Traumatic Brain Injury (TBI) is a condition that is well understood in its causes and the consequences to the physical brain itself, but, the implication of childhood TBI on the neurological development of the child, (particularly the development of cognitive and functional skills) is an area that requires much further investigation according to researchers from Australia (Melbourne, Victoria)(1).
Many parents, teachers and professionals dismiss the ramifications of an early childhood TBI in the later neurological development of a child. Childhood TBI is the most common cause of disrupted neurological development. Between 219 and 345 in a 100,000 children experience a TBI annually (2,3). 1 in 30 newborns will suffer a TBI by the age of 16 (2). Children under the age of three have double the risk of a TBI than any other age group throughout childhood (3). Children in this category suffer from a high proportion of falls which result in moderate to severe TBI. However, those who experience TBI as the result of motor vehicle crashes and pedestrian vehicular injuries suffer the most severe axonal injury due to acceleration and deceleration forces on the brain (4). There are three reasons for this:
1. A thin and pliable skull is at increased risk of diffused injury (5,6)
2. Increased susceptibility to neuronal shearing and rotational forces because the head is much larger than the body with weak neck muscles. (6,7)
3. Blood vessels are highly elastic(6)
This leads to more significant brain damage (mass lesion, subdural haemotoma, tears in the white matter of the frontal lobes) after TBI in children under the age of three than in older children.
It is a common misconception that the brain rewires itself after a TBI and that nothing is really affected some two, five or ten years later. This misconception is all the more alarming because 1 in 3 children who experience a TBI will endure permanent brain damage(2).
Researchers in Melbourne have found evidence that challenges this myth that young children are more resilient to TBI(1). Their longitudinal study selected patients from the Royal Melbourne Hospital during 1993 to 1997 and showed that young children who suffered a severe TBI before the age of three show lower intelligence (1-2 Standard Deviations lower than the mean IQ for their age) than their healthy counterparts ten years post injury (1). This suggests global and persisting intellectual deficits in children who have suffered a serious TBI in childhood.
Furthermore, a child’s preinjury social functioning and environmental factors such as socio-economic status (SES) were good predictors of their outcome in 10 years post injury(1). SES has been closely related to early TBI not only in its relationship with the recovery itself, but also as a causative factor of the initial TBI (3). In fact in injuries on children less than three years of age, the SES of the family is the strongest predictor of intellectual functioning, when the children were tested at four and six years old(13 as cited in 8). However, this study further illustrated that regardless of the severity of the TBI, recovery rate plateaus between five and ten years showing that there is no significant relationship between the rate of recovery and the severity of the injury (1).
Furthermore, preinjury adaptive function (social function) was predictive of 10 year adaptive abilities with social and behavioural outcomes being predicted by family function (1). Since children at this age are developing neurobehavioural skills, they have an increased risk of disrupted development and clinical reports suggest residual problems in cognition, attention, executive function and memory (9, 10). These children therefore may have difficulty or fail to acquire adaptive behaviors, academic skills and appropriate social behaviors and skills (11, 12). Other predictors of long-term behavioural, social and intellectual development of the individual who experiences an early childhood TBI include the parental mental health as well as family and parental function (8).
In addition to intellectual deficits, social deficits are also common after early childhood TBI. In another study, it was found that children who suffer from a TBI before the age of four experience greater difficulties socialising than their healthy counterparts (13).
These findings are inconsistent with the argument that young children grow into deficits throughout childhood (4,14,15) and instead appears to indicate a consistent lag in comparison to healthy children. Persistent intellectual impairment is more likely to arise from TBI involving high levels of acceleration and deceleration forces to the brain (motor vehicles, motor bikes and pedestrian automobile related injuries) which produce severe white matter injury that is diffuse or multi-focal.
The management of TBI is multimodal and involves diet and nutrition; motor coordination; memory retraining; neurofeedback and improving auditory processing skills. For more information on the management of TBI, please see the articles on Neurofeedback and TBI. For initial consultations and assessments, please contact the office during business hours to make an appointment on (02) 9637 9998.
References:
1. Anderson V, Godfrey C, Rosenfeld JV, Catroppa C. Predictors of Cognitive Function and Recovery 10 Years After Traumatic Brain Injury in Young Children. Pediatrics. 2012;129:254-261.
2. Kraus JF. Epidemiological features of brain injury in children, In: Broman SH, Michel ME, eds. Traumatic Head Injury in Children. New York, NY: Oxford University Press; 1995: 117 – 146.
3. Crowe L, Babl F, Anderson V, Catroppa C. The epidemiology of paediatric head injuries: data from a referral centre in Victoria, Australia. J Paediatric Child Health. 2009; 45(6); 346-350.
4. Levin HS. Long-term intellectual Outcome of Traumatic Brain Injury in Children: Limits to Neuroplasticity of the Young Brain? Pediatrics 2012;129(2):494-495.
5. Hanh YS, Chyung C, Barthel MJ, Bailes J, Flannery AM, McLone DG. Head Injuries in children under 36 months of age. Demography and outcome. Childs Nerv Syst. 1988;4(1): 34-40.
6. Case ME. Forensic Pathology of child brain trauma. Brain Pathol. 2008;18(4):562-564.
7.Margulies SS, Thibault KL. Infant Skull and suture properties: measurements and implications for mechanisms of pediatric brain injury. J Biomech Eng. 2000;122(4):364-371.
8. Crowe LM, Catroppa C, Babl FE, Anderson V. Intellectual, Behavioral and Social Outcomes of Accidental Traumatic Brain Injury in Early Childhood. Pediatrics2012;129(2):262-268.
9. Anderson V, Catroppa C, Morse S, Haritou F, Rosenfeld JV. Intellectual outcome from preschool traumatic brain injury: a 5-year prospective, longitudinal study. Pediatrics. 2009; 124(6).
10. Jaffe KM, Fay GC, Polissar NL, et al. Severity of pediatric traumatic brain injury and neurobehavioural recovery at one year–a cohort study. Arch Phys Med Rehabil. 1993;74(6):587-595.
11. Benz B, Ritz A, Kiesow S. Influence of age-related factors in long-term outcome after traumatic brain Injury (TBI) in children: a review of recent literatire and some preliminary findings. Restor Neurol Neurosci. 1999;14(2-3): 135-141.
12. McKinlay A, Dalrymple-Alford JC, Horwood LJ, Fergusson DM. Long term psychosocial outcomes after mild head injury in early childhood. J Neurol Neurosurg Psychiatry. 2002; 73(3):281-288.
13. Sonnerberg LK, Dupuis A, Rumney PG. Pre-school traumatic brain injury and its impact on social development at 8 years of age. Brain Inj. 2010;24(7-8):1003-1007.
14. Giza CC, Prins ML. Is being plastic fantastic? Mechanisms of altered plasticity after developmental traumatic brain injury. Dev Neurosci. 2006;28(4-5):364-379.
15.Dennis M. Language and the young damaged brain. In: Boll T, Bryant BK, eds. Clinical Neuropsychology and Brain Function: Research, Measurement and Practice. Washington, DC: American Psychological Association; 1989:85-124.
