Traumatic brain injury and secondary attention-deficit/hyperactivity disorder in children and adolescents: the effect of reward on inhibitory control

Poor inhibitory control and abnormalities in responding to rewards are characteristic of the developmental or primary form of attention-deficit/hyperactivity disorder (P-ADHD). A secondary form of ADHD (S-ADHD) may occur as a consequence of childhood traumatic brain injury (TBI), but the similarities and differences between these two forms of ADHD have not been well characterized. To address these issues, we studied two inhibitory control tasks under different reward conditions in four groups of children and adolescents: TBI who did not exhibit S-ADHD, TBI who did exhibit S-ADHD, P-ADHD, and healthy controls. Participants with TBI exhibited poor cancellation inhibition relative to controls. Although reward facilitated both cancellation and restraint inhibition similarly across groups, poor performance persisted in the P-ADHD group, and participants with S-ADHD exhibited a selective deficit in cancellation inhibition.     

Long-term attention problems in children with traumatic brain injury

OBJECTIVE: To examine long-term attention problems and their cognitive correlates after childhood traumatic brain injury (TBI). METHOD: Data were drawn from a prospective, longitudinal study conducted between 1992 and 2002. Participants included 41 children with severe TBI, 41 with moderate TBI, and 50 with orthopedic injury (OI), who were all between 6 and 12 years of age at the time of injury. Parent ratings of attention problems were obtained at a long-term follow-up on average 4 years post-injury and compared with ratings of premorbid attention problems obtained shortly after injury. At the long-term follow-up, children also completed several cognitive tests of attention and executive functions. RESULTS: Hierarchical linear and logistic regression analyses indicated that the severe TBI group displayed significantly more attention problems than the OI group at 4 years post-injury, both behaviorally and cognitively, after controlling for race, socioeconomic status, and premorbid attention problems. At long-term follow-up, 46% of the severe TBI group displayed significant attention problems on the Child Behavior Checklist, as opposed to 26% of the OI group (odds ratio=3.38; 95% confidence interval, 1.15-9.94). On the Attention-Deficit/Hyperactivity Disorder Rating Scale, 20% of the severe TBI group displayed clinically significant attention problems compared with 4% in the OI group (odds ratio=9.59; 95% confidence interval, 1.24-73.99). However, group differences in behavioral symptoms were significantly larger for children with more premorbid symptoms than for children with fewer premorbid problems. Measures of executive functions were significantly related to behavioral attention problems, after controlling for group membership, race, and socioeconomic status. CONCLUSIONS:Childhood TBI exacerbates premorbid attention problems. Long-term behavioral symptoms of attention problems are related to the cognitive deficits in attention and executive functions that often occur in association with childhood TBI.     

Predicting premorbid neuropsychological functioning following pediatric traumatic brain injury

Abstract

This study examined the prediction of premorbid neuropsychological functioning using data from an ongoing prospective study of traumatic brain injuries (TBI) in children ages 6 to 12 years. Prediction equations were derived based on 80 children with orthopedic injuries (OI), who served as a comparison group for the children with TBI. Collectively, parent ratings of premorbid school performance, maternal ethnicity, family socioeconomic status, and children's word recognition skill predicted from 13% to 45% of the variance in three measures of neuropsychological functioning. The regression equations were used to compute predicted scores among 109 children with TBI. Actual scores fell significantly below predicted scores among children with TBI, and the magnitude of the deficits was correlated with injury severity. Premorbid neuropsychological functioning can be predicted in children with TBI, but with less precision than would be desirable for clinical purposes.     

