Treatment is dependent upon the mechanism of the injury (high velocity vs. low velocity) and any associated neurological deficits.
Mild Head Injury
The majority of children who seek medical attention after a low-velocity head injury fall into the mild injury category. Although there may be a history of a brief loss of consciousness and/or amnesia for events surrounding the injury (i.e., concussion), these children are usually awake, possibly confused (disoriented or, according to a parent, "not acting right") and complain of headache, nausea and vomiting. The great majority of these children do not require hospitalization or treatment, and make an uneventful, full recovery (see discussion of neuropsychological sequelae).
Children with mild head injuries often present a difficult problem with regard to the extent of diagnostic testing required. The use of CAT scan and skull X-rays for all children with mild head injuries would be costly and have little therapeutic yield. Children who have mild symptoms such as headache and dizziness and minimal signs of injury to their scalp do not require these examinations. Following a concussion, plain skull X-rays are only performed when there is evidence of scalp trauma. Discharge information that describes appropriate "home examination" can be printed on a head injury sheet and given to the family member observing the child.
An "impact seizure" may be associated with a mild injury (as when a child is struck by a swing) and is not correlated with a brain injury or epilepsy. Although a concussion is not associated with a significant brain injury, there are occasionally a variety of disturbing symptoms that may persist for a few days or even weeks following the injury. These include headache, dizziness, memory impairment and problems with concentration. The latter may be most pronounced in school and result in poor academic performance. It is important to reassure the child and teacher that these symptoms, when present, will completely resolve.
A dilemma that we have difficulty in resolving is whether or not an adolescent who has suffered a concussion in football should be permitted to return to this vigorous contact sport following a complete recovery. Studies have indicated that a second head injury even of a mild nature places the child at a much greater risk for the development of long-term neuropsychological deficits. Although it is difficult to restrict a child's behavior, the parents and patients must be aware of potential consequences of a second head injury so that they may make an informed choice.
Moderate Head Injury
Children who have sustained a moderate head injury are usually confused or sleepy but still able to follow commands upon neurological examination. A CT scan and skull X-rays are done after hospital admission looking for indications of masses impinging on the brain and thus impairing its function. When mass lesions are discovered, they are typically removed surgically if it is felt that they are impairing the brain's function. The child is then supported in the hospital during the early period of recovery. Although most children in this group make a complete recovery, some may have long-term neuropsychological difficulties that require follow up. These sequelae, which are identified on neuropsychological evaluation, may include short- and long-term memory deficits, difficulty with abstract thinking, behavioral problems and decline in social skills.
Severe Head Injury
Diffuse axonal injuries are a component of high-velocity head injuries. These injuries are associated with both rotational and linear acceleration/deceleration upon impact, giving rise to shearing forces within the brain that disrupt anatomy diffusely. These injuries begin at the surface of the brain and extend centripetally toward its center and base (the diencephalon and brain stem). Although the anatomic basis of a rotational injury is difficult to visualize with radiologic studies, the associated clinical dysfunction is often severe. The child with a severe head injury has a Glasgow Coma Scale less than 9 and is unable to follow simple commands because of impaired level of consciousness. Morbidity and mortality can be dramatically reduced through rapid and aggressive clinical management. In discussing severe head trauma, one must consider the effects of primary vs. secondary brain injury. The primary injury occurs at the moment of impact. The severity of the injury is directly proportional to the amount and kind of biomechanical stress transmitted to the cranium and the brain.
The secondary injury results from the subsequent events that exacerbate the effects of the primary injury. Potentially reversible lesions are made permanent, and new lesions occur from such events. Systemic hypotension (low blood pressure), hypercarbia (elevated blood carbon dioxide) and hypoxia (low blood oxygen) result in brain ischemia (oxygen deprivation) and edema (swelling). All these processes, if not reversed, will result in anoxic damage (irreversible brain injury due to oxygen starvation) and progressive functional deficits. These children are most often managed in an intensive care unit (ICU) by a neurosurgeon and a pediatrician. Primary treatment includes stabilization of the body's vital functions, insertion of a breathing tube for controlled ventilation, and treatment of increased pressures within the brain (this can include surgical removal of any threatening mass lesion, hyperventilation and diuretics to lessen brain swelling). Intracranial pressure monitoring (requiring the surgical insertion of a device to measure pressure inside the skull) may be utilized to monitor the effectiveness of the medical and surgical treatment.
Recovery from severe head injury is dependent upon the severity of injury, rapid initiation of medical treatment, and rehabilitation. Recent studies of severely head-injured children indicate that both morbidity and mortality are dramatically reduced with aggressive medical and surgical management. Physical, occupational and speech therapy begin in the severely head injured child once the child's clinical condition allows. The severely head-injured child may be hospitalized for weeks or months in an acute care setting followed by an extended stay in an inpatient rehabilitation center. While in these facilities, the children are frequently evaluated in terms of physical and neuropsychological recovery, with discharge planning based upon the individual's progress. It has been recognized that children who make a "good" neurological recovery from a moderate or severe head injury have difficulties with memory and intellectual functioning. Specialized neuropsychological follow-up is necessary for all of these children, with ongoing intervention aimed at maximizing recovery.