Changes in working memory performance in youth following concussion.

OBJECTIVE: The purpose of this study was to compare the working memory (WM) performance pre- and post-concussion, and investigate the relationships between performance changes and characteristics such as self-reported symptom scores, number of days post-injury and age at injury in 10-14-year-old youth. METHODS: Twenty-one youth (17 males) aged 10-14 years recruited from the community completed verbal and non-verbal WM tasks pre- and post-concussion. Performance was measured using accuracy and performance errors (false alarms and misses). Pre- and post-tests were compared using a Wilcoxon signed rank test, and effect size was determined using matched-pairs rank biserial correlation. RESULTS: Comparisons showed lower verbal WM accuracy at post-test, greater verbal and non-verbal WM false alarm errors at post-test, and greater verbal WM miss errors at post-test (all r ≥ 0.30). Correlations between performance and characteristics revealed associations between younger youth and lower non-verbal WM accuracy and more false alarms at post-test, as well as an association among non-verbal WM miss errors, higher PCS scores and fewer days since injury at post-test. CONCLUSIONS: The current study found lower WM performance in youth following concussion. Furthermore, the findings suggest that false alarm errors may be a useful screening measure acutely post-concussion when assessing WM performance in youth.

Psychosocial consequences of mild traumatic brain injury in children: results of a systematic review by the International Collaboration on Mild Traumatic Brain Injury Prognosis.

OBJECTIVE: To synthesize the best available evidence regarding psychosocial consequences of mild traumatic brain injury (MTBI) in children. DATA SOURCES: MEDLINE, Embase, CINAHL, PsycINFO, and SPORTDiscus were searched (2001-2012). Inclusion criteria included published peer-reviewed reports in English, French, Norwegian, Spanish, Swedish, and Danish. References were also identified from relevant reviews and meta-analyses, and the bibliographies of eligible articles. STUDY SELECTION: This article presents an update of a previous review with a much larger scope, of which this topic is a small subset of the questions addressed by that review. Controlled trials and cohort and case-control studies were selected according to predefined criteria. Two independent reviewers used modified Scottish Intercollegiate Guidelines Network criteria to critically appraise eligible studies. A total of 77,914 records were screened; 101 of these articles were deemed scientifically admissible, of which 6 investigated the psychosocial consequences of MTBI in children. DATA EXTRACTION: Two reviewers independently extracted data from accepted studies into evidence tables. DATA SYNTHESIS: We conducted a best-evidence synthesis by linking our conclusions to the evidence tables. Most accepted studies were exploratory rather than confirmatory. Preliminary evidence suggests that most children recover within 3 months post-MTBI. After 1 year, the prevalence of postconcussion symptoms and syndrome is similar between children with MTBI and children with orthopedic injuries. The functional status of children with MTBI improves over a 30-month follow-up period, but further research is needed to investigate the possibility that children with MTBI experience greater rates of psychiatric illness during the 3 years after their injury. CONCLUSIONS: The prognosis of MTBI is favorable in children. Most appear to recover functionally from a physical and psychological perspective. However, future research should investigate the risk for psychiatric illness.

Is there evidence for neurodegenerative change following traumatic brain injury in children and youth? A scoping review.

While generalized cerebral atrophy and neurodegenerative change following traumatic brain injury (TBI) is well recognized in adults, it remains comparatively understudied in the pediatric population, suggesting that research should address the potential for neurodegenerative change in children and youth following TBI. This focused review examines original research findings documenting evidence for neurodegenerative change following TBI of all severities in children and youth. Our relevant inclusion and exclusion criteria identified a total of 16 articles for review. Taken together, the studies reviewed suggest there is evidence for long-term neurodegenerative change following TBI in children and youth. In particular both cross-sectional and longitudinal studies revealed volume loss in selected brain regions including the hippocampus, amygdala, globus pallidus, thalamus, periventricular white matter, cerebellum, and brain stem as well as overall decreased whole brain volume and increased CSF and ventricular space. Diffusion Tensor Imaging (DTI) studies also report evidence for decreased cellular integrity, particularly in the corpus callosum. Sensitivity of the hippocampus and deep limbic structures in pediatric populations are similar to findings in the adult literature and we consider the data supporting these changes as well as the need to investigate the possibility of neurodegenerative onset in childhood associated with mild traumatic brain injury (mTBI).

