Response Inhibition After Traumatic Brain Injury (TBI) in Children: Impairment and Recovery

Children who experience traumatic brain injury (TBI) often show cognitive impairments postinjury, some of which recover over time. We examined the recovery of motor response inhibition immediately following TBI and over 2 years. We assessed the role of injury severity, age at injury, and lesion characteristics on initial impairment and recovery while considering the role of pre-injury psychiatric disorder. Participants were 136 children with TBI aged 5–16 years. Latency of motor response inhibition was measured with the stop-signal task within 1 month of the injury and again at 3, 6, 12, and 24 months. The performance of the TBI participants at each measurement occasion was standardized with 117 children of similar age, but without injury. Residualized latency scores were calculated. Growth curve analyses showed an initial impairment in response inhibition and improvement over the 2 years following injury. Younger TBI patients were initially more impaired although they exhibited greater recovery of response inhibition than did older TBI patients. Longer duration of coma, but not reactivity of pupils or Glasgow Coma Scale score, predicted initial deficit. Lesion characteristics or pre-injury attention deficit hyperactivity disorder did not predict initial impairment or recovery. Replication with longitudinal testing of a comparison group of children sustaining extracranial injury is necessary to confirm our findings.     

Attention Deficit Hyperactivity Disorder Symptoms and Response Inhibition After Closed Head Injury in Children: Do Preinjury Behavior and Injury Severity Predict Outcome?

We examined the effect of closed head injury (CHI) on the development of symptoms of secondary attention deficit hyperactivity disorder (SADHD), emotional disturbance, and impaired response inhibition. We also investigated the relation of developmental and recovery variables to SADHD symptoms and inhibition. Participants were 200 children aged 5-17 years, 137 children who had CHI, and 63 children with no history of CHI served as controls. We assessed preinjury behavior problems, head injury variables (severity, age at time of injury, time since injury), postinjury SADHD, and anxiety symptoms at least 2 years following the head injury. Response inhibition was measured with the stop-signal task. CHI predicted the development of SADHD symptoms and anxiety with more severe injury predicting more severe outcomes. Only the combination of severe CHI and a high level of SADHD symptoms predicted poor response inhibition. Postinjury anxiety was not associated with poor inhibition. The consequences of CHI did not vary with age at injury or time since injury, but poorer outcome was predicted by preinjury behavior problems. CHI in children leads to SADHD symptoms and anxiety even after taking preinjury disturbance into account. Poor response inhibition is a consequence of CHI but only when the CHI is severe and the child manifests high levels of SADHD symptoms.     

Attention Deficit Hyperactivity Disorder Symptoms and Response Inhibition After Closed Head Injury in Children: Do Preinjury Behavior and Injury Severity Predict Outcome?

We examined the effect of closed head injury (CHI) on the development of symptoms of secondary attention deficit hyperactivity disorder (SADHD), emotional disturbance, and impaired response inhibition. We also investigated the relation of developmental and recovery variables to SADHD symptoms and inhibition. Participants were 200 children aged 5-17 years, 137 children who had CHI, and 63 children with no history of CHI served as controls. We assessed preinjury behavior problems, head injury variables (severity, age at time of injury, time since injury), postinjury SADHD, and anxiety symptoms at least 2 years following the head injury. Response inhibition was measured with the stop-signal task. CHI predicted the development of SADHD symptoms and anxiety with more severe injury predicting more severe outcomes. Only the combination of severe CHI and a high level of SADHD symptoms predicted poor response inhibition. Postinjury anxiety was not associated with poor inhibition. The consequences of CHI did not vary with age at injury or time since injury, but poorer outcome was predicted by preinjury behavior problems. CHI in children leads to SADHD symptoms and anxiety even after taking preinjury disturbance into account. Poor response inhibition is a consequence of CHI but only when the CHI is severe and the child manifests high levels of SADHD symptoms.     

Attention deficit hyperactivity disorder symptoms and response inhibition after closed head injury in children: do preinjury behavior and injury severity predict outcome?

