Manifestations and Outcomes of Pediatric mTBI

Each year in the U.S., nearly 500,000 children between the ages of zero and fourteen report to the Emergency Room related to head trauma (Langolis, Rutland-Brown, & Thomas, 2005). Current estimates show that 180 of every 100,000 children under the age of fifteen are diagnosed with traumatic brain injury (TBI) each year (Kraus, 1995). The majority of these are clinically diagnosed as having “mild” traumatic brain injuries (mTBI; Aitken et al., 1998; Langolis, Rutland-Brown, & Thomas, 2005; Lee, 2007).

The highest occurrence of pediatric mTBIs is among children under the age of five and teenagers (Bazarian et al., 2005; Hooper & Baglio, 2001). It is difficult to know if these figures are complete, as it is believed that many mTBIs go unreported or undetected (Buck, 2011). The occurrence of mTBI is likely underestimated historically because a past unavailability of accurate diagnostic criteria made it challenging for clinicians and others to consistently identify and account for mTBI, which lead to misdiagnosis or underreporting (Aitken et al., 1998; Lee, 2007).

Despite this problem, research tells us that pediatric mTBI is often caused by falls, car accidents, bicycle accidents, and sporting accidents (Bazarian et al., 2005; Pondsford et al., 2001; Thiessen & Woolridge, 2006). It is thought that 40-50% of children hospitalized as a result of any TBI may have long-term cognitive, behavioral, or functional deficits (Hawley, Ward, Magnay, & Long, 2004). It is for this reason that evaluation, treatment, and monitoring of mTBI is essential focus of continued study.

Description

Because symptoms and outcomes vary depending on TBI severity, particularly in children, it is important to clarify which injuries are considered here. As a result of diagnostic challenges in the field, in 1993, the American Congress of Rehabilitation Medicine (ACRM) formed The Mild Traumatic Brain Injury Committee in order to establish formal uniform criteria for the diagnosis of mTBI. This was one of the first available clearly-defined standards for mTBI, and is still referenced today. The standard promulgated by the ACRM to define mTBI is as follows:

A person suffers a traumatically-induced physiological disruption of brain function manifested by at least one of the following: (a) any period of loss of consciousness (LOC), (b) any loss of memory for events immediately before or after the accident (posttraumatic amnesia; PTA), (c) any alteration in mental state at the time of the accident, and (d) focal neurological deficit(s) that may or may not be transient but where severity does not exceed the following: (1) loss of consciousness of greater than 30 minutes; (2) after 30 minutes post-injury, an initial Glasgow Coma Scale of 13-15; and (3) posttraumatic amnesia is not greater than 24 hours. (Mild Traumatic Brain Injury Committee, 1993, pp. 86-87)

Diagnosis of mTBI is often a challenge, despite promulgation of standards, as the term mTBI is often used interchangeably with terms such as concussion and minor closed head injury (Kirkwood et al., 2008). It is important to bear in mind that pediatric mTBI is particularly difficult to evaluate, not only because of lack of report, but because brains of pediatric patients are not fully developed and continue to mature post-injury through adulthood.  This makes evaluation, monitoring, and treatment challenging, as functional progress may result from improvement of mTBI symptomology or may result from the patient’s natural brain maturation.

Evaluation

The existence and extent of TBI is diagnosed at the time of injury and classified as mild, moderate, or severe based on a number of relevant factors. These factors have historically included the duration of unconsciousness, the length of the patient’s posttraumatic amnesia, and the outcomes of physical and neurological examinations (which may or may not include neurological imaging; Borg et al., 2004).

The most common and widely used test or scale for clinician evaluation of TBI is the Glasgow Coma Scale (GCS). This scale was originally developed by Teasdale and Jennett (1974) to uniformly and reliably assess patients’ TBI severity. Scores on the GCS range from 3-15, resulting from aggregation of individual scores on three subscales that assess verbal responses, motor responses, and eye opening.

Injury severity is classified as: mild (score of 13-15 with no skull fracture), moderate (score of 9-12 or a score of 13-15 with a skull fracture), or severe (score of 8 or less; Wassenberg, Max, Lindgren, & Schatz, 2004).  Thus, discussion of pediatric mTBI by definition focuses on youth who are diagnosed with a TBI scored between 13 and 15 on the GCS with no associated skull fracture.

Symptoms

Acute signs of pediatric mTBI may include physical, cognitive, and/or behavioral repercussions. Physical symptoms are common and often consist of loss of consciousness, headaches, dizziness, fatigue, nausea, vomiting, sensitivity to noise or light, blurred vision, diplopia, and sleep disturbance (Roberson, 2004). The cognitive impairments involved may include reduced attention, impaired concentration, short-term memory dysfunction, word-finding difficulty, or delayed complex processing. Many patients also experience behavioral changes such as increased aggressiveness, irritability, emotional ability, depression, or anxiety (Blinman, Houseknecht, Synder, Wiebe, & Nance, 2009; Cook, Schweer, Shebesta, Hartjes, & Falcone, 2006; Guerrero, Thurman, & Sniezek, 2000; Taylor et al., 2010).

