Dissociation of frequency and recency processing from list recall after severe closed head injury in children and adolescents.

To investigate judgment of the frequency and recency of events relative to word list recall in children following closed head injury (CHI), 124 children and adolescents, including 79 severe CHI patients (mean age at test = 13.2 years), 27 mild CHI cases (mean age at test = 12.1 years), and 18 uninjured comparison subjects (mean age = 12.8 years) were studied. The mean postinjury interval was 63.6 months for the severe and 46.7 months for the mild CHI groups. The experimental tasks included estimation of the frequency of presentation of words and designs and recency judgment to select the most recently presented of two stimuli on verbal (words) and nonverbal (faces) tasks. To compare frequency and recency judgments to performance on a task which has been shown to be sensitive to CHI severity and age at test, verbal recall was tested using the California Verbal Learning Test-Children's Version. Severity of CHI (group) affected verbal recall across trials and after delays, but had no effect on estimating frequency and isolated effects on judgment of recency. Age was also primarily related to verbal recall. A subgroup of severe CHI patients with frontal lesions was impaired on delayed recall. The results are discussed in relation to previous research on the effects of CHI on processing the frequency and recency of events.

Corpus callosum damage and interhemispheric transfer of information following closed head injury in children.

We evaluated the relationship of corpus callosum atrophy and/or lesions on magnetic resonance imaging (MRI) to functional hemispheric disconnection following closed head injury (CHI) in 51 pediatric patients, including mild CHI, moderate to severe CHI with extracallosal lesions, and moderate to severe CHI with callosal atrophy and/or lesions. Interhemispheric transfer of information was assessed using auditory, motor, tactile, and visual tests in patients and in 16 uninjured children. Total and regional callosal areas were measured from the midsagittal MRI slice by morphometry. The corpus callosum lesion group demonstrated a greater right ear advantage on verbal dichotic listening than all other groups. Areas of the posterior corpus callosum were negatively correlated with laterality indices of verbal dichotic listening performance and tachistoscopic identification of verbal material. The relationship of corpus callosum atrophy and/or lesions to asymmetry in dichotic listening is consistent with previous investigation of posttraumatic hemispheric disconnection effects in adults.

Magnetic resonance imaging in relation to functional outcome of pediatric closed head injury: a test of the Ommaya-Gennarelli model.

OBJECTIVE: To characterize late neuropathological findings of pediatric closed head injury (CHI), to assess depth of brain lesion in relation to acute severity, and to assess long-term outcome to test the Ommaya-Gennarelli model. METHODS: Magnetic resonance imaging (MRI) at least 3 months postinjury in a prospective sample (n 5 169) and at least 3 years after CHI in a retrospective sample (n 5 82) was studied. Lesion volume was measured by planimetry. Acute CHI severity was measured by the Glasgow Coma Scale. Patients were classified according to the depth of the deepest parenchymal lesion into no lesion, subcortical, and deep central gray/brain stem groups. The outcomes were assessed by the Glasgow Outcome Scale and the Vineland Adaptive Behavior Scale, which were performed at the time of the MRI in the retrospective sample and up to 3 years postinjury in the prospective sample. RESULTS: Focal brain lesions were present in 55.4% of the total sample. Depth of brain lesion was directly related to severity of acute impairment of consciousness and inversely related to outcome, as measured by both the Glasgow Outcome Scale and the Vineland Adaptive Behavior Scale. A rostrocaudal gradient of hemispheric lesion frequency was observed, whereas the posterior lesions of the corpus callosum were particularly common. Total lesion volume could not explain the depth of lesion effect. CONCLUSION: Our findings extend support for the Ommaya-Gennarelli model to pediatric CHI, indicating that depth of brain lesion is related to functional outcome. The relative frequency of focal brain lesions revealed by late MRI is higher than that of previous findings using acute computed tomography. Future investigations could explore whether depth of lesion observed using late MRI is sensitive to neuroprotective interventions.

Concept formation and problem-solving following closed head injury in children.

To further investigate the usefulness of 3 purported measures of executive function (EF) in head injured children, we administered the Twenty Questions Test (TQT), Tower of London (TOL), and the Wisconsin Card Sorting Test (WCST) to 151 children who had sustained a closed head injury (CHI) of varying severity about 3 years earlier. In addition, we tested 89 normal controls. Fifty-seven of the patients were included in a longitudinal study that compared performance at 3 months and 36 months. All of the head injured children underwent magnetic resonance imaging for investigational purposes. Severity of CHI, as defined by the lowest Glasgow Coma Scale (GCS) score, affected performance on all 3 EF measures. Focal lesion volume incremented prediction of performance on TOL and WCST, but not TQT. Moderate intercorrelations of the test variables were obtained. Although all three EF measures depicted changes in performance over 3 years, a ceiling effect detracted from the sensitivity of the TOL to the impact of CHI on development. Implications of the findings for clinical applications are discussed.

Behavioral outcomes after pediatric closed head injury: relationships with age, severity, and lesion size.

This study investigated the behavioral outcomes and adaptive functioning of 138 children with mild to severe closed head injury in the 6- to 16-year age range. Each child was evaluated with the Personality Inventory for Children-Revised. A subset of this sample (n = 77) received the Vineland Adaptive Behavior Scales. Results revealed little evidence for group differences based on severity of closed head injury on scales associated with psychopathology on the Personality Inventory for Children-Revised. However, children with severe closed head injury were viewed as experiencing more difficulties than children with mild-moderate closed head injury on those components of the Personality Inventory for Children-Revised most closely associated with cognitive functions. In addition, on the Vineland Adaptive Behavior Scales, severely injured children had lower scores on the Communication and Socialization scales than children with mild-moderate injury. Relationships between the size of frontal and extrafrontal lesions from concurrent magnetic resonance imaging and behavioral outcomes were not apparent. This study suggests that outcome measures assessing adaptive behavior and cognitive functions are more sensitive to severity of closed head injury than parent-based scales of internalizing and externalizing psychopathology.

