Biomedical subjects

Sandra B Chapman

Publications and source records attributed to Sandra B Chapman.

10 recordsLinked to original sources

PubMed2006

A SPECT study of language and brain reorganization three years after pediatric brain injury.

Using single photon emission computed tomography (SPECT), we investigated brain plasticity in children 3 years after sustaining a severe traumatic brain injury (TBI). First, we assessed brain perfusion patterns (i.e., the extent of brain blood flow to regions of the brain) at rest in eight children who suffered severe TBI as compared to perfusion patterns in eight normally developing children. Second, we examined differences in perfusion between children with severe TBI who showed good versus poor recovery in complex discourse skills. Specifically, the children were asked to produce and abstract core meaning for two stories in the form of a lesson. Inconsistent with our predictions, children with severe TBI showed areas of increased perfusion as compared to normally developing controls. Adult studies have shown the reverse pattern with TBI associated with reduced perfusion. With regard to the second aim and consistent with previously identified brain-discourse relations, we found a strong positive association between perfusion in right frontal regions and discourse abstraction abilities, with higher perfusion linked to better discourse outcomes and lower perfusion linked to poorer discourse outcomes. Furthermore, brain-discourse patterns of increased perfusion in left frontal regions were associated with lower discourse abstraction ability. The results are discussed in terms of how brain changes may represent adaptive and maladaptive plasticity. The findings offer direction for future studies of brain plasticity in response to neurocognitive treatments.

Brain Injuries↗

PubMed2006

Predictors of personality change due to traumatic brain injury in children and adolescents six to twenty-four months after injury.

Phenomenology and predictive factors of personality change due to traumatic brain injury (TBI) 6 to 24 months after injury was investigated in children, ages 5 to 14 years, enrolled from consecutive admissions and followed prospectively for 2 years. Injury and preinjury psychosocial variables were assessed. Personality change occurred in 13% of participants between 6 and 12 months after injury and 12% in the second year after injury. Severity of injury consistently predicted personality change, and preinjury adaptive function predicted personality change only in the second year postinjury. Lesions of the superior frontal gyrus were associated with personality change between 6 and 12 months following injury, after controlling for severity of injury and the presence of other brain lesions. Only lesions in the frontal lobe white matter were significantly related to personality change in the second year after injury. After childhood TBI, neural correlates of personality change evolve between 6 and 12 months and 12 to 24 months after injury. The data implicate the dorsal prefrontal cortex and frontal lobe white matter in the emergence of personality change involving the effortful or conscious regulation of affective states.

Adolescent↗

PubMed2005

Impaired discourse gist and working memory in children after brain injury.

Emerging evidence suggests that a traumatic brain injury (TBI) in childhood may disrupt the ability to abstract the central meaning or gist-based memory from connected language (discourse). The current study adopts a novel approach to elucidate the role of immediate and working memory processes in producing a cohesive and coherent gist-based text in the form of a summary in children with mild and severe TBI as compared to typically developing children, ages 8-14 years at test. Both TBI groups showed decreased performance on a summary production task as well as retrieval of specific content from a long narrative. Working memory on n-back tasks was also impaired in children with severe TBI, whereas immediate memory performance for recall of a simple word list in both TBI groups was comparable to controls. Interestingly, working memory, but not simple immediate memory for a word list, was significantly correlated with summarization ability and ability to recall discourse content.

Adolescent↗

PubMed2005

Predictors of personality change due to traumatic brain injury in children and adolescents in the first six months after injury.

OBJECTIVE: To assess the phenomenology and predictive factors of personality change due to traumatic brain injury. METHOD: Children (N = 177), aged 5 to 14 years with traumatic brain injury from consecutive admissions to five trauma centers, were followed prospectively at baseline and 6 months with semistructured psychiatric interviews. Injury severity, lesion characteristics, and preinjury variables including psychiatric disorder, family psychiatric history, family function, socioeconomic status, psychosocial adversity, and adaptive function were assessed with standardized instruments. RESULTS: Personality change occurred in 22% of participants in the first 6 months after injury. Severity of injury predicted personality change, whereas none of the psychosocial variables predicted personality change. Lesions of the dorsal prefrontal cortex, specifically the superior frontal gyrus, were associated with personality change after controlling for severity of injury or the presence of other lesions. CONCLUSIONS: These findings are consistent with models of affective dysregulation that implicate a dorsal prefrontal cortex system important for effortful regulation of affective states.

Adolescent↗

PubMed2005

Predictors of secondary attention-deficit/hyperactivity disorder in children and adolescents 6 to 24 months after traumatic brain injury.

OBJECTIVE: To assess the phenomenology and predictive factors of attention-deficit/hyperactivity disorder (ADHD) after traumatic brain injury (TBI), also called secondary ADHD (SADHD). METHOD: Children without preinjury ADHD 5-14 years old with TBI from consecutive admissions (n = 143) to five trauma centers were observed prospectively from 6 to 12 months (12-month assessment) and from 12 to 24 months (24-month assessment) postinjury with semistructured psychiatric interviews. Injury and preinjury psychosocial variables were assessed. RESULTS: SADHD occurred in 15 of 103 (15%) of participants between 6 and 12 months after injury and 17 of 82 (21%) in the second year after injury. SADHD was significantly (p < .05) comorbid with personality change due to TBI and new-onset disruptive behavior disorders. Preinjury adaptive function was a consistent predictor of SADHD. Regression analyses revealed that preinjury psychosocial adversity was an independent predictor of SADHD in the second year after injury. Neither severity of injury nor lesion location predicted SADHD from 6 to 24 months postinjury. CONCLUSIONS: Determination of preinjury psychosocial adversity and the child's preinjury functioning during the index hospitalization would improve identification of children at highest risk of development of SADHD.