Encoding and recognition after traumatic brain injury: neuropsychological and functional magnetic resonance imaging findings

Although impairment of episodic memory is common after traumatic brain injury (TBI), the complex nature of human memory suggests the need to study more than recall alone. For this reason, we are presenting an extension with additional analyses of persons reported in a previous publication ( Russell, Arenth, Scanlon, Kessler, & Ricker, 2011 ). We examined both the encoding and recognition components of an episodic memory paradigm containing both word and letter string blocks using functional magnetic resonance imaging (fMRI) and neuropsychological testing. This paradigm was completed by 12 persons with complicated mild, moderate, or severe TBI and 12 matched uninjured controls. Comparisons were made between groups and stimulus types. While task behavioral performance was not significantly different between groups, imaging results showed greater activation for the TBI group during the encoding portion of the task, while the control group exhibited more activation on the recognition portion. Observed areas of activation suggest that the TBI group may have used a less effective, but more automatic verbal strategy for encoding the nonpronounceable letter strings, while controls may have opted for more of a recognition-focused strategy. Group differences in California Verbal Learning Test-Second Edition (CVLT-II) performance supported these ideas, and further neuropsychological testing also suggested limitations in executive functioning in the TBI group that may have influenced performance. Implications for intervention are discussed.     

Impact of neurocognitive function on academic difficulties in pediatric bipolar disorder: A clinical translation.

BACKGROUND: Previous research has demonstrated that academic and neuropsychological functions are compromised in pediatric bipolar disorder (PBD). Investigation of the degree to which neuropsychological deficits might contribute to those academic problems is needed to aid in the recognition and intervention for school achievement difficulties in PBD. METHODS: A sample of 55 children and adolescents with PBD with and without attention-deficit/hyperactivity disorder (ADHD) (PBD group, n = 28; PBD+ADHD group, n = 27) were tested with a computerized neurocognitive battery and standardized neuropsychological tests. Age range of subjects was 7-17 years, with the mean age of 11.97 (3.18) years. Parents completed a structured questionnaire on school and academic functioning. RESULTS: Logistic regression analyses indicated that executive function, attention, working memory, and verbal memory scores were poorer in those with a history of reading/writing difficulties. A separate logistic regression analysis found that attentional dysfunction predicted math difficulties. These relationships between neuropsychological function and academic difficulties were not different in those with PBD+ADHD than in those with PBD alone. CONCLUSIONS: In PBD neuropsychological deficits in the areas of attention, working memory, and organization/problem solving skills all contribute to academic difficulties. Early identification and intervention for these difficulties might help prevent lower academic achievement in PBD.     

Neuropsychological dysfunction in depressed suicide attempters

OBJECTIVE: Neuropsychological deficits in the context of psychiatric disease may be associated with suicide risk. In this study, neuropsychological performance was compared among depressed patients with at least one prior suicide attempt of high lethality, depressed patients with low-lethality prior attempts, depressed patients with no prior suicide attempts, and nonpatients. METHOD: Fifty unmedicated patients in a major depressive episode (21 with no history of suicide attempts and 14 and 15 patients with previous attempts of low and high lethality, respectively) and 22 nonpatients were assessed. Groups were comparable in age, education, occupational level, and estimated premorbid intelligence. The neuropsychological battery produced scores within five composite domains: general intellectual functioning (current), motor functioning, attention, memory, and executive functioning. RESULTS: Patients whose prior suicide attempts were of high lethality performed significantly worse than all groups on tests of executive functioning and were the only group to perform significantly worse than nonpatients on tests of general intellectual functioning, attention, and memory. A discriminant function analysis revealed two prominent dimensions in the data: one that discriminated high-lethality suicide attempters from all other groups (primarily associated with performance on tests of executive functioning) and another that discriminated all depressed patient groups from nonpatients (associated with performance on measures of attention and memory). For the patients with high-lethality prior suicide attempts, deficits did not appear to reflect diffuse brain damage from past attempts, since the results of tests commonly affected by diffuse injury were not selectively impaired. CONCLUSIONS: Neuropsychological deficits in depressed patients with high-lethality prior suicide attempts suggest impairment of executive functioning beyond that typically found in major depression. This more extensive neuropsychological impairment in the context of depression may be a risk factor for severe suicide attempts.     

