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When Brain Injury Occurs
by Dennis P. Swiercinsky, Ph.D., ABPN
Traumatic brain injury occurs when a physical force to the head causes the brain to suddenly and violently slam against the interior bony structure of the skull. Trauma to the head can cause nerve cells in the brain to stretch, tear, and pull apart, making them unable to relay messages from one part of the brain to another. The head striking an object (a windshield or the ground) at a fast rate of speed or something striking the head (a flying or falling object) can cause brain injury.
Brain injury does not have to
involve direct trauma to the head. Whiplash injury or violent shaking of the
head can also cause brain injury. Injury to brain cells interferes with all
sorts of information processing— thinking, remembering, seeing, controlling
and coordinating bodily movements, and controlling emotions. Traumatic brain
injury can range from relatively mild to catastrophically severe depending on
multiple factors including degree of force, multiple trauma, neurological
complications, and timeliness of emergency medical treatment.
Mild Traumatic Brain Injury
Clinicians classify head (or, more
correctly, brain injury) based on quality or length of change in
consciousness and length of amnesia (memory loss). Both loss of consciousness
(or even a semi-conscious state) and amnesia are directly caused by the sudden
trauma and tearing of nerve cells. When this trauma occurs, the brain simply
cannot maintain its normal functioning and shuts down (causing unconsciousness)
or partially shuts down (causing a feeling of being dazed), until cellular
functioning can recover. "Mild brain injury" refers to the extent of
loss of consciousness (30 minutes or less) and length of amnesia (24 hours or
less), not to the functional effects. The diagnosis can be made if even
one of the following conditions is observed: (1) loss of consciousness of any
length, (2) amnesia of any length, (3) altered consciousness (e.g., being
"dazed"), or (4) focal neurological deficits (e.g., temporary vision
loss, or a seizure). Even a " mild" traumatic brain injury can result
in permanent, life-altering consequences.
Effects of Traumatic Brain Injury
Some of the functional consequences of mild traumatic brain injury include slowed thinking, memory and concentration problems, poor judgment, emotional disorder, and difficulty making decisions. These problems are a result of "diffuse axonal injury," or damaged nerve cells. This type of injury impacts the processing of electro-chemical messages within the brain, leading to the destruction of previously existing complex interrelated brain connections. As a result, complex or unfamiliar tasks become frustrating, irritability prevails, and the person attempts to cope with a brain that just seems always to function in a mental fog. A wide variety of complicating cognitive and emotional reactions can evolve— some of which may be permanent.
Effects of traumatic brain injury
vary from one person to another. Both the physical nature of the injury and the
personal characteristics and resources of the individual contribute to the
functional difficulties. Some individuals may recover relatively well while
other may experience major life-altering effects.
Diagnosis of Traumatic Brain Injury
X-ray, MRI (magnetic resonance
imaging), and CT (computerized tomography) can sometimes diagnose head and brain
injuries by showing areas of fracture, hemorrhage, or other kinds of tissue
injury. These techniques are usually employed initially in the case of any head
trauma to check for life threatening bleeding or swelling in brain tissue.
However, traumatic brain injury (especially if mild) often involves scattered
disconnection among neurons and supportive tissue, stretched and damaged axon
membranes (known as diffuse axonal injury), chemical injury due to
neurotransmitter toxicity, and cellular dysfunction due to changes in brain
chemistry. These kinds of changes to brain cells often do not result in
sufficient change in the tissue density to be detected by conventional imaging
techniques. Even if diffuse axonal injury does cause some subtle change in
tissue density, the injury is so scattered throughout the brain that there is
insufficient focal concentration of injury to yield detection by these
procedures. Often, more elaborate imaging techniques such as SPECT
(single-photon emission computed tomography) or PET (positron emission
tomography) can detect changes due to brain injury because these techniques
measure brain cell metabolism, not tissue density. In addition to these imaging
techniques, a variety of neurological and behavioral tests are used to diagnose
Due to the typically diffuse
nature of many cases of brain injury, structural changes may not be easily
detected by conventional imaging procedures. However, traumatic brain injury
also causes behavioral or functional changes. Assessing functional change is a
major procedure for diagnosing brain injury. Objective and scientifically
created neuropsychological tests are sensitive to these trauma-induced
functional changes and sometimes provide the best—and only—technique for
revealing brain dysfunction. By combining data from a thorough interview and
results of neuropsychological and sometimes personality tests, the
neuropsychologist creates a functional profile that can be compared to the kinds
of profiles usually produced by persons with various kinds of brain injury.
Neuropsychological examination also differentiates emotional and personality
changes (such as depression or posttraumatic stress disorder) from
The Role of the Neuropsychologist
Only specifically trained
psychologists who specialize in neuropsychology (the study of brain and behavior
relationships) are qualified to administer and interpret neuropsychological
tests. Neurologists and neurosurgeons often administer a variety of mental
status procedures but these are neither standardized nor sensitive enough to
detect subtle dysfunction that can be revealed by objective neuropsychological
tests. Neurologists, neurosurgeons, and neuropsychiatrists are medical doctors
who rely on physical procedures and trained observations for diagnosis, and
medical/surgical techniques for treatment. Neuropsychologists are clinical
psychologists who, through the use of standardized behavioral assessments, seek
to understand the complex interactions of psychological and biological
components that produce dysfunctional behavior.
Brain injury is diagnosed by comparing the results of neuropsychological tests that are sensitive to changes caused by brain injury with neuropsychological tests that are not sensitive to changes caused by brain injury. Similarly, some procedures differentiate pre-existing emotional and personality characteristics that existed before injury. "Differential Diagnosis" is the hallmark of a comprehensive neuropsychological examination. The neuropsychologist sorts out the pre-existing emotional and psychological factors from the acquired changes due directly to brain injury.
Dr. Dennis Swiercinsky is a nationally recognized neuropsychologist. He has provided neuropsychological examinations, directed brain injury rehabilitation programs and published educational materials for professionals and families regarding the psychological effects of brain injury. He completed his doctorate in rehabilitation psychology in 1974 at the University of Kansas. Since then, he has taught at major universities, provided legal services in more than 300 civil and criminal cases, and conducted private clinical practice for more than 25 years. He was a merit-reviewed researcher for the Veterans Administration for four years, conducting studies on the refinement of brain injury diagnosis. Dr. Swiercinsky specializes in providing comprehensive understanding of brain-behavior relationships and how these relate to daily functioning, disability, personality and behavior, and vocational performance. He is a diplomate in the American Board of Professional Neuropsychology.
Bay Area Psychological Testing
Associates © 2002
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