Research has shown that there is a cluster of symptoms which is most common immediately after injury. Yeates and Taylor (2005) found that 40% of patients presented with a loss of consciousness, 76% with headache, 44% with vomiting, 41% with nausea, 32% with posttraumatic amnesia, 26% with dizziness, 12% with double or blurred vision, 10% with disorientation, and 2% with transient neurological deficits. While this appears to be the most common cluster of acute symptoms, patients may experience some or none of these.

Within the first month after the injury a number of differences become apparent between children who have experienced mTBI and those who have not.  For example, mTBI group members in one study produced significantly lower scores on response speed tests one week post-injury than did members of the control group (Gagnon, Swaine, Friedman, & Forget, 2004). Children with mTBI also appear to suffer from significantly more memory problems than their uninjured counterparts and performed more poorly on test of concentration (Krivitzky, 2011). Surprisingly, the mTBI groups did not show measurable immediate (or long term) differences in academic performance or cognitive evaluations (McKinlay, Dalrymple-Alford, Norwood, & Fergusson, 2002).

At six and twelve months post-injury, additional differences emerge between groups. The mTBI group had worse performance on a limited time test, visual closure scores, in which children were asked to locate hidden objects within a picture. The mTBI group children were significantly more likely to have sustained another mTBI within the first six months after their initial injury (Wrightson, McGinn, & Gronwall, 1995).

The same study showed that mTBI children also demonstrated lower reading comprehension scores.  Dennis and Barnes (2001) conducted a study suggesting that children with a history of mTBI demonstrated poorer language comprehension than their non-injured peers, specifically on tasks of ironic criticism, deceptive praise, and speech acts.

Immediate Recovery

Research shows that children who sustain mTBI often recover naturally, with the majority of their symptoms normally resolving two to three months post-injury (Carroll et al., 2004; Kirkwood et al., 2008). Some of these children, however, still experience ongoing physical, cognitive, or behavioral problems after the first three-month period following injury (Cook et al., 2006; Ponsford et al., 2001). These symptoms include, but are not limited to, headaches, fatigue, memory impairments, attention difficulties, anxiety, hyperactivity, and conduct disorder (McKinlay et al., 2002; Ponsford et al., 2001). Overall, a child who experiences mTBI has a positive prognosis for complete recovery, notwithstanding the immediate presenting challenges (Carroll et al., 2004).

Despite research demonstrating the resilience of children diagnosed with mTBI, there is evidence that points to significant difficulties in psychosocial and cognitive functioning. These studies tend to show that children experience physical challenges, cognitive deficits, or ongoing emotional and behavioral problem after sustaining mTBI, although the sample size of some of the studies is limited (Cook et al., 2006; Ponsford et al., 2001).

One study found that children who sustain mTBI under the age of five were particularly likely to show signs of hyperactivity/inattention and conduct disorder post-injury in their early teens (McKinlay et al., 2002). Luis and Mittenberg (2002) determined that children who sustained mTBI showed new mood disorders, and are at an increased risk for psychiatric disturbance.

Thus, while the immediate and longer-lasting effects of mTBI can be severe and debilitating, research indicates that many children who suffer mTBI recover naturally, and many others can eventually regain abilities, with little or no long-term loss of functionality. In addition, as discussed below, the affected areas can be targeted with a variety of treatments to reduce the overall residual impact of mTBI.

Treatment

It is important to remember that, particularly with young patients, all clinical care must be individualized.  This includes taking into account each child’s past and current developmental level and unique circumstances, which include family and community support (Kirkwood et al., 2008).  The treatment of mTBI in children cuts across multiple environments of functioning, such as the individual, family, school, and athletics. Because of the scope of the life domains potentially impacted by mTBI, children who require rehabilitation typically work with treatment teams composed of numerous professionals (Hawley et al., 2004).

The initial management of a pediatric patient with a diagnosis of mTBI requires complete physical and cognitive rest, to allow recovery (Kirkwood et al., 2008). This often requires that the child remain in bed and refrain from engaging in activities such as school or intensive family obligations.  A child should not return to strenuous activity, such as athletics, until all symptoms have resolved (Carroll et al., 2004).

When rehabilitation is needed, it is important for the child’s caregiver to be involved in the rehabilitation processes, because the child patient is often not able to provide all the necessary information about pre-injury state.  Caregivers are able to make observations and reports that the child would not be able to otherwise handle, such as behavior or symptom monitoring (Kirkwood et al., 2008).  Collateral information can come not only from caregivers, but from schools or other social outlets and groups.