We examined the effect of closed head injury (CHI) on the development of symptoms of secondary attention deficit hyperactivity disorder (SADHD), emotional disturbance, and impaired response inhibition. We also investigated the relation of developmental and recovery variables to SADHD symptoms and inhibition. Participants were 200 children aged 5-17 years, 137 children who had CHI, and 63 children with no history of CHI served as controls. We assessed preinjury behavior problems, head injury variables (severity, age at time of injury, time since injury), postinjury SADHD, and anxiety symptoms at least 2 years following the head injury. Response inhibition was measured with the stop-signal task. CHI predicted the development of SADHD symptoms and anxiety with more severe injury predicting more severe outcomes. Only the combination of severe CHI and a high level of SADHD symptoms predicted poor response inhibition. Postinjury anxiety was not associated with poor inhibition. The consequences of CHI did not vary with age at injury or time since injury, but poorer outcome was predicted by preinjury behavior problems. CHI in children leads to SADHD symptoms and anxiety even after taking preinjury disturbance into account. Poor response inhibition is a consequence of CHI but only when the CHI is severe and the child manifests high levels of SADHD symptoms.     

Impact of posttraumatic stress disorder and injury severity on recovery in children with traumatic brain injury

The adverse impact on recovery of posttraumatic stress disorder (PTSD) in mild traumatic brain injury (TBI) has been demonstrated in returned veterans. The study assessed this effect in children's health outcomes following TBI and extended previous work by including a full range of TBI severity, and improved assessment of PTSD within a longitudinal design. There were 205 children and adolescents (6 to 15 years of age) who experienced a TBI that were assessed at 2, 3, 6, 12, and 18 months following the TBI. Severity of TBI was classified as mild, moderate, or severe. After controlling for the impact of the severity of TBI, premorbid behavioral and emotional problems and executive function, children with TBI and PTSD did not experience as much psychosocial recovery as those without PTSD. Furthermore the level of psychosocial function was no better than that experienced by children with a severe TBI. In contrast, severe TBI was predictive of a poorer physical recovery in the first 6 months, after which recovery was equivalent across all severity levels.     

Understanding predictors of functional recovery and outcome 30 months following early childhood head injury

Much is known about outcome following traumatic brain injury (TBI) in school-age children; however, recovery in early childhood is less well understood. Some argue that such injuries should lead to good outcome, because of the plasticity of the developing brain. Other purport that the young brain is vulnerable, with injury likely to result in a substantial impairment (H. G. Taylor & J. Alden, 1997). The aim of this study was to examine outcomes following TBI during early childhood, to plot recovery over the 30 months postinjury, and to identify predictors of outcome. The study compared 3 groups of children sustaining mild, moderate, and severe TBI, ages 2.0 to 6.11 years at injury, with healthy controls. Groups were comparable for preinjury adaptive and behavioral function, psychosocial characteristics, age, and gender. Results suggested a strong association between injury severity and outcomes across all domains. Further, 30-month outcome was predicted by injury severity, family factors, and preinjury levels of child function. In conclusion, children with more severe injuries and lower preinjury adaptive abilities, and whose families are coping poorly, are at greatest risk of long-term impairment in day-to-day skills, even several years postinjury.     

Influences on first-year recovery from traumatic brain injury in children

This study examined recovery over the first year following traumatic brain injury (TBI) in children 6-12 years of age. Forty-two children with severe TBI and 52 with moderate TBI were compared to 58 children with orthopedic injuries. The children and their families were evaluated at a baseline assessment and at 6- and 12-month follow-ups. Findings documented cognitive, achievement, and behavioral sequelae of TBI, with only limited evidence for recovery over the first year postinjury. Outcomes were predicted by preinjury factors, TBI severity, and measures of the postinjury family environment. Some of the sequelae of severe TBI were more marked in the context of higher compared with lower levels of family burden or dysfunction. The findings confirm the need to consider environmental contributions to outcomes of TBI in children.     

