V ISION
REHABILITATION
Multidisciplinary Care of the
Patient Following Brain Injury
V ISION
REHABILITATION
Multidisciplinary Care of the
Patient Following Brain Injury
Edited b y
Penelope S. Suter
Lisa H. Harvey
Boca Raton London New York
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Contents
Foreword .................................................................................................................. |
vii |
Preface....................................................................................................................... |
xi |
Acknowledgments.................................................................................................. |
xiii |
Editors...................................................................................................................... |
xv |
Contributors ........................................................................................................... |
xvii |
Chapter 1 What Is Vision Rehabilitation Following Brain Injury? ...................... |
1 |
Penelope S. Suter, Lynn F. Hellerstein, Lisa H. Harvey, and |
|
Katharina Gutcher |
|
Chapter 2 The Interdisciplinary Approach to Vision Rehabilitation |
|
Following Brain Injury....................................................................... |
31 |
Amy Berryman and Karen G. Rasavage |
|
Chapter 3 Neural Substrates of Vision................................................................ |
45 |
Richard Helvie |
|
Chapter 4 Spatial Vision ..................................................................................... |
77 |
Robert B. Sanet and Leonard J. Press |
|
Chapter 5 Evaluation and Treatment of Visual Field Loss and |
|
Visual-Spatial Neglect...................................................................... |
153 |
Neil W. Margolis |
|
Chapter 6 Egocentric Localization: Normal and Abnormal Aspects............... |
193 |
Kenneth J. Ciuffreda and Diana P. Ludlam |
|
Chapter 7 The Use of Lenses to Improve Quality of Life Following |
|
Brain Injury ...................................................................................... |
213 |
Paul A. Harris |
|
Chapter 8 Photophobia, Light, and Color in Acquired Brain Injury ................ |
283 |
Cathy D. Stern |
|
v
vi |
Contents |
|
Chapter 9 |
The Vestibular System: Anatomy, Function, Dysfunction, |
|
|
Assessment, and Rehabilitation........................................................ |
301 |
|
Velda L. Bryan |
|
Chapter 10 |
Evaluation and Treatment of Vision and Motor Dysfunction |
|
|
Following Acquired Brain Injury from Occupational Therapy |
|
|
and Neuro-Optometry Perspectives ................................................. |
351 |
|
Janet M. Powell and Nancy G. Torgerson |
|
Chapter 11 |
Acquired Brain Injury and Visual Information Processing |
|
|
Deficits.............................................................................................. |
397 |
|
Sidney Groffman |
|
Chapter 12 |
Vision Examination of Patients with Neurological Disease and |
|
|
Injury ................................................................................................ |
427 |
|
Thomas Politzer and Penelope S. Suter |
|
Chapter 13 |
Successfully Incorporating Vision Rehabilitation into the |
|
|
Primary Care Vision Practice .......................................................... |
461 |
|
Allen H. Cohen |
|
Chapter 14 |
Advocating for Your Patient in the Legal System............................ |
483 |
|
Joseph Kiel |
|
Glossary ................................................................................................................ |
|
493 |
Foreword
One of the most important functions of our brain is to integrate the information from all our senses into a perceptual whole. Only then can we perceive the world as single, integrated, and stable, allowing us to move through it, molding it to our needs and desires. Brain injury shatters this wholeness. Half of one’s visual field may be lost or, stranger yet, one may lose awareness of the left side of one’s body and everything else to one’s left. The eyes may no longer work together resulting in diplopia, visual confusion, and in an impaired spatial sense. Eye movements may not correlate with movements of the head and body, thus, disrupting one’s sense that the world is fixed and stable. Balance and coordination may be disturbed, and reading impossible for the words on the page may appear to be written in a foreign alphabet. One may struggle to come up with the right words or to understand their meaning, and the ability to concentrate and work out these problems may be lost. As L. Zazetsky writes in A. R. Luria’s book The Man with a Shattered World,1 “Ever since I was wounded, I haven’t been able to see a single object as a whole—not one thing…. I’ve had a hard time understanding and identifying things in my environment. What’s more, when I see or imagine things in my mind (physical objects, phenomena, plants, animals, birds, people), I still can’t think of the words for these right away. And vice versa— when I hear a sound or a word I can’t remember right off what it means.” For the past century, conventional wisdom held that the adult human brain is immutable. Most of its circuitry is laid down by early childhood with little possibility, it was thought, of rewiring in adulthood. Great emphasis was placed on the role of “critical periods” in early life for the development of basic perceptual and language skills. Once these critical periods were passed, little neuronal reorganization was possible. A damaged adult brain could not recover. If the brain were injured, the best one could hope for was to develop new strategies to compensate for the functions and skills that were lost.
Despite this mindset, evidence for adult brain plasticity continued to surface and resurface in the scientific and medical literature throughout the last and current centuries. In 1967, Jerzy Konorski in his book, Integrative Activity of the Brain,2 coined the term neuroplasticity, as “the capacity to change its [the brain’s] reactive properties as the result of successive activations.” Also in the 1960s, Joseph Altman published a series of papers demonstrating a striking form of plasticity, the birth of new neurons in the brains of adult rats.3 His findings were totally ignored. Fifteen years after Altman’s first paper, Michael Kaplan confirmed Altman’s discoveries, but he was attacked for his iconoclastic claims and left the research field. Starting in the
1980s, however, scientific investigations confirmed neurogenesis first in the brains of adult birds and later in mammals, including primates. After approximately 30 years, the dogma that no new neurons are born in the adult mammalian brain was finally put to rest. Moreover, recent brain imaging experiments as well as studies revealing
vii
viii |
Foreword |
the mechanisms of synaptic plasticity have contributed to a new view of the adult brain as dynamic and plastic.
