Mild head trauma without neurologic symptoms is referred to in the literature as “head injury.” When there are symptoms, it is usually referred to as “brain injury.” A mild injury, referred to as a concussion, can result in brief loss of consciousness for a few seconds or minutes, or a person may remain conscious the entire time.
Head injury is a significant public health problem. Head injuries occur frequently in children and, therefore, account for a large number of children’s visits to emergency rooms. The majority of pediatric head injuries are mild. Children with cases of very mild head trauma without symptoms may not seek medical evaluation, thus the exact number of these is not known. Many mild injuries go unreported. Most brain injuries in children under the age of five years are sustained in falls. In older children, most are related to recreational activities, particularly bicycles. Car accidents are also reported frequently, often a car hitting a child, pedestrian or bicyclist. In cases of severe brain injury, motor vehicle accidents are the predominant cause. Child abuse is estimated to account for about 10 percent of pediatric head injuries, with an even higher percentage in infants. However, it is thought that the numbers may be higher because many cases of abuse go unreported or may be misclassified.
The pathophysiology of head injury is not well understood, but it is presumed that there is transitory brain cell damage to the axon glia and blood vessel structures within the brain. Experts believe that rotation – acceleration forces may be mainly responsible for those effects.
The nature of injury in very young children may be different from that seen in adults. The child’s skull’s flexibility, the softer consistency of the younger brain and the relatively large head size, along with poor head control, appears to make young children more vulnerable to minor injuries. It is thought, for example, that infants and toddlers may develop brain swelling more readily, also due to the higher metabolism rates of the brain in these high growth periods of development. There is rapid maturation of the brain and the skull after age two years, and it is thought that by 10 years old the skull and brain structures of children likely respond to trauma in a similar fashion as adults.
Causes/Risk Factors for Head Injury
Boys are more likely to sustain head injuries than girls, especially after age five years. This may be related to differences in boys’ behavior patterns and exposure to risks. Risk factors in the general population may include inadequate supervision, misinformation, not enough information about and/or disregard for prevention strategies and exposure to hazardous or risky environments, such as high-rise apartments and residences near heavy and fast moving traffic. Hyperactivity has also been noted to be a risk factor for some youngsters.
Sports injuries are common. Severe brain injury to young athletes is very rare, especially before age 12 years. Minor head injuries do occur, however. The potential for long-term impact of minor concussions in young athletes is not very well known. There is a specific concern with “second impact syndrome.” In this entity, an athlete has a mild head injury, recovers uneventfully and then some time within the next week has another seemingly mild head injury, but rapidly may develop brain edema (swelling) with a significantly negative outcome. It is felt by experts that there may be a compounding effect of consecutive mild injuries due to residual mild brain swelling. According to some studies, it appears that some athletes who sustain one minor head injury may be at a significantly increased risk of sustaining a subsequent head injury. There are published guidelines in the sports medicine literature to help assess and give recommendations as to when injured athletes should return to play; however, the overall success of those guidelines in preventing negative outcomes is not well confirmed. Neuroimaging may be very appropriate even with a mild injury in any athlete who may have persisting symptoms before s/he is cleared to return to play.
Examination and Testing of Traumatic Brain Injury in Children
Assessment of the severity of an injury relies on clinical evaluation of the child, usually in the emergency room setting, or primary care physician’s office. Evaluation scales, such as the Glasgow Coma Scale, are utilized. Several adaptations of the initial Glasgow Coma Scale are used for young children; however, these are not yet validated. The duration of unconsciousness and a period of posttraumatic amnesia after a brain injury are parameters to be aware of in the evaluation of a head injury.
In the acute clinical setting, the decision for brain imaging is arrived at depending on the clinical condition of the patient, for example, if there is a depressed skull fracture or an abnormal neurologic exam. Neuroimaging is also more frequently indicated in children under the age of two years, as they may be at greater risk for intracranial lesions.
Concussion refers to an alteration in mental status after a blow to the head. Loss of consciousness may or may not occur with a concussion. The main features of a concussion may include confused facial expression, slow reaction to answering questions or following directions, distractibility, disorientation, incoherent or slow speech production, poor coordination, emotionality and memory difficulties. In the following days to weeks the child may experience a variety of symptoms, such as headache (mild usually), poor attention and concentration, irritability, easy fatigability, anxiousness, auditory intolerance, sleepiness, etc. Focal or generalized seizures may occur 1 or 2 hours after head injury. Seizures may happen even in children who did not lose consciousness. These seizures rarely portend future epilepsy.
Specific treatment strategies depend on the degree of injury and symptoms.
Prevention of Traumatic Brain Injury in Children
The neurologist’s role is not only to assess the patient regarding degree of injury and recommend treatment and follow-up, but also to assist with the prevention of traumatic brain injuries in children.
Specific preventive strategies, which have been distinctly successful, include:
1. The use of bicycle helmets. Bicycle helmet use has shown to decrease the risk of head injury by 85% and the risk of brain injury by 88%.
2. Increased use of seat belts and infant car seats has also reduced the risk of brain injury fatalities from car crashes.
3. Education regarding the risk of using baby walkers, which frequently leads to falls down stairs, and, therefore, injury, has also provided improvement in the statistics regarding head injury.
4. The role of the neurologist, as well as other medical staff, also includes education regarding child abuse.
Outcomes of Traumatic Brain Injury in Children
The outcome from a mild head injury is usually good. Symptoms beyond three months are unlikely, and permanent changes are extremely rare. Difficulties with cognitive functions and behavioral functions tend to resolve within weeks up to three months. Overall, long-term cognitive or behavioral deficits resulting from mild head injury are quite rare.
This may not always be the case, however, with moderate to severe brain injury, which can lead to problems with memory, attention, language, visual/spatial abilities, psychomotor speed and executive functions. Behavioral difficulties with moderate to severe head injury include disinhibition, hyperactivity, impulsivity, lethargy, behavioral regression, aggressiveness and mood disturbances. Those changes are often noted to be exacerbations of premorbid or pre-trauma behavioral patterns, but there can also be new problems.
Treatment of Traumatic Brain Injury in Children
Treatment options for patients with head injury and post-concussive syndrome have blossomed over the last few years. These reflect different specialties, such as occupational therapy, physical therapy, speech and language therapy, behavioral psychology and educational specialists. The practical challenge is to coordinate the patient’s care so that the different specialists function together as a team. Minneapolis Clinic of Neurology Concussion Rehabilitation allows for a coordinated, collaborative approach to therapies in conjunction with medical management by the neurologist. The main goal is to do no harm. The overall attitude of caregivers, including family, appears to be a significant factor in the recovery of a patient with a head injury. All efforts should be made to return the patient to mainstream, even if some deficits or difficulties persist.
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