A functional magnetic resonance imaging study of working memory in youth after sports-related concussion: is it still working?

Abstract In children, the importance of detecting deficits after mild traumatic brain injury (mTBI) or concussion has grown with the increasing popularity of leisure physical activities and contact sports. Whereas most postconcussive symptoms (PCS) are similar for children and adults, the breadth of consequences to children remains largely unknown. To investigate the effect of mTBI on brain function, we compared working memory performance and related brain activity using blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) in 15 concussed youths and 15 healthy age-matched control subjects. Neuropsychological tests, self-perceived PCS, and levels of anxiety and depression were also assessed. Our results showed that, behaviorally, concussed youths had significantly worse performances on the working memory tasks, as well as on the Rey figure delayed recall and verbal fluency. fMRI results revealed that, compared to healthy children, concussed youths had significantly reduced task-related activity in bilateral dorsolateral prefrontal cortex, left premotor cortex, supplementary motor area, and left superior parietal lobule during performance of verbal and nonverbal working memory tasks. Additionally, concussed youths also showed less activation than healthy controls in the dorsal anterior cingulate cortex, left thalamus, and left caudate nucleus during the nonverbal task. Regression analysis indicated that BOLD signal changes in bilateral dorsolateral prefrontal cortex were significantly correlated with performance such that greater activities in these regions, relative to the control condition, were associated with greater accuracy. Our findings confirmed functional alterations in brain activity after concussion in youths, a result similar to that observed in adults. However, significant differences were noted. In particular, the observation of reduced working memory accuracy suggests that youths may be unable to engage compensatory strategies to maintain cognitive performance after mTBI. This has significant implications for safe return to daily activities, including competitive sport.

Improving client-centered brain injury rehabilitation through research-based theater.

Traumatic brain injury often results in physical, behavioral, and cognitive impairments perceived by health care practitioners to limit or exclude clients' full participation in treatment decision making. We used qualitative methods to evaluate the short- and long-term impact of "After the Crash: A Play About Brain Injury," a research-based drama designed to teach client-centered care principles to brain injury rehabilitation staff. We conducted interviews and observations with staff of two inpatient neurorehabilitation units in Ontario, Canada. Findings demonstrate the effectiveness of the play in influencing practice through the avoidance of medical jargon to improve clients' understanding and participation in treatment; newfound appreciation for clients' needs for emotional expression and sexual intimacy; increased involvement of family caregivers; and avoidance of staff discussions as if clients were unaware. These findings suggest that research-based drama can effect reflexivity, empathy, and practice change to facilitate a client-centered culture of practice in brain injury rehabilitation.

Brain injury from a first nations' perspective: teachings from elders and traditional healers.

BACKGROUND: There is a lack of knowledge about how cultural ideas affect First Nations peoples' perception of rehabilitation needs and the ability to access services. PURPOSE: The study explored the perceptions of treating and healing brain injury from First Nations elders and traditional healers in the communities served by Wassay-Gezhig-Na-Nahn-Dah-We-lgamig (Kenora Area Health Access Centre). METHODS: A participatory action approach was used, leading to a focus group with elders and traditional healers. Findings, established through a framework analysis method, were member checked prior to dissemination. FINDINGS: Four themes arose from the data: pervasiveness of spirituality, "fixing" illness or injury versus living with wellness, working together in treating brain injury, and financial support needed for traditional healing. IMPLICATIONS: Funding is required for traditional healing services to provide culturallysafe and responsive occupational therapy services to First Nations individuals with brain injury.

Neural correlates of recognition memory for emotional faces and scenes.

We examined the influence of emotional valence and type of item to be remembered on brain activity during recognition, using faces and scenes. We used multivariate analyses of event-related fMRI data to identify whole-brain patterns, or networks of activity. Participants demonstrated better recognition for scenes vs faces and for negative vs neutral and positive items. Activity was increased in extrastriate cortex and inferior frontal gyri for emotional scenes, relative to neutral scenes and all face types. Increased activity in these regions also was seen for negative faces relative to positive faces. Correct recognition of negative faces and scenes (hits vs correct rejections) was associated with increased activity in amygdala, hippocampus, extrastriate, frontal and parietal cortices. Activity specific to correctly recognized emotional faces, but not scenes, was found in sensorimotor areas and rostral prefrontal cortex. These results suggest that emotional valence and type of visual stimulus both modulate brain activity at recognition, and influence multiple networks mediating visual, memory and emotion processing. The contextual information in emotional scenes may facilitate memory via additional visual processing, whereas memory for emotional faces may rely more on cognitive control mediated by rostrolateral prefrontal regions.

