Traumatic Brain Injury: A Conversation With Dr. Rolland Parker
We will talk today about a traumatic brain injury, which has numerous consequences, often proceeds through a variety of phases, and has multiple consequences.
Brain injury is usually accompanied by injuries to other parts of the body. This is now called by the Armed Forces “POLYTRAUMA”.
Polytrauma will be the topic of a 2-day Conference organized by The New York Academy of Traumatic Brain Injury. It will be held at the Hospital for Joint Diseases, 301 East 17th St., in Manhattan, on March 23, and 24, 2007.
There are two vital topics:
I. Trauma incurred by our armed forces in Iraq, Afghanistan, and Vietnam.
II. The World Trade Center Disaster, known as 9/11.
Topics will be the nature of injuries incurred in a major civilian disaster, and preparation in the event of another occurrence, both civilian activity and medical personnel.
We will have medical and psychological health care and scientific faculty from the Armed Forces, and the Uniformed Services Health University, and medical and academic centers.
There will be an important contribution to preparation for major civilian disaster. Participating will be administrators and treating doctors from the New York University Medical Center, which was the primary provider of services after the Twin Towers were destroyed. This will include representatives of the Chief Medical Examiner’s office, New York Downtown Hospital, within 3 blocks of the disaster, Bellevue Hospital Emergency Department, and Stress Psychologists from Rusk Institute.
Full information can be obtained at WWW.NYACADTBI.ORG
There are various kinds of traumatic brain injury.
1. Physical forces. These include impact between the head and a hard object, acceleration and deceleration of the brain caused by changes in the speed of the body, pressure waves transmitted into the brain which stretches or tears nerve fibers, intra-cellular chemical reactions, and contusion when the brain strikes the enclosing skull and cavitation when it bounces back creating a vacuum.
It is an error to assume that if there is no loss of consciousness, then there is no TBI. Altered consciousness, i.e., loss of memory for the accident, or confusion, is often followed by detectable signs of neurobehavioral dysfunctions. I have observed that the geometry of the injury, i.e., where the impact occurs, and the direction in which the body is moving, as in a fall, may determine whether or not loss of consciousness occurs, even though there are signs of TBI.
There are potentially major or fatal secondary effects caused by hemorrhage, ischemia, swelling, etc.
Eventually, there are long-term developments
- Neurological disorders, such as posttraumatic epilepsy,
- Physiological disorders such as hypopituitarism, or disturbed physiological and sexual development in children.
Here are some events causing traumatic brain injury or TBI.
- We have now become aware of a new cause of TBI, i.e., blast injury. Gunshot and other missile wounds. Military weapons have a higher velocity than civilian guns. Military gunshot wounds are different than the characteristic civilian wound since the velocity of the round is higher. A bullet or other missile does not have to enter the brain or fracture the skull to cause traumatic brain injury. A glancing impact, tangential to the skull, will cause pressure waves to be transmitted it to the brain.
- Falling objects. Remember that it is common that when a heavy object strikes the head, it may simultaneously, or later strike other parts of the body causing permanent injury, e.g., the shoulders, limbs, or spinal column.
- Falls.
- Assault with hard objects or fists.
- Motor vehicle accidents. These involve crashes between cars or with a stationary object or barrier; striking a pedestrian; whiplash injury inside the vehicle. The head attached to the neck and torso is accelerated and decelerated. This can cause significant damage to the enclosed brain through shearing between brain layers, abrasion against the inside of the skull, in , falling objects, falling.
- Repetitive lesser impacts, e.g., football, soccer, and boxing. There was an unhappy event recently in which a football player became depressed and suicidal. We will take a look at it shortly.
In addition to physical forces, there are
2. Electrical injuries, both directly to the nervous system, and as the consequences of the muscular reaction causing a fall;
3. Neurotoxins.
The consequences of traumatic brain injury are multiple:
I. Neurological, Sensorimotor, Cerebral Personality Disorder:
II. Somatic: Performance and Health Disorders Consequent to Soft Tissue Damage, Disturbed Internal Milieu (physiologically based symptoms); Pain; Developmental disorders of children.
