Intellectual outcome from preschool traumatic brain injury: a 5-year prospective, longitudinal study

Traumatic brain injury (TBI) is a common, acquired disability that may be used as a model to understand the impact of early brain injury on brain structure and function. To date, few studies have followed very young children over time after insult.

To plot recovery and outcome of intellectual ability after early TBI over the 5 years after injury, and to identify predictors of outcome including injury, sociodemographic and preinjury characteristics, and acute functional recovery.

Children aged between 2 and 7 years who were diagnosed with TBI (N = 54) were consecutively recruited on admission to the Royal Children's Hospital, Victoria, Australia, to participate in a prospective, longitudinal study. Our study had a between-factor design that used injury severity as the independent variable. The participants were categorized into groups according to injury severity (mild, moderate, or severe), and were compared with healthy control participants (n = 16) at the acute time point, and at 12 months, 30 months, and 5 years after injury. Intellectual measures, including verbal and nonverbal skills, attention, and processing speed, were administered.

Children with severe injuries demonstrated slower recovery and poorer cognitive outcomes up to 5 years after injury than did those who were observed for less severe injuries. Recovery trajectories were associated with injury severity over the first 30 months after injury, with the greatest deterioration in function observed for more severe injuries. From 30 months to 5 years after injury, progress was stable. Only injury severity (as determined by the Glasgow Coma Scale score) and acute cognitive performance were strong predictors of 5-year outcomes.

This study has confirmed the high risk of persisting and global deficits associated with severe brain insult in early childhood. Contrary to previous speculation about "growing into deficits," children with severe brain insults have more protracted recovery periods but do not continue to lose ground compared with their peers. By 30 months after insult, recovery seems to stabilize and children begin to make appropriate developmental gains.