Working memory brain activation following severe traumatic brain injury

Functional magnetic resonance imaging (fMRI) has shown that brain activation during performance of working memory (WM) tasks under high memory loads is altered in adults with severe traumatic brain injury (TBI) relative to uninjured subjects (Perlstein et al., 2004; Scheibel et al., 2003). Our study attempted to equate TBI patients and orthopedically injured (OI) subjects on performance of an N-Back task that used faces as stimuli. To minimize confusion in TBI patients that was revealed in pilot work, we presented the memory conditions in two separate tasks, 0- versus 1-back and 0- versus 2-back. In the 0- versus 1-back task, OI subjects activated bilateral frontal areas more extensively than TBI patients, and TBI patients activated posterior regions more extensively than OI subjects. In the 0- versus 2-back task, there were no significant differences between the groups. Analysis of changes in activation over time on 1-back disclosed that OI subjects had decreases in bilateral anterior and posterior regions, while TBI patients showed activation increases in those and other areas over time. In the 2-back condition, both groups showed decreases over time in fusiform and parahippocampal gyri, although the OI group also showed increases over time in frontal, parietal, and temporal areas not seen in the TBI patients. The greatest group differences were found in the 1-back condition, which places low demand on WM. Although the extent of activation in the 2-back condition did not differ between the two groups, deactivation in the 2-back condition was seen in the OI patients only, and both groups' patterns of activation over time varied, suggesting a dissociation between the TBI and OI patients in recruitment of neural areas mediating WM.     

Caregiver reports of common symptoms in children following a traumatic brain injury

This study describes the common symptoms in children and adolescents following a traumatic brain injury (TBI) as reported by their primary caregivers. Utilizing data from a large-scale state demonstration project, 681 children who had sustained a TBI were ascertained from both Hospital Emergency Departments (n = 409) and Pediatric Inpatient settings (n = 272). The sample ranged in age from infancy to 18 years, was largely male (59.7%), and had equal numbers of Caucasian and minority patients. Most of the participants experienced a mild TBI (83%), with about 5.1% being moderate and 12% severe. Caregivers described the presence of current symptoms (neurological, neurocognitive, behavioral, school problems) using a series of dichotomous questions regarding their child via a structured telephone interview at 1, 4, and 10 months post-injury. Inpatient children were described as manifesting more symptoms at each of the follow-up time points than their ED counterparts. At 1 month inpatients were described as having more symptoms across all 4 domains. At 4 and 10 months, the inpatients were described as having more neurocognitive symptoms and as not returning to school on a full-time basis, with behavior problems approaching significance at the 10-month point. A large number of individuals from both groups also reported persistent symptoms 10 months post-injury including headaches, attention and memory problems, low frustration tolerance, sleep problems, personality changes, and new school problems. Practical implications of these findings for the ongoing management of these children are discussed.     

Family impact and influence following severe traumatic brain injury

Negotiating is the core variable or central concern of families who have a close relative in a state of post-comatose unawareness or minimal responsiveness following a severe traumatic brain injury. Family members negotiate with each other, with members of the health care team, and with others such as insurance agents, case managers, and representatives of the justice system on behalf of the injured individual. Family members also negotiate the intricacies of the health care system. These are the findings of a 16-month grounded theory study conducted on two acute neurosurgical units in Toronto, with 25 family members from 11 families who had a close family member who suffered a severe traumatic brain injury and who was in a state of post-comatose unawareness or minimal responsiveness. An extensive review of the scholarly literature related to family research methodology and family research related to families following the brain injury of a family member is also provided in this paper.     

Cerebrovascular response in children following severe traumatic brain injury

Objective  

To describe the pathophysiologic response in cerebral blood flow (CBF) and autoregulation after severe traumatic brain injury (TBI), Glasgow Coma Score (GCS) ≤8 on admission, in children, defining a baseline for future studies.     

Social recovery during the year following severe head injury.

A group of 54 patients who had suffered severe closed head injury (PTA >24 hours) were followed from the time of their injury for a period of two years. Relatives were interviewed within the first four weeks to assess the patient's previous personality and social adjustment. Patients and relatives were then assessed personally six and 12 months later and by postal questionnaires after two years. Only six patients were still not back at work after two years but more had not resumed all their leisure activities. Family relationships appeared to have settled down again by this stage but social contacts were still less frequent. Personality changes were associated with prior family relationships, cognitive changes with diminished social contacts whilst premorbid personality and physical deficits were associated with time taken to return to work.     

Endocrine function in children acutely following severe traumatic brain injury

Purpose  

Despite the prevalence of frontal injury following traumatic brain injury (TBI) in adults and children with potentially concomitant hypothalamic and pituitary involvement, endocrine dysfunction acutely following TBI has not been well studied in children.     