The effect of premorbid attention-deficit/hyperactivity disorder on neuropsychological functioning in individuals with acute mild traumatic brain injuries

Introduction. Mild traumatic brain injury (mTBI) is a frequent, yet undertreated condition that typically manifests with transient neurological and cognitive symptoms that resolve over the course of several weeks. In contrast, attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that presents initially in childhood but often persists into adulthood. mTBI and ADHD include overlapping symptomatology, making it difficult for clinicians to disentangle the sequelae of each condition when they co-occur in the same individual. We hypothesized that neuropsychological tests would be sensitive to preexisting ADHD in inpatients with acute mTBIs. Method. We retrospectively examined the medical charts of 100 inpatients, aged 18–40 years (96% Caucasian; 77% male) with mTBIs in an acute care setting, half of whom had self-reported the presence of premorbid ADHD, and half of whom were matched controls. We analyzed group differences across neuropsychological tests of attention, processing speed, and executive functions, examined the profile ratings of independent, blinded, board-certified neuropsychologists, and correlated cognitive performance with time from traumatic injury to testing. Results. Individuals with premorbid ADHD (a) performed significantly worse than their matched counterparts on several tests of attention, processing speed, and working memory, and (b) were significantly more likely to produce profiles later rated as impaired by independent, board-certified clinical neuropsychologists. In addition, time from traumatic injury to testing was found to be negatively correlated with neurocognitive performance. Conclusions. These findings (a) argue for the utility of a brief assessment of premorbid ADHD in the acute care of individuals with mTBIs and (b) provide clinicians with a barometer for gauging the relative contributions of premorbid ADHD to neuropsychological impairments in the neurocognitive profiles of individuals with mTBIs. Reported effect sizes will assist clinicians in accurately weighing the impact of premorbid ADHD when interpreting such profiles.     

Attention and executive functions profile in drug naive ADHD subtypes

Attention deficit hyperactivity disorder (ADHD) has been associated with executive functioning and sustained and divided attention deficits. In order to clarify the questions on neurocognitive impairment in ADHD, we investigated the presence of specific executive functions (EFs) and attention deficit patterns in ADHD clinical subtypes. 50 patients with ADHD and 44 controls were evaluated. All subjects were boys and performed a clinical-psychopathological and neuropsychological battery. Five main domains of EFs and attention were studied. Executive functions-related neurocognitive abilities were used as control tasks. ADHD patients, inattentive and combined subtypes differ from controls on response inhibition, divided attention, phonological, and visual object working memory and on variability of reaction times measured with CPT. Comparison of ADHD subtypes, in five main domains of EFs, did not show evidence of different executive functioning profiles. Response inhibition can predict performance on working memory tests but it cannot predict performance on divided attention/set shifting and on sustained attention. ADHD boys exhibit a selective impairment on executive functions and attention tasks. These data suggest the involvement of partially independent neural circuits which control inhibition and divided attention in ADHD. Since right prefrontal cortex seems to be crucial in controlling response inhibition, while left dorsolateral prefrontal cortex seems important in modulating divided attention, these areas are deputated to be involved in the pathogenesis of neuropsychological deficits in ADHD subtypes. In addition, this study candidates the impairment in phonological and visual-object working memory as a possible neuropsychological trait in ADHD males with inattentive or combined subtypes.     

Identifying factors contributing to child and family outcome 30 months after traumatic brain injury in children

OBJECTIVE: To examine the contributions of injury severity, physical and cognitive disability, child and family function to outcome 30 months after traumatic brain injury (TBI) in children. DESIGN: A prospective, longitudinal, between group design, comparing function before and after injury across three levels of injury severity. SUBJECTS: One hundred and fifty children, 3.0-12.11 years old, admitted to hospital with a diagnosis of TBI. The sample was divided according to injury severity: mild (n = 42), moderate (n = 70), severe (n = 38). Children with a history of neurological, developmental, and psychiatric disorders were excluded from participation. MAIN OUTCOME MEASURES: Post injury physical function, cognitive ability (incorporating intellect, memory, and attention), behavioural and family functioning, and level of family burden. RESULTS: A dose-response relation was identified for injury severity and physical and cognitive outcome, with significant recovery documented from acute to six months after TBI. Behavioural functioning was not related to injury severity, and where problems were identified, little recovery was noted over time. Family functioning remained unchanged from preinjury to post injury assessments. The level of family burden was high at both six and 30 months after injury, and was predicted by injury severity, functional impairment, and post injury child behavioural disturbance. CONCLUSIONS: These results suggest ongoing problems for the child and significant family burden 30 months after TBI. The nature and severity of the physical and cognitive problems are closely related to injury severity, with child and family function predicted by psychosocial and premorbid factors.     