Short-term neuropsychological outcome following uncomplicated mild TBI: effects of day-of-injury intoxication and pre-injury alcohol abuse

Research suggests that individuals who are intoxicated at the time of traumatic brain injury (TBI) have worse cognitive outcome compared with those who are sober. Worse outcome in patients with day-of-injury intoxication might (a) be related to the increased magnitude of brain injury resulting from a variety of negative responses not present following TBI in nonintoxicated individuals, or (b) reflect the effect of pre-injury alcohol abuse that is prevalent in individuals intoxicated at the time of injury. Most studies in this area have focused on patients with moderate to severe TBIs, and on medium- to long-term neuropsychological outcome. The purpose of this study was to examine the relative contributions of day-of-injury intoxication versus pre-injury alcohol abuse on short-term cognitive recovery following mild TBI. Participants were 169 patients with uncomplicated mild TBIs who were assessed on 13 cognitive measures within 7 days postinjury. The prevalence of intoxication at the time of injury was 54.4%. The prevalence of possible pre-injury alcohol abuse was 46.2%. Overall, the results suggest that pre-injury alcohol abuse, compared with day-of-injury alcohol intoxication, had the most influence on short-term neuropsychological outcome from uncomplicated mild TBI. However, the influence of pre-injury alcohol abuse was considered small at best.     

Brief report: parental report of sleep behaviors following moderate or severe pediatric traumatic brain injury

OBJECTIVE: Determine the effect of moderate and severe traumatic brain injuries (TBI) on the sleep of school-aged children. METHODS: A concurrent cohort-prospective design compared children aged 6-12 years who sustained moderate TBI (baseline n = 56), severe TBI (n = 53), or only orthopedic injuries (n = 80). Retrospective parental report of pre-injury sleep was collected about 3 weeks post-injury. Post-injury assessments occurred prospectively a mean of 6, 12, and 48 months later. RESULTS: Growth curve analyses compared the groups over time. The moderate TBI group had worse pre-injury sleep than the other groups. The moderate TBI and orthopedic injury groups displayed a small decline in sleep problems from pre- to post-injury. Children with severe TBI displayed increased post-injury sleep problems. CONCLUSIONS: Children who sustain severe TBI are at elevated risk for post-injury sleep problems. Because sleep problems may result in daytime impairments and family distress, additional clinical and research attention is warranted.     

Modeling of Longitudinal Academic Achievement Scores After Pediatric Traumatic Brain Injury

In a prospective longitudinal study, academic achievement scores were obtained from youth 5 to 15 years of age who sustained mild-moderate (n = 34) or severe (n = 43) traumatic brain injuries (TBI). Achievement scores were collected from baseline to 5 years following TBI and were subjected to individual growth curve analysis. The models fitted age at injury, years since injury, duration of impaired consciousness, and interaction effects to Reading Decoding, Reading Comprehension, Spelling, and Arithmetic standard scores. Although scores improved significantly over the follow-up relative to normative data from the standardization sample of the tests, children with severe TBI showed persistent deficits on all achievement scores in comparison to children with mild-moderate TBI. Interactions of the slope and age parameters for the Arithmetic and Reading Decoding scores indicated greater increases over time in achievement scores of the children injured at an older age, but deceleration in growth curves for the younger children with both mild-moderate and severe TBI. These results are compatible with the hypothesis that early brain injuries disrupt the acquisition of some academic skills. Hierarchical regression models revealed that indexes of academic achievement obtained 2 years following TBI had weak relations with the duration of impaired consciousness and socioeconomic status. In contrast, concurrent cognitive variables such as phonological processing and verbal memory accounted for more variability in academic scores. Given the significant and persistent decrement in basic academic skills in youth with severe TBI, it is clear that head-injured youth require intensive, long-term remediation and intervention not only of the academic skills themselves, but also of those cognitive abilities that support the development and maintenance of reading and math.     

IQ loss and emotional dysfunctions after mild head injury incurred in a motor vehicle accident

Intelligence and personality dysfunctions after minor traumatic brain injury (TBI) (whiplash; slight head impact) incurred in a motor vehicle accident (MVA) were studied in adults after an average interval of 20 months. There was a mean loss of 14 points of Full Scale IQ from estimated pre-injury baseline IQ determined from the standardization group (WAIS-R) without evidence for recovery. Personality dysfunctions included cerebral personality disorder, psychiatric diagnosis (30 of 33 patients), post-traumatic stress disorders, persistent altered consciousness, and psychodynamic reactions to impairment. Cognitive loss is caused by interaction of brain injury with distractions such as pain and emotional distress. Unreported head impact and altered consciousness at the time of accident contribute to the underestimation of brain trauma after minor TBI. © 1996 John Wiley & Sons, Inc.     