Long before it was accepted by the majority of medical doctors and scientists, optometrists recognized the potential for rehabilitation and recovery in the adult brain. While conventional wisdom suggested that normal binocular vision and stereopsis must develop during a critical period in early life, optometrists, including Frederick Brock and William Ludlam, devised therapies in the mid-1900s that taught adults with infantile strabismus how to fuse and develop stereovision. They recognized that changes in the adult brain require active learning, involving attention, practice, and feedback. While an infant nervous system may change its connections in response to any strong stimulus, an adult brain is pickier. It rewires specifically in response to behaviorally relevant stimuli. The degree of functional improvement or recovery in an adult depends in large part on the motivation of the individual and the design of the therapy.
These insights are critical for the treatment and rehabilitation of the growing number of victims of acquired brain injury, including cerebral vascular accidents, traumatic brain injury, and progressive neurological disease. Most alarmingly, traumatic brain injury is the “signature injury” sustained by servicemen fighting in the current wars in Afghanistan and Iraq. And even a concussion, what has been labeled as mild traumatic brain injury (mTBI), can have serious, long-term consequences.
Up until the 1980s and continuing to a large extent to this day, optometrists and the visual rehabilitation that they provide have not been part of the medical rehabilitation efforts of patients with acquired brain injury. Physical or occupational therapy may proceed without thorough attention to visual skills. This situation results in part because of the covert nature of visual injuries. As discussed throughout this book, visual guidance of movements proceeds largely subconsciously so that we are unaware of vision’s role. Thus, problems with maintaining or switching attention may result from difficulties with fixations, saccades, and smooth pursuits. Convergence insufficiency and accommodative dysfunction may manifest themselves as problems with reading. Visual f ield defects or anomalous egocentric localization (midline shifts) may be disguised as movement and balance problems. Difficulties using escalators or an inability to tolerate crowds may result from a poor spatial sense, which results in turn from impaired binocular function. Zazetsky writes in The Man with a Shattered World, “After I was wounded, I just couldn’t understand space, I was afraid of it. Even now, when I’m sitting next to a table with certain objects on it, I’m afraid to reach out and touch them.”
A publication in 2005 gave optimism that awareness of the crucial role of optometry in the rehabilitation of brain injury was increasing. An entire issue of Brain Injury Professional, the official publication of the North American Brain Injury Society, was devoted to neuro-optometric rehabilitation.4 This signaled that a comprehensive book dedicated solely to the growing body of knowledge in this area was due. A large part of this book is devoted to an explanation of the therapy techniques developed by optometrists to improve binocular vision, visual attention, form perception, spatial awareness, spatial reasoning, speed of information processing, visual memory, multisensory integration, and visual-motor skills. In addition, the use of lenses, prisms, yoked prisms, and partial occluders are discussed for the treatment
Foreword |
ix |
of photophobia, visual field loss, anomalous egocentric localization, and diplopia— all common consequences of acquired brain injuries. Moreover, this book provides detailed information on the visual and vestibular systems, differential diagnosis, guidelines to the optometrist for working with an interdisciplinary medical team both in a hospital setting and in private practice, and advice for advocating for the patient in the legal system.
Vision Rehabilitation: Multidisciplinary Care of the Patient Following Brain Injury is a call to action. Optometrists trained in vision rehabilitation must play a fundamental role in the treatment of patients with acquired brain injury. And beyond diagnosing visual deficits and prescribing therapies, the optometrist must listen to the subjective experiences of the patient. Acquired brain injury, by disrupting some brain areas and leaving others intact, produces symptoms that are as unique and remarkable as they are tragic. Zazetsky, the patient who is quoted and described in The Man with a Shattered World, was wounded by a single bullet that ripped through the parietal-occipital region of his brain. He could write but had great trouble reading his own words or those of others. Thoughts and images appeared to him at random and were lost in the next moment. Yet, with his uninjured frontal lobes, he was keenly aware of his deficits and failures, a situation that tormented him for the rest of his life. Each patient with a brain injury has a unique story that must be heard. Above all, rehabilitation of the brain-injured patient must strive to restore to the individual his or her sense of wholeness, of being a complete and functional human being in a fixed and stable world.
Susan R. Barry, PhD
Author of Fixing My Gaze
Professor of Biological Sciences and Neuroscience
Mount Holyoke College
South Hadley, MA
REFERENCES
1.Luria, A. R. (1987). The Man with a Shattered World. Cambridge, MA: Harvard University Press.
2.Konorski, J. (1967). Integrative Activity of the Brain. Chicago, IL: The University of Chicago Press.
3.Gross, C. G. (2009). Three before their time: neuroscientists whose ideas were ignored by their contemporaries. Experimental Brain Research, 192, 321–334.
4.Special Issue on Neuro-Optometry. (2005). Brain Injury Professional, 2(3), p. 1–31.