Dementia after traumatic brain injury

Early retrospective studies suggested that individuals with a history of a traumatic brain injury (TBI) had a higher risk for dementia than those without a history of TBI. Two meta-analyses demonstrated that the risk for dementia is higher among men, but not women, with a history of TBI. More recent prospective studies, however, are providing discrepant findings, probably due to important methodological differences. TBI is usually associated with significant neuropsychological deficits, primarily in the domains of attention, executive functioning and memory. These deficits may not improve with time. TBI may also lower the threshold for the clinical expression of dementia among predisposed individuals, and the onset of Alzheimer's disease (AD)-like neuropathological and biochemical changes immediately after severe TBI may play an important role in this mechanism.     

Stability of employment after traumatic brain injury.

Although substantial information exists about factors related to who returns to work and time taken to return to work after traumatic brain injury (TBI), less is known about the stability of the work experience after the injury. One hundred sixty-five workers with complicated mild to severe traumatic brain injury were followed for 3 to 5 years postinjury. Work stability definitions included amount of time worked (amount of time worked divided by time observed postinjury) and maintenance of uninterrupted employment once a person returned to work. Amount of time worked was significantly and systematically related to brain injury severity, neuropsychological functioning at l-month postinjury, and preinjury characteristics such as prior work stability and earnings. However, once persons returned to work, the ability to maintain uninterrupted employment was largely related to premorbid characteristics such as being older, higher income before the injury, or a preinjury job with benefits. It was also related to higher neuropsychological functioning at 1-month postinjury (reflecting the combined effects of premorbid functioning and traumatic brain injury severity), but not related to neurologic indices of severity.     

The effect of traumatic brain injury on children with learning disability

The psychometric performance of 10 children with a history of learning disability (LD) who subsequently experienced a moderate to severe traumatic brain injury (TBI) was evaluated. Compared to premorbid data, children with LD experienced, after TBI, a statistically significant decline on a measure of psychometric intelligence, whereas their performance on measures of academic achievement remained stable. On specific neuropsychological measures, children with LD and TBI did not differ significantly post-injury from matched controls who also had TBI but no prior history of LD. It is concluded that moderate to severe TBI can cause significant additional cognitive impairment in children with LD, and that periodic modifications in the academic curriculum of these children are often needed after injury. Comparison of premorbid and postmorbid psychometric test data is crucial in this respect.     

Premorbid child and family functioning as predictors of post-concussive symptoms in children with mild traumatic brain injuries

Study aim

This study sought to determine whether premorbid child and family functioning accounts for or moderates group differences in post-concussive symptoms following mild traumatic brain injury (TBI) in childhood.

Methods

This prospective, longitudinal cohort study recruited 8- to 15-year-old children, 186 with mild TBI and 99 with orthopedic injuries (OI), from consecutive emergency department admissions. Parents and children rated post-concussive symptoms within 3 weeks of injury and at 1, 3, and 12 months post injury. Parents also provided retrospective ratings of pre-injury symptoms, as well as of premorbid child behavioral adjustment, overall family functioning, and other stressors and resources in the family environment.

Results

Children with mild TBI reported more post-concussive symptoms than those with OI, as did their parents, although premorbid child behavioral adjustment and symptoms also were significant predictors of post-concussive symptoms. Group differences in somatic symptoms as reported by parents were more pronounced among children from families that were higher functioning and had more environmental resources.

Discussion

Mild TBI during childhood results in more post-concussive symptoms than OI, even after children's premorbid adjustment is taken into account. Counter to expectations, post-concussive symptoms following mild TBI may actually be more apparent among children from higher-functioning families with greater resources.     