Predictions of episodic memory following moderate to severe traumatic brain injury during inpatient rehabilitation

We examined memory self-awareness and memory self-monitoring abilities during inpatient rehabilitation in participants with moderate to severe traumatic brain injury (TBI). A total of 29 participants with moderate to severe TBI and 29 controls matched on age, gender, and education completed a performance prediction paradigm. To assess memory self-awareness, participants predicted the amount of information they would remember before completing list-learning tasks and visual-spatial memory tasks. Memory self-monitoring was assessed by participants' ability to increase accuracy of their predictions after experience with the tests. Although the TBI participants performed more poorly than controls on both episodic memory tasks, no significant group differences emerged in memory self-awareness or memory self-monitoring. The TBI participants predicted that their memory performances would be poorer than that of controls, accurately adjusted their predictions in accordance with the demands of the tasks, and successfully modified their predictions following experience with the tasks. The results indicate that moderate to severe TBI individuals in the early stages of recovery can competently assess the demands of externally driven metamemorial situations and utilize experience with task to accurately update their knowledge of memory abilities.     

Irritability following traumatic brain injury

This study was undertaken to identify the clinical and pathoanatomical correlates of irritability in patients with closed head injuries. A consecutive series of 66 patients was assessed in hospital and at 3, 6, 9, and 12-month follow-ups. Patients fulfilling criteria for irritability were divided into 2 groups based on the immediate or delayed onset of their irritability and compared with patients without irritability for background characteristics, impairment variables, and lesion characteristics. There were 12 patients (18.2%) with acute onset irritability and 10 (15.1%) with delayed onset irritability. Acute onset irritability patients had a higher frequency of left cortical lesions. Delayed onset irritability patients showed a strong association with poor social functioning and greater impairment in activities of daily living. The findings suggest that post-brain injury irritability may have different causes and treatment in the acute and chronic stages.     

Psychosis following traumatic brain injury

Psychosis is a relatively infrequent but potentially serious and debilitating consequence of traumatic brain injury (TBI), and one about which there is considerable scientific uncertainty and disagreement. There are several substantial clinical, epidemiological, and neurobiological differences between the post-traumatic psychoses and the primary psychotic disorders. The recognition of these differences may facilitate identification and treatment of patients whose psychosis is most appropriately regarded as post-traumatic. In the service of assisting psychiatrists and other mental health clinicians in the diagnosis and treatment of persons with post-traumatic psychoses, this article will review post-traumatic psychosis, including definitions relevant to describing the clinical syndrome, as well as epidemiologic, neurobiological, and neurogenetic factors attendant to it. An approach to evaluation and treatment will then be offered, emphasizing identification of the syndrome of post-traumatic psychosis, consideration of the differential diagnosis of this condition, and careful selection and administration of treatment interventions.     

Psychosis following traumatic brain injury

Psychosis is a relatively infrequent but potentially serious and debilitating consequence of traumatic brain injury (TBI), and one about which there is considerable scientific uncertainty and disagreement. There are several substantial clinical, epidemiological, and neurobiological differences between the post-traumatic psychoses and the primary psychotic disorders. The recognition of these differences may facilitate identification and treatment of patients whose psychosis is most appropriately regarded as post-traumatic. In the service of assisting psychiatrists and other mental health clinicians in the diagnosis and treatment of persons with post-traumatic psychoses, this article will review post-traumatic psychosis, including definitions relevant to describing the clinical syndrome, as well as epidemiologic, neurobiological, and neurogenetic factors attendant to it. An approach to evaluation and treatment will then be offered, emphasizing identification of the syndrome of post-traumatic psychosis, consideration of the differential diagnosis of this condition, and careful selection and administration of treatment interventions.     

The covert orienting of visual attention following severe traumatic brain injury

Attentional problems have frequently been identified following traumatic brain injuries (TBIs) using both clinical assessments and self-report measures. Unfortunately, most measures of attention do not enable us to determine the underlying basis of these attentional deficits. One exception is Posner's Covert Orienting of Attention Task (COAT), which is designed to identify some of the fundamental mental operations underlying attention. This study sought to determine whether the COAT task could identify discrete attentional deficits following TBI beyond those caused by reduced speed of information processing. Thirty five patients who had sustained a severe TBI were compared to 35 age-matched controls. Results revealed that, although the reaction times of the patients with TBI were significantly slower than the controls, there were no differences between the two groups in terms of their ability to disengage, move, and engage their attention. The introduction of a secondary (language) task produced no significant difference between the two groups on the COAT task. However, there was a significant difference between the two groups on the language-based task, suggesting a deficit in auditory-verbal attention under dual task conditions.     