Modeling of longitudinal academic achievement scores after pediatric traumatic brain injury

In a prospective longitudinal study, academic achievement scores were obtained from youth 5 to 15 years of age who sustained mild-moderate (n = 34) or severe (n = 43) traumatic brain injuries (TBI). Achievement scores were collected from baseline to 5 years following TBI and were subjected to individual growth curve analysis. The models fitted age at injury, years since injury, duration of impaired consciousness, and interaction effects to Reading Decoding, Reading Comprehension, Spelling, and Arithmetic standard scores. Although scores improved significantly over the follow-up relative to normative data from the standardization sample of the tests, children with severe TBI showed persistent deficits on all achievement scores in comparison to children with mild-moderate TBI. Interactions of the slope and age parameters for the Arithmetic and Reading Decoding scores indicated greater increases over time in achievement scores of the children injured at an older age, but deceleration in growth curves for the younger children with both mild-moderate and severe TBI. These results are compatible with the hypothesis that early brain injuries disrupt the acquisition of some academic skills. Hierarchical regression models revealed that indexes of academic achievement obtained 2 years following TBI had weak relations with the duration of impaired consciousness and socioeconomic status. In contrast, concurrent cognitive variables such as phonological processing and verbal memory accounted for more variability in academic scores. Given the significant and persistent decrement in basic academic skills in youth with severe TBI, it is clear that head-injured youth require intensive, long-term remediation and intervention not only of the academic skills themselves, but also of those cognitive abilities that support the development and maintenance of reading and math.     

Modeling of Longitudinal Academic Achievement Scores After Pediatric Traumatic Brain Injury

In a prospective longitudinal study, academic achievement scores were obtained from youth 5 to 15 years of age who sustained mild-moderate (n = 34) or severe (n = 43) traumatic brain injuries (TBI). Achievement scores were collected from baseline to 5 years following TBI and were subjected to individual growth curve analysis. The models fitted age at injury, years since injury, duration of impaired consciousness, and interaction effects to Reading Decoding, Reading Comprehension, Spelling, and Arithmetic standard scores. Although scores improved significantly over the follow-up relative to normative data from the standardization sample of the tests, children with severe TBI showed persistent deficits on all achievement scores in comparison to children with mild-moderate TBI. Interactions of the slope and age parameters for the Arithmetic and Reading Decoding scores indicated greater increases over time in achievement scores of the children injured at an older age, but deceleration in growth curves for the younger children with both mild-moderate and severe TBI. These results are compatible with the hypothesis that early brain injuries disrupt the acquisition of some academic skills. Hierarchical regression models revealed that indexes of academic achievement obtained 2 years following TBI had weak relations with the duration of impaired consciousness and socioeconomic status. In contrast, concurrent cognitive variables such as phonological processing and verbal memory accounted for more variability in academic scores. Given the significant and persistent decrement in basic academic skills in youth with severe TBI, it is clear that head-injured youth require intensive, long-term remediation and intervention not only of the academic skills themselves, but also of those cognitive abilities that support the development and maintenance of reading and math.     

Posttraumatic stress symptoms in children following orthopedic or traumatic brain injury

Examined posttraumatic stress (PTS) symptoms in children following pediatric traumatic brain injury (TBI). Children (ages 6-12) with TBI (n = 81) and orthopedic injury (01; n = 59) were assessed 6 and I2 months postinjury. Parents of children with severe TBI reported higher levels of child PTS symptoms than did parents of children with moderate TBI or 0 1 at the 6- and 12-month follow-ups. Group differences in child-reported PTS symptoms emerged at the 12-month follow-up with higher symptom levels reported by children with severe TBI than by those with moderate TBI or OI. At both follow-ups, rates of clinically significant symptom levels were higher in the severe TBI group than in the moderate TBI or OI groups. The group differences in parent and child reports were significant even after taking ethnicity, social disadvantage, and age at injury into account. Parent and child reports of child PTS symptoms were related to family socioeconomic status. Implications for clinical intervention with children and families following pediatric TBI are discussed.     

