Because young children are physically, cognitively and emotionally very different from adults, a different set of tools needs to be developed and used for the diagnosis, recovery-assessment and management of their concussions, recommends a new study.
Given the importance of school, the "primary endpoint" should be "return to learn, not return to play," say the authors of a literature review published in the British Journal of Medicine.
Reviewing studies on concussion assessment on the sports sideline and during recovery, especially for the age group 5-15 years, and the management of concusssion in children and adolescents, the authors, Australian Gavin Davis and Canadian Laura Purcell, report finding:
- no child-specific sideline assessment tools: while there are "many and varied tests" available for the sideline assessment of concussions in adults, none have been specifically developed for children, they found. Of the adult tests which have been considered for use in children, including the Standardized Assessment of Concussion (SAC) and SCAT2, none have been adequately evaluated for use on the sideline with children, and "none has sufficient reliability and validity data to establish the tool as reliable and valid sideline assessment tool in children."
- no post-concussion symptom scales validated in children: Symptom evaluation "remains as a key element of concussion assessment, and is very important in the diagnosis of concussion, monitoring recovery and return-to-play decisionmaking," Davis and Purcell write. Many symptom scales developed for use in adults have been reviewed for use in mTBI (mild traumatic brain injury),[2,3] some have been tested in children to assist in concussion diagnosis, as markers for persistence of symptoms, or to monitor recovery, but none, they said, have been used and validated in children in each stage of concussion, from sideline through recovery. [Note: The study does not mention the child-specific symptom-scale developed as part of the Child-SCAT3 issued in conjunction with the 4th International Conference on Concussion in Sport. ]
- no tools for monitoring recovery from concussion in children validated. The authors noted the existence of tools with potential use to monitor recovery from concussion in children, including child- and parent-reported symptom scales and child assessments, but found no published data on serial testing, and, in particular, pointed to the absence of any studies of clinical depression in concussed children, which can be misdiagnosed as persistent post-concussion symptoms in adults, research which is especially needed because depression in children may be "exacerbated in the dysfunctional family, where parent-reported symptoms may be less reliable or differ markedly from the child-reported symptoms."
- balance and reaction time tests not tested in children: Davis and Purcell report a lack of studies validating the use in younger athletes of the Balance Error Scoring System (BESS), a test of balance widely used in diagnosing older athletes, but expressed concern that reliability studies using the BESS in children aged 9-14 years had revealed a significant practice effect, and variability in results between the different leg stances. Measuring simple reaction time has shown promise as a tool for assessment of physical and cognitive function, they said, with the added advantage that such tests can be performed on the sideline or in a clinic without a computer. They cite a recent study of concussed collegiate and high school athletes which report promising results in distinguishing between concussed and non-concussed athletes using nothing more than a weighted stick or lined ruler dropped by the examiner and caught by the athlete to calculate reaction time; but said Its utility for children has yet to be demonstrated.
- concussion management: while acknowledging a dearth of studies evaluating the management of concussion in younger age groups, Davis and Purcell found that the expert consensus continues to be that the "keystone of concussion management in all age groups, including children and adolescents, is REST, both physical and cognitive." [capital letters in original], with restrictions on physical activity maintained until the child/adolescent is asymptomatic at rest, at which point they can progress through a medically-supervised return-to-play protocol (which, they emphasized, should be "cautious and individualized" in pediatric patients).
- Davis and Purcell said that there were no clear guidelines to guide the return to school for youths who have sustained a concussion, although they recognized that this was an area of increasing interest. [In fact, the American Academy of Pediatrics issued return to learn guidelines after the study was finalized for publication].
- Given the significant amount of time children and adolescents spend in the classroom, and how vital school attendance was for them to learn and socialize, they said that "full return to school should be a priority following a concussion," and emphasized that "return to learn should precede return to play." [emphasis in original]
- A concussed student, they said, does not have to have total resolution of their symptoms before resuming school attendance, calling for a "stepwise approach" of increasing cognitive activity, similar to the stepwise return-to-play protocol, to allow students to return to the academic setting without exacerbating their symptoms, recognizing that a temporary absence from school to provide cognitive rest to allow symptoms to abate might be necessary, and recommending a gradual return to a full academic day, which might mean attending for only a half a day or for only certain classes.
