Child Head Injury - Brain Injury in Children
Unfortunately, head injuries are very common with children, accounting for approximately one hundred thousand hospitalizations annually. Modes of injury include motor vehicle accidents, bicycle accidents, falls, sporting injuries, and child abuse. Certain aspects of brain injury are unique to children. For example, it is more difficult to determine the measure the loss of brain function in a child. In adults there are prior academic records, I.Q. scores, and job histories to rely on. At one time it was assumed that children were more resistant to brain trauma than adults because their developing brains could rewire over time. However, mounting evidence seems to suggest otherwise. In fact, it may be that children are more susceptible than adults to permanent brain damage even when the forces involved are equivalent.
Coup and contracoup injuries
Image demonstrates how in a coup injury a blow to the rear of the skull results in an injury to the anterior of the brain. In a contracoup injury (right), the brain recoils and strikes the posterior skull as well, injurying it twice.
In children some neurologic deficits after head trauma may not manifest for many years. Frontal lobe functions, for example, develop relatively late in a child's growth, so that injury to the frontal lobes may not become apparent until the child reaches adolescence as higher level reasoning develops. Since the frontal lobes control our social interactions and interpersonal skills, early childhood brain damage may not manifest until such frontal lobe skills are called into play later in development. Likewise, injury to reading and writing centers in the brain may not become apparent until the child reaches school age and shows signs of delayed reading and writing skills.
Maintaining vascular stability after head trauma can be a difficult feat in children. On occasion, a head injury can trigger a sudden dilation of all cerebral blood vessels, resulting in a massive influx of blood into the head. All the extra blood and associated cerebral edema it causes can raise intracranial pressure over the course of hours to fatal levels. These children seem normal after the accident but within a few hours lose consciousness as intracranial pressure rises.
Recent studies show that children's skulls are only 1/8 as strong as that of adults. Thus, children are much more vulnerable to injury through deformation and fracture of the skull, which can injure the brain.
In adolescents, the effects of brain injury are often difficult to distinguish from the normal anxiety and behavioral changes that occur as part of adolescent development.
Educational opportunities are guaranteed to mildly head injured children under Federal law 94-142 which protects the rights of learning disabled, retarded and emotionally disturbed children to receive an education. Head injured children are unique in this regard. They are not learning disabled, retarded or emotionally disturbed. While a head injured child may have some difficulty in placement, under the law such children must still be placed in an appropriate setting for their unique problems.
Children Suffer from Increased Ongoing Symptoms vs. Adults
For many years the idea existed in the medical field that equivalent brain damage to a child and an adult would lead to less problems in a child than in the adult. This view came known to be called the "Kennard Principle" based on studies with monkeys (Kennard M.A. 1940). The idea was that a child's brain, while evolving, exhibited "neuroplasticity," enabling it to work around or adapt to organic brain damage. However, many recent studies have shown that the "Kennard Principle" is wrong, and that in fact the outcome for children suffering traumatic brain injury is far worse than the outcome for an equally injured adult. [(Anderson V. and Moore C. 1995) (Ewing-Cobbs L. 1989) (Ewing-Cobbs L. 1994) (Roberts M. A. 1995) (Laurent-Bannier 2000) (Webb C 1996) (Nybo 1999)].
The development of the frontal lobes in a child continues until the age of around 16. Disturbances in this growth can cause subtle but profound problems. Because changes in this area of the brain effect "the executive functions" they effect basically what it is to be human. Unfortunately, some of these changes only become apparent at later stages of development (Oddy M. 1993). The child will confront challenges as he or she grows up, such as increasingly difficult math leading to Algebra, increased difficulty with higher level learning in high school, the challenges of college, and the increasingly difficult and complex social interactions expected of a person approaching adulthood. The problem facing parents is that they will not know how their child will handle these hurdles and whether or not he or she will get past them. In the study entitled "Cognitive Indicators of Vocational Outcome After Severe Traumatic Brain Injury (TBI) In Childhood" it was noted that falls and motor vehicle related accidents account for over 70% of injuries of pre-school children, and often produced diffused closed brain injuries where mostly the frontal areas of the brain are damaged. As the frontal lobes develop rapidly during the first five years of life and continue to mature until late adolescence, the executive deficits caused by these injuries may be subtle and overlooked. Thus, there is the possibility of psycho-social changes becoming apparent later, when more demands are placed on the individual and when the every day situations become more unstructured (i.e. working life in general).