Sports-related mild traumatic brain injury in female youths.

Sports-related concussion or mild-traumatic brain injury (mTBI) is common in children who participate in organised sports. We describe two case studies involving 14-year-old girls who each sustained a mTBI during ice hockey competition. Neurocognitive functioning post-injury is compared to baseline pre-injury assessment on the same measures. Results from Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), Conners' Continuous Performance Test II (CPT-II) and the Attention Network Test (ANT) revealed decreased performance in attention, memory functioning and reaction time. Furthermore, some measures had not returned to baseline at midseason testing sessions approximately 30-40 days post-injury. The results are discussed with respect to the difference in recovery profiles and the need for thorough and ongoing evaluation following mTBI in the paediatric population, and for girls in particular.

Rehabilitation challenges for Aboriginal clients recovering from brain injury: a qualitative study engaging health care practitioners.

PRIMARY OBJECTIVE: To explore the experiences of health care practitioners working with Aboriginal clients recovering from acquired brain injury (ABI). RESEARCH DESIGN: Participatory research design using qualitative methods. METHODS: Fourteen in-depth, semi-structured interviews were conducted. The Framework Method of analysis was used to uncover emerging themes. FINDINGS: Five main categories emerged: practitioners' experience with brain injury, practitioners' experience with Aboriginal clients, specialized needs of Aboriginal clients recovering from brain injury, culturally sensitive care and traditional healing methods. These categories were then further divided into emergent themes and sub-themes where applicable, with particular emphasis on the specialized needs of Aboriginal clients. DISCUSSION: Each emergent theme highlighted key challenges experienced by Aboriginal peoples recovering from ABI. A key challenge was that protocols for rehabilitation and discharge planning are often lacking for clients living on reserves or in remote communities. Other challenges included lack of social support; difficulty of travel and socio-cultural factors associated with post-acute care; and concurrent disorders. CONCLUSIONS: Results suggest that developing reasonable protocols for discharge planning of Aboriginal clients living on reserves and/or remote communities should be considered a priority.

After the crash: research-based theater for knowledge transfer.

INTRODUCTION: The aim of this project was to develop and evaluate a research-based dramatic production for the purpose of transferring knowledge about traumatic brain injury (TBI) to health care professionals, managers, and decision makers. METHODS: Using results drawn from six focus group discussions with key stakeholders (consumers, informal caregivers, and health care practitioners experienced in the field of TBI) and relevant scientific literature, a 50-minute play was produced for the purpose of conveying the experiences of TBI survivors, informal care providers, and health practitioners and best practice for TBI care. A self-administered postperformance survey was distributed to audience members at the end of four performances in Ontario, Canada, to evaluate the play's efficacy. Two hundred ninety-one questionnaires were completed. The questionnaire had five questions scored on a 5-item Likert scale with space for open-ended comments. RESULTS: Consistently high mean scores from the questionnaires indicate that theater is a highly efficacious and engaging method of knowledge transfer, particularly for complex material that deals with human emotion and interpersonal relationships. DISCUSSION: Responses supported the effectiveness of drama as a knowledge translation strategy and identified its potential to impact practice positively.

Age-related differences in brain activity underlying identification of emotional expressions in faces.