The study makes a number of recommendations, advocating for:
- development of specialized tests which take into account the developmental changes (language, reading, cognitive, and physical) a child undergoes between ages 5 and 15, including:
- symptom scales which include language understood by younger children and symptoms with which they are familiar (this is the approach taken in the Child-SCAT3), and parent or teacher reports integrated into recovery as well as return-to-learn and return-to-play decision-making; and
- developmentally appropriate cognitive tests with demonstrated validity in measuring change in cognition and recovery. In testing the validity of such tests, they emphasize that it will be important to ensure that the full complement of tests fall within the concentration span of both the normal and concussed child, as validating isolated elements of an overall test separately might not be representative of the true clinical environment, where tests are performed in one session;
- assuming a "primary endpoint" of return to learn, not return to play, with the return to learn following a stepwise increase in cognitive activities (see discussion above); and
- utilizing of a cooperative, team approach between child, parents, teachers, and medical staff in order to manage the negative effects of concussion on the child's ability to learn in school, and using a multi-disciplinary team including the student, family/guardians/caregivers, the coach and athletic trainers, the physician, teachers, school principal and other school personnel as available (counselors, nurses, ATs, and neuropsychologists), ensuring communication among team members, as well as education of all members, so that all are aware of the student's progress and the accommodations necessary to facilitate the student's recovery.
Concussions in children are different
Among the reasons the study authors identified as reasons why a concussion in a child is different from that in an adult are:
- physiological differences: the young, immature brain, with decreased myelination, is developing rapidly during the early childhood years; the young child's skull is relatively thin; and the neck, shoulder and back muscles supporting the preadolescent head are poorly developed.
- the impact forces necessary to cause concussion are different: Animal studies suggest that the impact force required to produce concussion may be more than twice as great in children than adults (10,000 rads/s2 versus 4,500 rads/s2 of rotational acceleration (the kind of force that experts believe may be the most damaging to the brain), that the poorly developed cervical musculature, in combination with the increased head-to-neck ratio in children, results in greater injury to the child's brain, than the adult's, for the same impact force.
- recovery times are generally longer: On average, concussed high school athletes take twice as long to recover (10-14 days) than college and professional athetes (3-7 days).[8,9] and preadolescent children may take even longer to recover. The reason, experts suspect, may be due to two factors:
- greater brain pasticity: the neural connections in a child's developing brain are constantly changing and reorganizing as a child learns new things (such as how to play a musical instrument) or memorizes new information, a process called neuroplasticity. The downside to this process is that it also makes the young brain more vulnerable to the effects of trauma;
- less developed brain myelination: myelination is the process by which a fatty layer, called myelin, accumulates around nerve cells (neurons) in the brain.
- Myelination is less developed in areas of the pre-adolescent brain, particularly the frontal lobe that begins just behind the forehead, often affected by concussion, such as one caused by a blow to the forehead or top of the head, as in helmet-to-helmet contact in football.
- Myelination of the frontal lobe aids cognitive development in older children ("tweens") and adolescents. In particular, it enables them to have better "executive functioning," which includes planning, reasoning and decision making skills. It also helps tweens and adolescents inhibit their impulses more efficiently and to demonstrate greater self-discipline.
- Because the frontal areas of the brain believed to play a role in the ability to focus attention on relevant stimuli while filtering out extraneous information are among the last areas of the brain to develop, the authors of two recent studies speculate that this region of the adolescent brain may be more susceptible to concussion and that deficits in executive function from concussion may last longer in this population than older age groups.[10,11]
- greater effect on school and learning. Concussion may significantly impact the child's ability to return to school because of the neurocognitive deficits it causes, such as slowed information processing, difficulty forming new memory (e.g. anterograde amnesia) and inabilty to concentrate.
- potential for more long-term effects: While the long-term effects of a single or multiple concussion are not yet known, experts believe that a child exposed to a first concussion at a younger age will have a larger "window of opportunity" for further concussive injuries during the formative years than a person who does not sustain a first concussion until college, placing the child at greater risk of long-term brain injury.
- unique risk of Second Impact Syndrome: The condition commonly referred to as Second Impact Syndrome (a rapid onset, post-concussion swelling of the brain) is known to occur only in young children and adolescents, and does not occur in the adult population.