The long-term effects of traumatic brain injury on the coordinative function of the central executive

Intramuscular insulin-like growth factor-1 gene therapy modulates reactive microglia after traumatic brain injury

Reactive gliosis is a key feature and an important pathophysiological mechanism underlying chronic neurodegeneration following traumatic brain injury (TBI). In this study, we have explored the effects of intramuscular IGF-1 gene therapy on reactive gliosis and functional outcome after an injury of the cerebral cortex. Young adult male rats were intramuscularly injected with a recombinant adenoviral construct harboring the cDNA of human IGF-1 (RAd-IGF1), with a control vector expressing green fluorescent protein (RAd-GFP) or PBS as control. Three weeks after the intramuscular injections of adenoviral vectors, animals were subjected to a unilateral penetrating brain injury. The data revealed that RAd-IGF1 gene therapy significantly increased serum IGF1 levels and improved working memory performance after one week of TBI as compared to PBS or RAd-GFP lesioned animals. At the same time, when we analyzed the effects of therapy on glial scar formation, the treatment with RAd-IGF1 did not modify the number of glial fibrillary acidic protein (GFAP) positive cells, but we observed a decrease in vimentin immunoreactive astrocytes at 7 days post-lesion in the injured hemisphere compared to RAd-GFP group. Moreover, IGF-1 gene therapy reduced the number of Iba1+ cells with reactive phenotype and the number of MHCII + cells in the injured hemisphere. These results suggest that intramuscular IGF-1 gene therapy may represent a new approach to prevent traumatic brain injury outcomes in rats.

Effects of spatial working memory in balance during dual tasking in traumatic brain injury and healthy controls

OBJECTIVES

The aim of this research was to assess cognitive-motor interactions though dual tasks of working memory in patients with traumatic brain injury (TBI) and control subjects. Methods: Twenty patients with chronic TBI with good functional level and 19 matched healthy controls performed dual working memory tasks (1-back numeric and 1-back spatial (S)) while sitting, standing, and walking. The center of pressure (COP) displacement amplitude, cadence, and error percentage (PER) were recorded as dependent variables. Results: The results revealed main effects of Group (TBI, controls) (p = .011) and Task factors (Single, Dual Standing 1-back, Dual Standing 1-back (S); p = .0001) for the COP. Patients showed greater displacement than controls (p = .011), and an analysis of the Task factor showed a minor displacement for the dual 1-back (S) task compared with the 1-back and single task (p = .002 and p = .001, respectively). Conclusions: Postural control during both standing and walking improved during performance of the spatial working memory task. In the dual task, both patients and controls showed a postural prioritization as an adaptive response to the increase in cognitive demand.

Posttraumatic Stress Symptoms and Disorders in Children and Adolescents with Chronic Physical Illnesses: a Meta-Analysis

The aim of the present meta-analysis was to compare levels of posttraumatic stress symptoms (PTSS) and the prevalence of posttraumatic stress disorders (PTSD) in individuals with and without pediatric chronic physical illnesses, and to analyze correlates of these symptoms. In total, 150 studies were identified that provided relevant data. On average, 11.5% of the participants with pediatric chronic physical illnesses met the criteria of PTSD (Odds Ratio 2.70). PTSS were also more common in this group than in control groups without chronic physical illnesses. While the PTSS levels did not differ across physical diseases, we found positive associations of PTSS with illness severity and duration/intensity of treatment, as well as negative associations with duration of illness, time since last treatment, treatment adherence, and family functioning. We conclude that individuals with pediatric chronic physical illnesses who experienced traumatic events should be screened for PTSS and receive psychological interventions when needed.

Considerations for developing chronic care system for traumatic brain injury based on comparisons of cancer survivorship and diabetes management care

Experts in traumatic brain injury (TBI) rehabilitation recently proposed the framing of TBI as a chronic disease rather than a discrete event. Within the framework of the Chronic Care Model (CCM), a systematic comparison of three diseases - cancer survivorship, diabetes management and TBI chronic care - was conducted regarding chronic needs and the management of those needs. In addition, comparisons of these conditions require comparative evaluations of disease management characteristics and the survivor concept. The analysis found diabetes is more established within the CCM, where care is integrated across specialists and primary care providers. No single comparison provides a full analogue for understanding the chronic care health delivery system for TBI, indicating the need for a separate model to address needs and resources for TBI survivors. The findings from this research can provide practitioners with a context to develop a robust continued care health system for TBI. Practitioner Summary: We examine development of a chronic care system for traumatic brain injury. We conducted a systematic comparison of Chronic Care Model elements of decision and information support. Development of capabilities using a benchmark of diabetes care, with additional insights from cancer care, provides insights for implementing TBI chronic care systems.