We used fMRI to explore brain activity in young and old adults, while they viewed and labeled faces expressing different emotions as well as neutral expressions. Older adults had significantly greater difficulty identifying expressions of sadness, anger and disgust than young adults. Both groups performed at ceiling for happy expressions. The functional neuroimaging data revealed that both young and old adults recruited a pattern of activity that distinguished happy expressions from all other expressions, but the patterns were age-specific. Older adults showed increased activity in ventromedial prefrontal cortex, lingual gyrus and premotor cortex for happy expressions, whereas younger adults recruited a more widely distributed set of regions including the amgydala, ventromedial prefrontal cortex, lateral prefrontal regions and bilateral inferior parietal and superior temporal areas. Conversely, younger adults showed more activity in the dorsal anterior cingulate for other types of expressions, and older adults had more activity in dorsal cingulate, as well as middle and inferior frontal gyri, somatosensory cortex, insula and middle temporal regions. These results support previous research demonstrating age differences in brain activity during emotional processing, and suggest possible age-related differences in cognitive strategy during identification of happy faces, despite no effect of age on this ability.

Age effects on social cognition: faces tell a different story.

The authors administered social cognition tasks to younger and older adults to investigate age-related differences in social and emotional processing. Although slower, older adults were as accurate as younger adults in identifying the emotional valence (i.e., positive, negative, or neutral) of facial expressions. However, the age difference in reaction time was largest for negative faces. Older adults were significantly less accurate at identifying specific facial expressions of fear and sadness. No age differences specific to social function were found on tasks of self-reference, identifying emotional words, or theory of mind. Performance on the social tasks in older adults was independent of performance on general cognitive tasks (e.g., working memory) but was related to personality traits and emotional awareness. Older adults also showed more intercorrelations among the social tasks than did the younger adults. These findings suggest that age differences in social cognition are limited to the processing of facial emotion. Nevertheless, with age there appears to be increasing reliance on a common resource to perform social tasks, but one that is not shared with other cognitive domains.

Distributed self in episodic memory: neural correlates of successful retrieval of self-encoded positive and negative personality traits.

Words processed with reference to the self are generally better remembered than words processed in semantic terms. An account of this phenomenon, labeled the Self Reference Effect (SRE), is that the self promotes elaboration and organization of encoded information. Although a few neuroimaging studies associated self-referential encoding with activations of the medial prefrontal cortex, no previous study has investigated the neural correlates of remembering emotional words encoded in an SRE paradigm. The main goal of this study was to define with fMRI the neural correlates of the successful retrieval of negative and positive personality traits encoded in a self-referential mode. Functional MRI scans were acquired for 11 subjects as they recognized positive and negative emotional personality traits adjectives encoded in a self-referential condition, a semantic condition and in a phonemic condition. The correct recognition of self-encoded personality traits engaged dorso-medial prefrontal cortex and lateral prefrontal regions, premotor cortex, parietal and occipital cortex, caudate and cerebellum. The specific recognition of self-encoded negative personality traits involved greater neural activation in the right extra-striate region than the recognition of positive personality traits. Our fMRI findings suggest that specific processes may operate at both encoding and retrieval to subserve the SRE. Unlike self-encoding, the retrieval of personality traits is modulated by the valence of the stimuli with greater activation for negative words. Our results indicate that personally relevant words may signal important emotional clues and support the notion of a widely distributed set of brain regions involved in maintaining the concepts of self.

Personality influences limbic-cortical interactions during sad mood induction.

The current study examined limbic-cortical activation under transient emotional stress as a function of personality style. A ventral cingulate (Cg25)-centred limbic-cortical network was identified using positron emission tomography (PET) measures of regional cerebral blood flow (rCBF) during a sad mood challenge that demonstrated differences for individuals selected for specific patterns of Negative and Positive emotional traits, indexed by the NEO Personality Inventory-Revised. Healthy subjects scoring both low on the dispositional Depression facet of Neuroticism (N3) and high on the Positive Emotions facet of Extraversion (E6) were compared to those scoring high on the Depression facet (N3) and low on Positive Emotions (E6), a combination of traits previously linked to normal variations in mood reactivity. Scan analyses were designed to further characterize known variations in Cg25 activity previously reported in studies of negative mood in both healthy subjects and depressed patients. A multivariate technique, partial least squares (PLS) demonstrated a divergent Cg25-mediated network that differentiated temperamentally negative (NAS) from temperamentally positive (PAS) subjects providing a potential neural link between these specific combinations of trait affective styles and vulnerability to depression.

In search of the emotional self: an fMRI study using positive and negative emotional words.