Executive Functions Following Traumatic Brain Injury in Young Children: A Preliminary Analysis

To examine executive processes in young children with traumatic brain injury (TBI), we evaluated performance of 44 children who sustained moderate-to-severe TBI prior to age 6 and to 39 comparison children on delayed response (DR), stationary boxes, and spatial reversal (SR) tasks. The tasks have different requirements for holding mental representations in working memory (WM) over a delay, inhibiting prepotent responses, and shifting response set. Age at the time of testing was divided into 10- to 35- and 36- to 85-month ranges. In relation to the community comparison group, children with moderate-to-severe TBI scored significantly lower on indexes of WM/inhibitory control (IC) on DR and stationary boxes tasks. On the latter task, the Age × Group interaction indicated that performance efficiency was significantly reduced in the older children with TBI relative to the older comparison group; performance was similar in younger children irrespective of injury status. The TBI and comparison groups did not differ on the SR task, suggesting that shifting response set was not significantly altered by TBI. In both the TBI and comparison groups, performance improved with age on the DR and stationary boxes tasks. Age at testing was not significantly related to scores on the SR task. The rate of acquisition of working memory (WM) and IC increases steeply during preschool years, but the abilities involved in shifting response set show less increase across age groups (Espy, Kaufmann, & Glisky, 2001; Luciana & Nelson, 1998). The findings of our study are consistent with the rapid development hypothesis, which predicts that skills in a rapid stage of development will be vulnerable to disruption by brain injury.     

Comparison of cognitive impairment associated with major depression following stroke versus traumatic brain injury

Several studies have reported an association between cognitive impairment and major depression following stroke but failed to find a similar association among patients with traumatic brain injury (TBI). This study examined the hypothesis that age differences between stroke and TBI patients would account for the differences in the effect of major depression on cognitive function. We examined subjects' cognitive function using the Mini-Mental State Examination and compared findings among patients with stroke or TBI. Results indicated that stroke patients with major depression (N = 73) were significantly older and more cognitively impaired than similar TBI patients (N = 35), even after matching patients for lesion volume and years of education. After matching for age, however, there was no association of major depression with cognitive impairment in this relatively young stroke population. These findings support the hypothesis that age, presumably related to physiological response to brain injury, accounts for differences in the effect of major depression on cognitive function between stroke and TBI patients.     

Executive functions following traumatic brain injury in young children: a preliminary analysis

To examine executive processes in young children with traumatic brain injury (TBI), we evaluated performance of 44 children who sustained moderate-to-severe TBI prior to age 6 and to 39 comparison children on delayed response (DR), stationary boxes, and spatial reversal (SR) tasks. The tasks have different requirements for holding mental representations in working memory (WM) over a delay, inhibiting prepotent responses, and shifting response set. Age at the time of testing was divided into 10- to 35- and 36- to 85-month ranges. In relation to the community comparison group, children with moderate-to-severe TBI scored significantly lower on indexes of WM/inhibitory control (IC) on DR and stationary boxes tasks. On the latter task, the Age × Group interaction indicated that performance efficiency was significantly reduced in the older children with TBI relative to the older comparison group; performance was similar in younger children irrespective of injury status. The TBI and comparison groups did not differ on the SR task, suggesting that shifting response set was not significantly altered by TBI. In both the TBI and comparison groups, performance improved with age on the DR and stationary boxes tasks. Age at testing was not significantly related to scores on the SR task. The rate of acquisition of working memory (WM) and IC increases steeply during preschool years, but the abilities involved in shifting response set show less increase across age groups (Espy, Kaufmann, & Glisky, 2001; Luciana & Nelson, 1998). The findings of our study are consistent with the rapid development hypothesis, which predicts that skills in a rapid stage of development will be vulnerable to disruption by brain injury.     