III. Mental Control: Information Processing, Executive Functioning, Concentration, Error monitoring.
IV. General Intelligence.
V. Learning and Memory
VI. Personality Style: Psychodynamics, motivation, moods, defenses.
VII. Identity, Insight, Morale, Weltanschauung (world view)
VIII. Empathy and social life
IX. Stress Reactions: Acute/Chronic; Psychological; Physiological; Dissociative
- Brain injury and body injury often occur together.
- Chronic symptoms are frequent, and they reflect unhealed wounds.
- When an injury does not heal promptly certain systems become dysregulated, that is, they continue to function, independently of the ordinary demands of the body in daily living.
These systems are- The immune system which is responsible for wound healing and removal of dead tissue;
- The hormonal system which responds to stress;
- The inflammatory system which controls the acute wound.
- The posttraumatic effects of physiological exhaustion
- The circadian or day/night system. After brain trauma, sleep disturbances are very common and this creates both interference with the pattern of hormonal release, but also fatigue and problems of concentration and attention.
Ordinarily, when there is physical or mental stress, the various systems are coordinated with each other, This is the concept of Allostasis.
However, after an unhealed wound, these systems function indefinitely. They become exhausted, i.e., burnout. Technically this is called an Allostatic Load.
Among the consequences of an injury is reduced efficiency of the blood brain barrier and similar structures intended to keep neuroactive substances from entering the brain. This causes detectable disturbances of brain function which may be mis-attributed to brain damage, but really are the result of the physiological consequences of the chronically unhealed injury.
The consequence of physiological exhaustion of systems is loss of stamina, chronic stress, and vulnerability to a variety of stress-related diseases, e.g., cardiovascular. There are also cognitive and mood disorders consequent to the release of physiological products into the bloodstream, which are then conveyed directly and via the vagus nerve into the less well protected brain.
These are part of the concern of the health care provider treating a brain injured person.
I suggest that when a health care provider concentrates on study and treatment of only the professional aspects within his or her specialty, it is an invitation for errors of omission and errors of commission.
Military casualties: Land mines, improvised explosive devices, rocket propelled grenades. The pattern of injury and neurobehavioral effects are different from earlier wars.
Troops near an explosion may have TBI, even if they did not appear obviously to have an injury. These require special alertness by the health care provider. Cognitive loss may not be obvious, until they return to civilian or other responsibilities and cannot perform.
Blast: The troops are wearing helmets, and body armor, tending to concentrate the blast to the face, head, and neck. 59% get a diagnosis of TBI.
Frontotemporal brain; eardrums, fingers, and limb injuries, eyes, speech, cognition, spinal column, lungs, heart, abdomen.
Stress: Unexpected violent injury, unseen or unpredicted assailants. 20% of troops returning from Afghanistan and Iraq met criteria for posttraumatic stress disorder (PTSD). Flashbacks; depression.
Repetitive lesser trauma, e.g., boxing (dementia pugilistica), football, soccer, and winter sports.
- Blunt head trauma:
- Causes these signs: pyramidal; extrapyramidal; cerebellar.
- Disorders with clinical and pathological features similar to Alzheimer’s disease.
- Chemical studies suggest there is global dysregulation of Aluminum and iron transport in dementia pugilistica and Alzheimerís disease.
- There may be a pattern of neurofibrillary degeneration similar to Downs Syndrome (genetic), Dementia pugilistica (environmental and Alzheimers disease.
- Depression is often seen in traumatic brain injury. However, the name “depression” is given to disparate causes: reaction to being injured and impaired, high secretion of the stress hormone Cortisol, damage to the left frontal area, endocrine disturbances such as low thyroid secretion, etc.
- The statement that after certain kinds of “minor” traumatic brain trauma there is “no cognitive decline” can be made with reasonable accuracy only when these conditions are met:
1. A wide range of examination, in order to increase the probability of detecting an area of dysfunction or loss.
2. Determination of a baseline, thus whether there is any deviation from the pre-injury level.
3. Waiting a few years after the injury to determine whether there is development of late neurological, physiological or other stress signs. - Repeated TBI may cause the same chemical changes as those occurring in Alzheimerís disease.
- Repeated blows may cause the accumulation of both direct damage and the potential for later development of neurobehavioral symptoms of TBI.
Discussion
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