OBJECTIVE: The authors used functional magnetic resonance imaging (fMRI) to define the neural regions mediating self-referential processing of emotional stimuli and to explore how these regions are influenced by the emotional valence of the stimulus. METHOD: Ten healthy subjects were presented with words describing positive and negative personality traits during fMRI scanning in three different conditions. In the self-referential processing condition, subjects judged whether they thought each trait described them. In the other-referential processing condition, subjects judged whether the stimulus described a generally desirable trait. In the letter-recognition control condition, subjects indicated whether the word contained a specific target letter. RESULTS: The self-referential condition induced bilateral activation in the dorsomedial prefrontal cortex, whereas the other-referential condition induced activation in lateral prefrontal areas. Activation in the right dorsomedial prefrontal cortex was unique to the self-referential condition regardless of the valence of the words, although positive words produced a more robust activation than did negative words. In the self-referential condition, differences between the processing of positive and negative words were seen in regions outside the medial frontal cortex, with reductions in the insula, temporal and occipital regions, and inferior parietal regions associated with negative words. CONCLUSIONS: A widely distributed network of brain areas contributes to emotional processing. Among these regions, the right dorsomedial prefrontal cortex is one main area mediating self-reference. By providing a personal perspective in the evaluation of emotional stimuli, the right dorsomedial prefrontal cortex may mediate cognitive processes, such as those involved in psychotherapy, that guide self-regulation of emotional experience.

An fMRI study investigating cognitive modulation of brain regions associated with emotional processing of visual stimuli.

Brain regions modulated by cognitive tasks during emotional processing were investigated using fMRI. Participants performed indirect and direct emotional processing tasks on positive and negative faces and pictures. We used a multivariate technique, partial least squares (PLS) to determine spatially distributed patterns of brain activity associated with different tasks and stimulus conditions, as well as the interaction between the two. The pattern of brain activity accounting for the most task-related covariance represented a task x stimulus interaction and distinguished indirect processing of pictures and direct processing of faces from direct processing of pictures and indirect processing of faces. The latter two conditions were characterised by limbic (e.g. amygdala, insula, thalamus) and temporal lobe activity, in addition to greater activity in the ventral prefrontal cortex. Indirect and direct processing of pictures and faces, respectively, were represented by more dorsal prefrontal and parietal activity. These findings indicate that brain activity during processing of emotional content is critically dependent on both the type of stimulus and processing task. In addition, these results support the idea that the pattern of activity in the emotional network can be influenced in a 'top-down' fashion via cognitive factors such as attentional control, and as such, have important clinical implications for emotional disorders, such as depression and anxiety.

Evidence from functional neuroimaging of a compensatory prefrontal network in Alzheimer's disease.

Previous experiments have found that individuals with Alzheimer's disease (AD) show increased activity in prefrontal regions compared with healthy age-matched controls during cognitive tasks. This has been interpreted as compensatory reallocation of cognitive resources, but direct evidence for a facilitating effect on performance has been lacking. To address this we measured neural activity during semantic and episodic memory tasks in mildly demented AD patients and healthy elderly controls. Controls recruited a left hemisphere network of regions, including prefrontal and temporal cortices in both the semantic and episodic tasks. Patients engaged a unique network involving bilateral dorsolateral prefrontal and posterior cortices. Critically, activity in this network of regions was correlated with better performance on both the semantic and episodic tasks in the patients. This provides the most direct evidence to date that AD patients can use additional neural resources in prefrontal cortex, presumably those mediating executive functions, to compensate for losses attributable to the degenerative process of the disease.

Studies of altered social cognition in neuropsychiatric disorders using functional neuroimaging.

In this paper, we review studies using functional neuroimaging to examine cognition in neuropsychiatric disorders. The focus is on social cognition, which is a topic that has received increasing attention over the past few years. A network of brain regions is proposed for social cognition that includes regions involved in processes relevant to social functioning (for example, self reference and emotion). We discuss the alterations of activity in these areas in patients with autism, depression, schizophrenia, and posttraumatic stress disorders in relation to deficits in social behaviour and symptoms. The evidence to date suggests that there may be some specificity of the brain regions involved in these 4 disorders, but all are associated with dysfunction in the amygdala and dorsal cingulate gyrus. Although there is much work remaining in this area, we are beginning to understand the complex interactions of brain function and behaviour that lead to disruptions of social abilities.