Traumatic brain injury in children – clinical implications

Traumatic brain injury (TBI) is the leading cause of death in childhood; however only very few studies focusing on the specific pathophysiology and treatment have been published to date. Head trauma is more likely in young children than in adults given the same deceleration of the body due to their large and heavy heads and weak cervical ligaments and muscles. Resulting brain injury is more severe due to their thin, pliable skulls and the yet unfused sutures. Accordingly, children below the age of 4 years have lower chances of a full recovery after severe TBI, although in general, neurologic recovery after severe brain injury in children is better than in adults. The time course of brain injury can be divided into two steps: primary and secondary injury. Primary brain injury exclusively results from the initial impact. In contrast, adverse physiologic conditions during recovery after head trauma may account for additional brain damage, which is then referred to as secondary brain injury. As primary brain injury can only be influenced by preventive measures, all therapeutic efforts during the post-injury period focus on the reduction of secondary injury to the traumatized brain. Several mechanisms have been identified to be involved in the development of post-traumatic secondary brain injury, which render the rationale for the key treatment strategies. Three evidence based measures are of critical importance to prevent or minimize secondary brain injury: (1) avoid hypoxemia, (2) avoid post-traumatic arterial hypotension, and (3) refer the traumatized child to an experienced trauma team at a center that provides the availability of special equipment, e.g. for surgical procedures and airway management, for this age group. For several other therapeutical means, e.g. hypothermia or specific surgical interventions, clinical evidence to date is insufficient to allow recommendation as rescue treatment for children at risk of severe neurological sequelae following TBI. This review discusses the clinical implication of pathophysiologic mechanisms of TBI in the developing brain according to the recent literature and current guidelines. It follows the clinical approach to a head injured child, that can be divided into three phases, i.e. initial assessment and stabilization, followed by first tier, and if necessary second tier therapeutic interventions to assure adequate oxygenation and perfusion of the brain.     

Attention Deficit Hyperactivity Disorder in Children and Adolescents Following Traumatic Brain Injury

To better characterize pediatric psychopathology after neurological insult, secondary attention deficit hyperactivity disorder (SADHD)-or ADHD that develops after traumatic brain injury (TBI)-and its clinical and neuroimaging correlates were investigated. Outcome data were available for 118 children, ages 5 through 14 at the time of hospitalization following TBI (severe TBI n = 37; mild-moderate TBI n = 57) and orthopedic injury (n = 24). Standardized psychiatric, adaptive functioning, cognitive functioning, family functioning, and family psychiatric history assessments were conducted on all participants. Severity of injury and neuroimaging lesion assessments were conducted on TBI participants only. The diagnosis of SADHD was mutually exclusive with preinjury ADHD, which occurred in 13 of 94 TBI participants and 4 of 24 orthopedic injury participants. SADHD occurred in 13 of 34 eligible participants with severe TBI but resolved in 4 of 13 of these participants. SADHD also occurred in 1 of 8 eligible moderate TBI participants, only in the presence of preinjury ADHD traits and 3 of 39 of eligible mild TBI cases. SADHD occurred in 1 of 20 of eligible participants with orthopedic injury without any brain injury. SADHD was significantly associated with TBI severity recorded by categorical and dimensional measures, intellectual and adaptive functioning deficits, and personality change due to TBI, but not with lesion area or location. These results suggest that SADHD is a clinically important syndrome after severe TBI in children and adolescents.     

Attention Deficit Hyperactivity Disorder in Children and Adolescents Following Traumatic Brain Injury

To better characterize pediatric psychopathology after neurological insult, secondary attention deficit hyperactivity disorder (SADHD)-or ADHD that develops after traumatic brain injury (TBI)-and its clinical and neuroimaging correlates were investigated. Outcome data were available for 118 children, ages 5 through 14 at the time of hospitalization following TBI (severe TBI n = 37; mild-moderate TBI n = 57) and orthopedic injury (n = 24). Standardized psychiatric, adaptive functioning, cognitive functioning, family functioning, and family psychiatric history assessments were conducted on all participants. Severity of injury and neuroimaging lesion assessments were conducted on TBI participants only. The diagnosis of SADHD was mutually exclusive with preinjury ADHD, which occurred in 13 of 94 TBI participants and 4 of 24 orthopedic injury participants. SADHD occurred in 13 of 34 eligible participants with severe TBI but resolved in 4 of 13 of these participants. SADHD also occurred in 1 of 8 eligible moderate TBI participants, only in the presence of preinjury ADHD traits and 3 of 39 of eligible mild TBI cases. SADHD occurred in 1 of 20 of eligible participants with orthopedic injury without any brain injury. SADHD was significantly associated with TBI severity recorded by categorical and dimensional measures, intellectual and adaptive functioning deficits, and personality change due to TBI, but not with lesion area or location. These results suggest that SADHD is a clinically important syndrome after severe TBI in children and adolescents.