Attention following traumatic brain injury: Neuropsychological and driving simulator data,and association with sleep,sleepiness, and fatigue

The objectives of this study were to compare individuals with traumatic brain injury (TBI) and healthy controls on neuropsychological tests of attention and driving simulation performance, and explore their relationships with participants’ characteristics, sleep, sleepiness, and fatigue. Participants were 22 adults with moderate or severe TBI (time since injury ≥ one year) and 22 matched controls. They completed three neuropsychological tests of attention, a driving simulator task, night-time polysomnographic recordings, and subjective ratings of sleepiness and fatigue. Results showed that participants with TBI exhibited poorer performance compared to controls on measures tapping speed of information processing and sustained attention, but not on selective attention measures. On the driving simulator task, a greater variability of the vehicle lateral position was observed in the TBI group. Poorer performance on specific subsets of neuropsychological variables was associated with poorer sleep continuity in the TBI group, and with a greater increase in subjective sleepiness in both groups. No significant relationship was found between cognitive performance and fatigue. These findings add to the existing evidence that speed of information processing is still impaired several years after moderate to severe TBI. Sustained attention could also be compromised. Attention seems to be associated with sleep continuity and daytime sleepiness; this interaction needs to be explored further.     

Premorbid factors in relation to motor,memory, and executive functions deficits in adult schizophrenia

This study examined two areas of premorbid adjustment (attentional functioning and social adaptation) and three areas of adult neuropsychological performance (executive functions, learning/memory, and motor functions) in a clinically stable outpatient sample of schizophrenics (n=61). The study examined three components of premorbid attentional functioning (concentration, hyperactivity, and requiring supervision for organizing activities or tasks) and three components of premorbid social adaptation (socialization skills, disciplinary problems, and antisocial behavior) in relation to the neuropsychological variables assessed in adulthood. Findings indicated that premorbid difficulties in all three attentional functioning areas and two of the three social functioning areas were related to adult neuropsychological performance. Childhood concentration deficits were not as significant an influence as distractibility on adult neuropsychological functioning, nor was excessive premorbid activity level as important as inhibiting impulsivity. Premorbid socialization deficits were related to motor dysfluency in adulthood. A history of disciplinary problems but not antisocial behavior in childhood had an adverse influence on adult neuropsychological deficits. This study demonstrated selective influences of premorbid attentional and social adjustment impairments on a broad range of cognitive abilities in adult schizophrenia.     

Cognitive impairment in euthymic bipolar patients: implications for clinical and functional outcome

OBJECTIVE: Cognitive impairment in bipolar disorder may be a stable characteristic of the illness, although discrepancies have emerged with regard to what dysfunctions remain during remission periods. The aim of this study was to ascertain whether euthymic bipolar patients would show impairment in verbal learning and memory and in executive functions compared with healthy controls. Secondly, to establish if there was a relationship between clinical data and neuropsychological performance. METHODS: Forty euthymic bipolar patients were compared with 30 healthy controls through a battery of neuropsychological tests assessing estimated premorbid IQ, attention, verbal learning and memory, and frontal executive functioning. The effect of subsyndromal symptomatology was controlled. RESULTS: Remitted bipolar patients performed worse than controls in several measures of memory and executive function, after controlling for the effect of subclinical symptomatology, age and premorbid IQ. Verbal memory impairment was related to global assessment of function scores, as well as to a longer duration of illness, a higher number of manic episodes, and prior psychotic symptoms. CONCLUSIONS: Results provide evidence of neuropsychological impairment in euthymic bipolar patients, after controlling for the effect of subsyndromal depressive symptoms, suggesting verbal memory and executive dysfunctions. Cognitive impairment seems to be related to a worse clinical course and poor functional outcome.     

Working memory after severe traumatic brain injury.