It is also important that the caregiver be present in the event that an emergency or unusual symptom emerged after the child returns home.  For this reason, psychoeducation of child patients and their caregivers is highly important in the treatment and rehabilitation of mTBI (Hawley et al., 2004).

Patients and caregivers of younger children need encouragement that the symptoms are likely temporary, as the developing brain will accommodate damage through the wonder of brain plasticity (Anderson, Catroppa, Morse, Haritou, & Rosenfeld, 2005). This ability is particularly true in cases of mTBI, where the cognitive load taken on by healthy brain tissue is much less than that required with a severe injury.  This means there is a higher likelihood that another region of the brain will participate in the process impacted by the injury, which will in turn increase functionality and reduce the patient’s symptoms (Anderson et al., 2005; Kirkwood et al., 2008).

Because of this natural recovery, it is important to assess the cause of persistent symptoms. If a child is still experiencing mTBI symptoms after one to two weeks, an evaluation is likely in order to identify reasons for the continued problems and aid in the formation of an adjusted clinical plan (Kirkwood et al., 2008). Any evaluation done in this regard must carefully and precisely define the extent of the continuing injury and rule out more significant neurological injury or medical concern, such as an undiagnosed subdural hematoma (Yue et al., 2013).

If there is no underlying medical condition, psychoeducation should be employed to be sure that the patient’s expectations for recovery are realistic (Hawley et al., 2004).  It is also imperative to assess the patient’s activity level and restrict such activity if the level is too high for the patient’s condition (Kirkwood et al., 2008). It is necessary that patients and caregivers know that, even when initial recovery is accomplished more slowly, there is still a high chance of full recovery (McKinlay et al., 2002). In such cases, a primary concern is reducing the occurrence of a second injury, particularly prior to full recovery (Bazarian et al., 2005).

Future Research

As additional research is done in this area, it would be beneficial to focus on the subjective experience of mTBI in children and their caregivers.  It would be interesting to know if children who experience mTBI and their families agree with the research suggesting few long-term consequence of mTBI for many child patients. There has been limited focus on the reported quality of life of clients who have sustained TBI, although much of this research involves moderate to severe TBI (Emanualson, Andersson Holmkvist, Bjorklund, & Ståringlhammar, 2003).  Meta-analysis on the limited work done demonstrates mixed results, and is itself limited by the lack of tight controls and small samples sizes in the studies included in the analysis (Petchprapai, & Winkelman, 2007).

Recent research has also identified the potential for olfactory dysfunction in pediatric clients with these types of injuries. While the primary focus of such studies has been on TBI in general, some evidence suggests that a subset of mTBI patients may experience this symptom, as well (Bakker, Catroppa, & Anderson, 2014). Additional work should be done on the extent and frequency of limited or persistent olfactory dysfunction in pediatric mTBI patients in order to determine the impact of this issue on the population.

Work is also being done on potential risk factors associated with poor long-term functioning after pediatric mTBI (Zonfrillo et al., 2014). External factors that appear to impact posttrauma functioning include less parental education, low household income, and Medicaid insurance. Other factors likely will be identified through future work.  It will be important to determine the extent of the influence of these factors, as the findings so far seem to indicate that youth who are socioeconomically disadvantaged should receive additional intervention to mitigate the effects of mTBI.

One of the potential intervention methods requiring more study is the use of telehealth interventions. These interventions can be cost-effective ways for children’s caregivers to gain access to needed medical or therapeutic support when financial or time constraints limit a family’s access to care (Woods et al., 2014). This method includes a manualized treatment program for caregivers and others involved in the child’s recovery, along with available telephonic support from professionals.  Pilot research has shown this program to be helpful in the management of mTBI care, although additional work must be done to confirm these findings (Woods et al., 2014).

Conclusion

The sheer number of children each year who experience mTBI is cause enough to examine the repercussions of these types of injuries in this population.  Increased diagnostic accuracy and more standardized definitions make this increasingly realistic.  While many injuries remaining undiagnosed, those that are reported have given a broad picture of what is involved in common pediatric mTBI.

When evaluation shows that the injury sustained is mTBI, service providers and families can draw on a readily-available body of research, treatment options, and resources. While work is still being done to expand the information available and control for some of the limitations of mTBI studies, the physical, cognitive and behavioral consequences of such an injury are well documented. It is also well documented that most occurrences of mTBI resolve naturally, although there is a subset of the injured who do require additional support.  

When managed with appropriate supervision and education, even more complex forms of these injuries may resolve in time. Future research in this area will add to the body of knowledge available to aid in the treatment and recovery of all types of TBI.