In this study 33 children with severe TBI were followed though adulthood. They noted normal school performance after severe childhood TBI may or may not indicate good vocational outcome. After normal school performance, 8 of 21 patients were able to work independently, 9 were not.....children suffering moderate to severe brain injury prior to age 7 have been shown to be less likely to exhibit recovery with performance IQ scores, which suggests that head injury has more impact on "fluid" intelligence skills. The researchers also found that children may cope better at school since it is a highly structured environment, than they performed in a more independent and less structured modern working environments. In the conclusion of the study, it was noted:
The parents need realistic information about their child's cognitive defects and preserved abilities to avoid false optimism leading to frustrating and exhaustive educational plans. Because of the possibility for delayed vulnerability of executive and information processing skills, low tolerance and emotional instability, reassessment of the disability in adulthood is needed.
In many cases children suffering from TBI can exhibit normal or above average IQ following injury, but can still have profound problems. These children were still unable to organize their lives and make sensible daily decisions. They showed severe problems with the organizational skills of everyday activities despite relatively normal testing results and language and intelligence (Shallice T. 1991).
Unfortunately, the effect of brain injury are to exaggerate pre-accident personality traits and disabilities. As noted in the study entitled "Rehabilitation of Brain Injured Children": (Vannier A., Brugel D.G., DeAgostini M. 1999)
Although it is not possible to determine their frequency precisely, these personality changes seem to be common in clinical practice and are likely to be missed by standard measurements. They may include, as an adult, attention deficit and fatigue, impaired planning and problem solving, lack of initiative, inflexibility, impulsiveness, irritability and temper tantrums, opposition, and socially inappropriate behavior.
One of the common symptoms of traumatic brain injury is that of disinhibition. A person suffering from TBI disinhibition is likely to "speak his mind" and say socially inappropriate things where a normal person might think them but have the sense not to say them. This causes increased difficulty in socialization and advancement as an adult. The other aspect of disinhibition it can also lead to difficulties. That is, it is also commonly associated with addictions to drugs and alcohol. The same mental screens that prevent one from saying inappropriate things would also control primitive appetites for drugs or alcohol. When that is diminished the increased likelihood of addiction frequently occurs.
The authors of "Rehabilitation of Brain Injured Children" make the following statement "this study also strongly suggest that the final assessment of the outcome after childhood should be done in adulthood." Unfortunately, the final assessment in most lawsuits, for example, cannot wait until adulthood. There is no "Kennard Principle" around anymore to give us a rosy outcome for brain injured children. It is in fact the opposite - we must assume that the difficulties currently noted are going to compound themselves and get worse in the future.
A study released in May 2001 shows that millions of children may by at risk for lead poisoning, as even lower levels of lead appear to damage the brain than previously reported. Children between the ages of 1 and 5 years are particularly vulnerable to the brain damaging effects of lead, for three reasons. Below the age of 1, children do not do as much exploring of their environment, finding interesting things to put in their mouth. By the age of 5, the gut is less efficient at absorbing lead. The third reason has to do with how the brain develops between the ages of 1 and 5. Each nerve cell in the brain is made up of a cell body where the nucleus directs the manufacture of proteins and neurotransmitters, an axon down which electricity flows to stimulate the next nerve cell, a terminal bouton which is the tip of the axon where neurotransmitters are stored, and dendrites - "antennae" extending from the cell body where axons release their neurotransmitters to stimulate that nerve cell to fire its axon. Each nerve cell has hundreds if not thousands of dendrites extending from the cell body. Lead prunes the dendrites, reducing the connections between axons. Normally, the dendritic tree is most bushy between between the ages of 1 and 5. It then thins out naturally as we age. The best way to slow this thinning process is to use those nerve cells between the ages of 1 and 5, hence the push for preschool stimulation and education.
Any amount of lead in the bloodstream at this early age is harmful to the brain, and at some point the doctors will recommend that the lead be removed from the body to minimize any further brain damage. Lead is removed by injecting a chemical called EDTA into the bloodstream. Lead attaches to the EDTA which then carries the lead into the urine. However, recent studies have shown that this method of treatment, known as "Chelation Therapy" may not work to improve IQ's.