpful comments. I want to particularly
thank Rick Batzdorf for his helpful suggestions and for writing the Foreword to the
book. I thank Julie (Juhyun) Kim for drawing several of the figures and her patience
in getting them just right. Julie is a nurse practitioner at Mount Sinai Hospital in
New York and a talented young medical illustrator. My wife, Grace, provided
helpful suggestions and constant support. Finally, I want to thank Michael Griffin
and Richard Lansing at Springer for helping me get the book together.
ix
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Overview of Pain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Neuropathic Pain and Sciatica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Content of the Book . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Suggested Additional Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Nerves and the Detection and Perception of Pain . . . . . . . . . . . . . . . . 5
Early Ideas on How Pain Was Detected . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Specific Nerves for Perception of Pain . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
How Do Free Nerve Endings of Pain Fibers Detect Noxious Stimuli? . . 10
Pain Fibers in Nerve Sheaths (Nervi Nervorum) . . . . . . . . . . . . . . . . . . . 12
Nerve Regeneration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Brain Pain Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
How Does the Brain Perceive Pain? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Pain as an Emotion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Suggested Additional Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3 What Causes Sciatica? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Structure of the Spine and Sciatic Nerve . . . . . . . . . . . . . . . . . . . . . . . . . 22
Identifying the Cause of Sciatica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Overview of the Common Causes of Sciatica . . . . . . . . . . . . . . . . . . . . . 23
Distinguishing Between Common Causes of Sciatica . . . . . . . . . . . . . . . 24
Causes of Rapid Onset Sciatica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Herniated Discs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Spondylolisthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Infections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Causes of Gradual Onset Sciatica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Osteoarthritis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Tumors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Nerve Entrapment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
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xii Contents
Illustrative Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Case 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Comment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Case 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Comment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Case 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Comment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Suggested Additional Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4 Initial Management of Sciatica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Evidence Based Treatments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Pain Medications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Anti-inflammatory Drugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Opioids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Cannabis (Marijuana, Indian Hemp) . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Muscle Relaxants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Liniments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Physical Therapy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Alternative Medicine Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Spinal Manipulations and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . 40
Acupuncture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Overview of the Management of New Onset Sciatica . . . . . . . . . . . . . . . 43
Illustrative Cases Continued . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Case 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Comment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Case 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Comment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Case 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Comment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Suggested Additional Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
5 Imaging the Back and Sciatic Nerve . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Strategy for Imaging the Back in Patients with Sciatica . . . . . . . . . . . . . . 49
Overview of Current Techniques for Imaging the Back . . . . . . . . . . . . . . 52
Routine X-Rays of the Spine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Computed Tomography (CT) of the Spine and Pelvis . . . . . . . . . . . . . 52
Magnetic Resonance Imaging (MRI) of the Spine and Sciatic Nerve . 52
Illustrative Cases Continued . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Case 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Comment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Case 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Comment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Case 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Comment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Case 3 Continued . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Comment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Suggested Additional Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56