Language control in bilingual adults with and without history of mild traumatic brain injury

Adults with a history of traumatic brain injury often show deficits in executive functioning (EF), including the ability to inhibit, switch, and attend to tasks. These abilities are critical for language processing in bilinguals. This study examined the effect of mild traumatic brain injury (mTBI) on EF and language processing in bilinguals using behavioral and eye-tracking measures. Twenty-two bilinguals with a history of mTBI and twenty healthy control bilinguals were administered executive function and language processing tasks. Bilinguals with a history of mTBI showed deficits in specific EFs and had higher rates of language processing errors than healthy control bilinguals. Additionally, individuals with a history of mTBI have different patterns of eye movements during reading than healthy control bilinguals. These data suggest that language processing deficits are related to underlying EF abilities. The findings provide important information regarding specific EF and language control deficits in bilinguals with a history mTBI.

Frequência de déficits neuropsicológicos após traumatismo cranioencefálico

O traumatismo cranioencefálico (TCE) pode acarretar mudanças no cotidiano e prejuízos social laboral comunicativo e cognitivo (dificuldades atencionais mnemônicas e executivas). Este estudo buscou caracterizar a ocorrência de déficits neuropsicológicos após o TCE em uma amostra de adultos e verificar se há impacto do nível de severidade do trauma no desempenho cognitivo dos pacientes. Participaram 96 adultos divididos em dois grupos: TCE leve (n=39) e grave (n=57). A gravidade do trauma foi classificada pela Escala de Coma de Glasgow pela duração da perda de consciência. ou pela amnésia pós-traumática. Não houve diferença nas variáveis sociodemográficas idade e escolaridade entre os grupos. Para a comparação entre grupos quanto a ocorrência de déficits neuropsicológicos. utilizou-se o Qui-quadrado. Tarefas verbais e visuoespaciais de funções executivas habilidades linguísticas. mnemônicas verbais compuseram uma bateria neuropsicológica flexível.Os pacientes com TCE leve tiveram menos déficits comparados aos com TCE grave (erros e categorias completadas do Wisconsin Teste de Classificação de Cartas; erros da parte B do Teste Hayling; e na interferência pró e retroativa do teste de aprendizagem verbal de Rey). A severidade do trauma parece diferenciar indivíduos no desempenho de memória episódica no contexto de maior sobrecarga de informações novas e no controle da interferência entre memórias; o mesmo se aplica às funções de flexibilidade e inibição. Fazse necessário um maior investimento em ações de políticas públicas de saúde priorizando intervenção neurognitiva remediativa e métodos de prevenção para acidentes relacionados a lesões traumáticas com alta ocorrência de sequelas.

Executive function impairments in depression and bipolar disorder: association with functional impairment and quality of life

BACKGROUND

The neuropsychological correlates of major depressive (MDD) and bipolar disorder (BD), and their association with quality of life (QOL) and functioning, have not been sufficiently studied in the literature. The present study aimed to compare executive functions, attention, processing speed, QOL and disability between patients with BD type I, BD type II, MDD and healthy controls.

METHOD

205 participants (n=37 BDI, 81% female; n=35 BDII, 80% female; n=45 MDD, 69% female; n=89C, 46% female) aged between 18 and 67 years were administered an extensive neurocognitive battery consisting of widely used standardized measures such as the Trail Making Test, the Stroop Color-Word Test and a modified version of the Wisconsin Card Sorting Task. Z-scores were compared between groups by ANCOVA. The prevalence of impairments on each measure (Z-score<1.5) was compared between groups using chi-square tests. The associations between cognition, quality of life and functioning were evaluated through correlational analysis.

RESULTS

Patients with MDD showed poor selective and sustained attention, and exhibited impairments in timed tasks, suggesting low efficiency of executive processing. Patients with BDI displayed more widespread cognitive impairment than the remaining groups, and performed worse than subjects with MDD on measures of sustained attention and inhibitory control. Decision-making ability and attentional control were able to distinguish between patients with BDI and BDII. QOL and disability were most impaired in patients with BDI, and more closely associated with cognitive impairment than in the remaining groups.

LIMITATIONS

No control of pharmacological variables, clinical or demographic characteristics.

CONCLUSIONS

Our results provide important information regarding the nature and severity of the cognitive alterations associated with different mood disorders, and may contribute to the diagnosis, rehabilitation and treatment of these conditions.