Dissociation between delayed alternation and memory after pediatric head injury: relationship to MRI findings.

This study investigated the usefulness of a delayed alternation task in characterizing the cognitive sequelae of closed head injury in children and adolescents. Verbal learning and memory (California Verbal Learning Test) were also studied for comparison. Sixty-two closed head injury patients (mean age, 9.6 years), who were studied after an average postinjury interval of 20 months, were divided according to both their lowest postresuscitation Glasgow Coma Scale score (3 to 8 versus 9 to 15) and age range (5 to 7 years versus 8 to 16 years) at the time of testing. Magnetic resonance imaging was performed to evaluate the relationship of focal brain lesions to cognitive and memory performance. Fifty-six neurologically normal children (mean age, 9.9 years) were tested on the same measures. The results disclosed no relationship between delayed alternation performance and severity of injury. In contrast, verbal memory was impaired in the severely-injured patients, relative to both controls and less severely-injured patients. Frontal lobe (but not extrafrontal) lesion size incremented the Glasgow Coma Scale score in predicting verbal memory, but there was no relationship between focal brain lesions and delayed alternation performance. In contrast to the tendency for more efficient delayed alternation performance in the 5- to 7-year-old subjects than in the 8- to 16-year-old subjects, verbal memory significantly improved with age in the closed head injury and control groups. Notwithstanding our essentially negative findings for delayed alternation, it is possible that this task may be useful for assessing frontal lobe injury in younger children or infants.(ABSTRACT TRUNCATED AT 250 WORDS)

Cognition in relation to magnetic resonance imaging in head-injured children and adolescents.

To investigate the relationship between cognitive sequelae and magnetic resonance imaging (MRI) findings following closed head injury of varying severity in the pediatric age range, 76 head-injured children and adolescents were studied at least 3 months after trauma and compared with 57 normal controls. Problem solving, planning, verbal and design fluency, memory, and response modulation were assessed. Significant effects of injury were obtained on all of the cognitive measures. Cognitive impairment was more consistently present on the various outcome measures in children who were 6 to 10 years old at the time of the study than in the older children and adolescents. Magnetic resonance imaging disclosed areas of abnormal signal in the frontal lobes of 42 patients, whereas focal lesions restricted to the extrafrontal region were found in 15 children. Regression analyses disclosed that taking into account the size of frontal lobe lesion enhanced the relationship between cognitive performance and the severity of injury.

Reversibility of cerebral atrophy after head injury in children.

Reversible cerebral atrophy in humans has been documented by computed tomography in alcoholics and has been described as an incidental finding after head injury in children. Two children were studied who had sustained a severe closed head injury, 1 and 5 years previously, after which cerebral atrophy had developed, according to subacute computed tomography. Reversible cerebral atrophy was seen on magnetic resonance images of both patients. Despite normal appearance on magnetic resonance images more than 1 year after injury, both patients exhibited residual neuropsychological impairment on a broad range of cognitive and memory tests.

Late MRI after head injury in children: relationship to clinical features and outcome.

To characterize the brain pathology in relation to long-term outcome after pediatric head injury, 55 children were studied by magnetic resonance imaging (MRI) at least 3 months after sustaining moderate to severe closed head injury (CHI). Thirty-nine of the patients had abnormal signal intensity consistent with residual brain lesions, including 28 children with lesions involving the frontal lobes. The clinical features of children with frontal lesions, extrafrontal lesions, and diffuse injury were compared. The analysis disclosed that children with frontal lobe lesions were more frequently disabled than children who sustained diffuse injury. Our MRI findings indicate that residual brain lesions are more common after moderate to severe CHI in children than previously thought and that the frontal lobes are most frequently involved. Further investigation is indicated to elucidate whether distinctive cognitive and behavioral sequelae are associated with frontal lobe lesions in children.

Narrative discourse after closed head injury in children and adolescents.

This study examined narrative discourse in 20 children and adolescents at least 1 year after sustaining a head injury. Narratives were analyzed along the dimensions of language structure, information structure, and flow of information. Severity of impaired consciousness was associated with a significant reduction in the amount of language and information. The most important finding which emerged was the disruption in information structure. This pattern confirms the impression of disorganized discourse in severely injured children. Explanations for the disruption in information structure are explored in terms of the role of vocabulary, memory, and localization of lesion according to magnetic resonance imaging. In view of recent evidence that frontal lobe damage is associated with discourse formulation deficits in adults and is the most common site of focal lesion in closed head injury, we examined discourse patterns in individual patients with frontal lobe lesions. Preliminary data from our single-case studies suggest discourse patterns similar to those reported for adults with frontal lobe injuries.

Corpus callosum lesions after closed head injury in children: MRI, clinical features and outcome.

Thirty-four children who sustained moderate to severe closed head injury underwent magnetic resonance imaging (MRI). Eight (24%) had MRI evidence of corpus callosum injury, most commonly within the posterior body and splenium. In contradistinction to reports in adults, there was no definite relationship between callosal injury and lower initial Glasgow Coma Scale scores, nor was there a significantly higher incidence of primary brain-stem lesions, diffuse axonal shear injury or intraventricular hemorrhage. In none of these 8 children did the initial admission computed tomography show evidence of callosal injury. Callosal injuries on MRI are not necessarily a poor prognostic finding, the majority of the 8 children showing good functional recovery.