Adolescent↗

PubMed2005

Predictors of attention-deficit/hyperactivity disorder within 6 months after pediatric traumatic brain injury.

OBJECTIVE: To assess the phenomenology and predictive factors of attention-deficit/hyperactivity disorder (ADHD) after traumatic brain injury (TBI), also called secondary ADHD (SADHD). METHOD: Children without preinjury ADHD 5-14 years old with TBI from consecutive admissions (n = 143) to five trauma centers were observed prospectively for 6 months (baseline and 6 months), with semistructured psychiatric interviews. Injury severity, lesion characteristics, and preinjury variables including psychiatric disorder, family psychiatric history, family psychiatric history of ADHD, family function, socioeconomic status, psychosocial adversity, and adaptive function were assessed with standardized instruments. RESULTS: SADHD in the first 6 months after injury occurred in 18 of 115 (16%) of returning participants. All subtypes of ADHD occurred. Socioeconomic status (p = .041) and orbitofrontal gyrus lesions (p = .005) independently significantly predicted SADHD. CONCLUSIONS: These findings are consistent with research on developmental ADHD that implicate psychosocial factors and prefrontal structural and functional differences between those with and without the disorder.

Adolescent↗

PubMed2004

Verbal selective learning after traumatic brain injury in children.

Selective learning (SL), the ability to select items to learn from among other items, engages cognitive control, which is purportedly mediated by the frontal cortex and its circuitry. Using incentive-based auditory word recall and expository discourse tasks, we studied the efficiency of SL in children ages 6 to 16 years who had sustained severe traumatic brain injury (TBI) at least 1 year earlier. We hypothesized that SL would be compromised by severe TBI. Results indicated that children with severe TBI performed significantly worse than age-matched typically developing children on word- and discourse-level measures of SL efficiency with no significant group differences in number of items recalled from auditory word lists or declarative facts. We conclude that severe TBI disrupts incentive-based cognitive control processes, possibly due to involvement of frontal neural networks.

Acoustic Stimulation↗

PubMed2004

Changes in working memory after traumatic brain injury in children.

The impact of traumatic brain injury (TBI) on working memory (WM) was studied in 144 children (79 with mild, 23 with moderate, and 42 with severe injuries) who underwent magnetic resonance imaging (MRI) at 3 months and were tested at baseline and at 3, 6, 12, and 24 months postinjury. An n-back WM task for letter identity was administered with memory load ranging from 1- to 3-back and a 0-back condition. A TBI Severity x Quadratic Tune interaction showed that net percentage correct (correct detections of targets minus false alarms) was significantly lower in severe than in mild TBI groups. The Left Frontal Lesions x Age interaction approached significance. Mechanisms mediating late decline in WM and the effects of left frontal lesions are discussed.

Adolescent↗

PubMed2004

Three-word recall in normal aging.

Three-word recall tasks are widely used as brief measures of verbal memory function, although interpretation of performance is complicated by variations in test instructions and procedures. The purpose of this study was to examine 3-word recall performance in samples of healthy subjects aged 5275 (M age = 70) and age 7692 (M age = 82) compared to patients with Alzheimer's Disease (AD) when explicit prompts to remember the words were given. Those in the younger aging group remembered significantly more words than those in the older sample after a brief delay (M= 2.8 and 2.3, respectively). However, the majority of control subjects recalled 2 or 3 words after the delay, with only 3% of the 5075 year old group and 17% of the 76+ year old group recalling 0 or 1 word on delayed recall. This is in stark contrast to the 87% of individuals with AD who recalled 0 or 1 word. Even though 3-word recall performance decreases with age, good recall (2 or 3 words) can be expected in most cases of normal aging.

Aged↗

PubMedDate not supplied

Convergence of connected language and SPECT in variants of frontotemporal lobar degeneration.

The characterization of frontotemporal lobar degeneration (FTLD) is complicated and not widely recognized. Connected language measures (ie, discourse) and functional neuroimaging may advance knowledge specifying early distinctions among frontal dementias. The present study examined the correspondence of discourse measures with (1) clinical diagnosis and (2) single photon emission computed tomography (SPECT) imaging. Nineteen subjects were selected from Alzheimer's Disease Center (ADC) participants if they were diagnosed with early-stage frontotemporal lobar degeneration and also underwent single photon emission computed tomography and discourse evaluation. First, clinical diagnoses given by specialists at an Alzheimer's Disease Center were compared with the discourse-based diagnostic profiles. Secondly, compromised brain regions that were predicted from discourse profiles were compared with SPECT findings. Results revealed a significant correspondence between the ADC diagnosis and the discourse-based diagnoses. Also, the discourse profiles across frontotemporal lobar degeneration subtypes were consistently associated with distinctive patterns of SPECT hypometabolism in the right frontal, left frontal, or left temporal lobes. These findings suggest that discourse methods may be systematized to provide an efficient adjunct measure beyond the traditional word and sentential level measures. Objectifying complex language performance may contribute to early detection and differentiation among frontotemporal lobar degeneration variants because consensus in the literature states that language is a core disturbance of frontotemporal lobar degeneration.

Aged↗