The Predictive Impact of Biological and Sociocultural Factors on Executive Processing: The Role of Age, Education, and Frequency of Reading and Writing Habits

Although the impact of education and age on executive functions (EF) has been widely studied, the influence of daily cognitive stimulation on EF has not been sufficiently investigated. Therefore, the aim of the present study was to evaluate whether the age, education, and frequency of reading and writing habits (FRWH) of healthy adults could predict their performance on measures of inhibition and cognitive flexibility. Inhibition speed, inhibitory control, and set shifting were assessed using speed, accuracy, and discrepancy scores on the Trail-Making Test (TMT) and Hayling Test. Demographic characteristics and the FRWH were assessed using specialized questionnaires. Regression analyses showed that age and the FRWH predicted speed and accuracy on the TMT. The FRWH predicted both speed and accuracy on the Hayling Test, for which speed and accuracy scores were also partly explained by age and education, respectively. Surprisingly, only the FRWH was associated with Hayling Test discrepancy scores, considered one of the purest EF measures. This highlights the importance of regular cognitive stimulation over the number of years of formal education on EF tasks. Further studies are required to investigate the role of the FRWH so as to better comprehend its relationship with EF and general cognition.

Evidence of cognitive decline in older adults after remote traumatic brain injury: an exploratory study

Separate bodies of literature indicate that a history of a traumatic brain injury (TBI) and natural aging may result in overlapping cognitive profiles, yet little is known about their combined effect. We predicted that a remote TBI would compound normal age-related cognitive decline, particularly affecting executive function. Neuropsychological task performance was compared between a group of older adults who sustained a TBI in their distant past (N = 9) and a group of older adults with no history of head injury (N = 15). While all participants scored in the normal range on the Mini-Mental State Examination, the TBI group scored lower than the non-TBI group. Also, in line with predictions, the TBI group made more errors on measures of executive functioning compared to the non-TBI group (the Trail Making B test and the incongruent condition of the Stroop Test), but performed similarly on all tasks with little executive requirements. Findings from this exploratory study indicate that a past TBI may put older adults at a higher risk for exacerbated age-related cognitive decline compared to older adults with no history of TBI.

Negative neuroplasticity in chronic traumatic brain injury and implications for neurorehabilitation

Based on growing findings of brain volume loss and deleterious white matter alterations during the chronic stages of injury, researchers posit that moderate-severe traumatic brain injury (TBI) may act to “age” the brain by reducing reserve capacity and inducing neurodegeneration. Evidence that these changes correlate with poorer cognitive and functional outcomes corroborates this progressive characterization of chronic TBI. Borrowing from a framework developed to explain cognitive aging (Mahncke et al., Progress in Brain Research, 157, 81–109, 2006a; Mahncke et al., Proceedings of the National Academy of Sciences of the United States of America, 103(33), 12523–12528, 2006b), we suggest here that environmental factors (specifically environmental impoverishment and cognitive disuse) contribute to a downward spiral of negative neuroplastic change that may modulate the brain changes described above. In this context, we review new literature supporting the original aging framework, and its extrapolation to chronic TBI. We conclude that negative neuroplasticity may be one of the mechanisms underlying cognitive and neural decline in chronic TBI, but that there are a number of points of intervention that would permit mitigation of this decline and better long-term clinical outcomes.

Pragmatic and executive functions in traumatic brain injury and right brain damage: An exploratory comparative study

OBJECTIVE

To describe the frequency of pragmatic and executive deficits in right brain damaged (RBD) and in traumatic brain injury (TBI) patients, and to verify possible dissociations between pragmatic and executive functions in these two groups.

METHODS

The sample comprised 7 cases of TBI and 7 cases of RBD. All participants were assessed by means of tasks from the Montreal Communication Evaluation Battery and executive functions tests including the Trail Making Test, Hayling Test, Wisconsin Card Sorting Test, semantic and phonemic verbal fluency tasks, and working memory tasks from the Brazilian Brief Neuropsychological Assessment Battery NEUPSILIN. Z-score was calculated and a descriptive analysis of frequency of deficits (Z< -1.5) was carried out.

RESULTS

RBD patients presented with deficits predominantly on conversational and narrative discursive tasks, while TBI patients showed a wider spread pattern of pragmatic deficits. Regarding EF, RBD deficits included predominantly working memory and verbal initiation impairment. On the other hand, TBI individuals again exhibited a general profile of executive dysfunction, affecting mainly working memory, initiation, inhibition, planning and switching. Pragmatic and executive deficits were generally associated upon comparisons of RBD patients and TBI cases, except for two simple dissociations: two post-TBI cases showed executive deficits in the absence of pragmatic deficits.

DISCUSSION

Pragmatic and executive deficits can be very frequent following TBI or vascular RBD. There seems to be an association between these abilities, indicating that although they can co-occur, a cause-consequence relationship cannot be the only hypothesis.