The aim of the present study was to assess the functioning of the different subsystems of working memory after severe traumatic brain injury (TBI). A total of 30 patients with severe chronic TBI and 28 controls received a comprehensive assessment of working memory addressing the phonological loop (forward and backward digit span; word length and phonological similarity effects), the visuospatial sketchpad (forward and backward visual spans), and the central executive (tasks requiring simultaneous storage and processing of information, dual-task processing, working memory updating). Results showed that there were only marginal group differences regarding the functioning of the two slave systems, whereas patients with severe TBI performed significantly poorer than controls on most central executive tasks, particularly on those requiring a high level of controlled processing. These results suggest that severe TBI is associated with an impairment of executive aspects of working memory. The anatomic substrate of this impairment remains to be elucidated. It might be related to a defective activation of a distributed network, including the dorsolateral prefrontal cortex.     

Association between cognitive impairments and obsessive-compulsive spectrum presentations following traumatic brain injury

This study examined the association between self-reported obsessive-compulsive spectrum symptomatology and cognitive performance in a sample of patients with traumatic brain injury (TBI). Twenty-four adults with a moderate-severe TBI accessing a community brain injury rehabilitation service were recruited. Age ranged between 19 and 69 years. Participants completed a battery of neuropsychological tasks assessing memory, executive functioning, and speed of information processing. Self-report questionnaires assessing obsessive-compulsive (OC) symptoms and obsessive-compulsive personality disorder (OCPD) traits were also completed. Correlational analyses revealed that deficits in cognitive flexibility were associated with greater self-reported OC symptomatology and severity. Greater OC symptom severity was significantly related to poorer performance on a visual memory task. Verbal memory and speed of information processing impairments were unrelated to OC symptoms. Performance on tasks of memory, executive functioning, and speed of information processing were not associated with OCPD traits. Overall, results indicate that greater OC symptomatology and severity were associated with specific neuropsychological functions (i.e., cognitive flexibility, visual memory). OCPD personality traits were unrelated to cognitive performance. Further research is needed to examine the potential causal relationship and longer-term interactions between cognitive sequelae and obsessive-compulsive spectrum presentations post-TBI.     

Executive function as a predictor of inattentive behavior after traumatic brain injury.

Emerging evidence from recent studies using laboratory and naturalistic attention tasks suggests that individuals with traumatic brain injury (TBI) may have a deficit mainly in strategic control of attention. In the present study, we tested the hypothesis that inattentive behavior after TBI could be predicted by performance on psychometric measures of executive function. A group of 37 individuals with moderate to severe TBI were assessed with previously validated naturalistic measures of attention. A battery of neuropsychological tests was also administered to assess various aspects of executive function. Seven measures of executive function and 10 variables reflecting inattentive behavior were combined to form 1 executive and 3 inattentive behavior (IB) composite scores. Three predictors (executive composite, current disability scores, and age) were associated, at the univariate level, with one of the IB composites reflecting frequency and duration of off-task episodes. A stepwise multiple regression procedure indicated that the executive composite was the only significant predictor of the IB composite. Additional post-hoc regression analyses suggested that the relationship was not likely to be mediated by processing speed. The current study supports the hypothesis that executive function, measured by commonly used neuropsychological tests, significantly predicts certain aspects of inattentive behavior in real-world tasks after TBI.     

Neuropsychological functioning in euthymic bipolar disorder: a meta-analysis

OBJECTIVE: Although cognitive deficits are prominent in symptomatic patients with bipolar disorder, the extent and pattern of cognitive impairment in euthymic patients remain uncertain. METHOD: Neuropsychological studies comparing euthymic bipolar patients and healthy controls were evaluated. Across studies, effect sizes reflecting patient-control differences in task performance were computed for the 15 most frequently studied cognitive measures in the literature. RESULTS: Across the broad cognitive domains of attention/processing speed, episodic memory, and executive functioning, medium-to-large performance effect size differences were consistently observed between patients and controls, favoring the latter. Deficits were not observed on measures of vocabulary and premorbid IQ. CONCLUSION: Meta-analytic findings provide evidence of a trait-related neuropsychological deficit in bipolar disorder involving attention/processing speed, memory, and executive function. Findings are discussed with regard to potential moderators, etiologic considerations, limitations, and future directions in neuropsychological research on bipolar disorder.