Quality-of-life: Child and parent perspectives following severe traumatic brain injury

Purpose: Traumatic brain injury (TBI) can produce temporary or permanent impairment. Quality-of-life (QoL) after TBI has been well studied in adults, but less so in children. The aim of this study was to assess the QoL of children with TBI and compare the findings with the evaluations of parents and children without brain injury.

Methods: Participants were 23 children with TBI, mean age 11 years, who had been treated at the SARAH Network of Rehabilitation Hospitals. Participants were matched by age, sex, parents’ socio-cultural level and place of residence with 23 other children who had no history of brain injury. The instruments used were the SARAH QoL Questionnaire for Children and Adolescents, Wechsler Intelligence Scale for Children, the SARAH Physical-Functional Classification of the Child and Adolescent and a structured interview with parents.

Results: The results demonstrated that, in an average 4 years after the accident, all of the children with TBI were attending school and most could walk independently. The parents’ reports about post-TBI problems were marginally associated with the children's self-evaluations. The parents showed important concerns regarding their child across all dimensions of life.

Conclusions: Children with TBI report significantly reduced QoL compared to a control group in the physical, psychological, cognitive and total score dimensions. However, TBI children with average academic performance (65%) obtained the same QoL scores as the control group.     

Interpreting facial expression and communication competence following severe traumatic brain injury

Background: Facial expression is generally understood as playing a crucial role in communication, conveying both information and emotion. This study explored the nexus between the ability to interpret facial expression and communication competence for individuals with traumatic brain injury (TBI).

Aims: Three research questions were addressed. The first two questions involved a comparison of TBI and control participants on perceived communication competence, and ability to interpret facial expression. The third research question addressed whether a relationship exists between ability to interpret facial expression and perceived communication competence, in individuals with TBI.

Methods & Procedures: Participants included 12 individuals with severe TBI (PTA>7 days), and a group of matched controls. A measure of perceived communication competence (the La Trobe Communication Questionnaire, LCQ) and a measure related to the interpretation of facial expression (the Emotion Evaluation Test) were administered to TBI and control participants All participants nominated a “close‐other” who completed the close‐other form of the LCQ.

Outcomes & Results: Results revealed that TBI participants were perceived to have significantly more difficulties with communication than control participants (p = .002). Similarly, results also revealed that TBI participants had significantly more difficulty interpreting facial expression than control participants (p<.001). Pearson's Correlation Coefficient (r) calculations demonstrated a significant relationship between ability to interpret facial expression and close‐other perception of communication competence (r = .532).

Conclusions: Results are consistent with previous research, and suggest that ability to interpret facial expression is closely related to perceived communication competence, in individuals with TBI. This understanding has implications for rehabilitation and may inform the development of treatment strategies specifically targeting impairment in the ability to read facial expression.     

Dysautonomia after severe traumatic brain injury

Background: Dysautonomia after traumatic brain injury (TBI) is characterized by episodes of increased heart rate, respiratory rate, temperature, blood pressure, muscle tone, decorticate or decerebrate posturing, and profuse sweating. This study addresses the incidence of dysautonomia after severe TBI, the clinical variables that are associated with dysautonomia, and the functional outcome of patients with dysautonomia. Methods: A historic cohort study in patients with severe TBI [Glasgow Coma Scale (GCS) ≤ 8 on admission]. Results: Seventy‐six of 119 patients survived and were eligible for follow‐up. The incidence of dysautonomia was 11.8%. Episodes of dysautonomia were prevalent during a mean period of 20.1 days (range 3–68) and were often initiated by discomfort. Patients with dysautonomia showed significant longer periods of coma (24.78 vs. 7.99 days) and mechanical ventilation (22.67 vs. 7.21 days). Dysautonomia was associated with diffuse axonal injury (DAI) [relative risk (RR) 20.83, CI 4.92–83.33] and the development of spasticity (RR 16.94, CI 3.96–71.42). Patients with dysautonomia experienced more secondary complications. They tended to have poorer outcome. Conclusions: Dysautonomia occurs in approximately 10% of patients surviving severe TBI and is associated with DAI and the development of spasticity at follow‐up. The initiation of dysautonomia by discomfort supports the Excitatory: Inhibitory Ratio model as pathophysiological mechanism.     

Dysphagia in severe traumatic brain injury

Dysphagia, or swallowing difficulty, is a common problem following severe traumatic brain injury and is associated with an increased risk of malnutrition and pneumonia. Management of patients with dysphagia following head injury is complicated by the presence of cognitive, communication, and behavioral impairments. The purpose of this review article is to help physicians taking care of traumatic brain injury patients understand and manage dysphagia. The article reviews the history of the study of swallowing, stages of swallowing, impairments of swallowing, neural control of swallowing, and the evaluation of patients with swallowing difficulties and their management. In addition to the general principles of dysphagia management, this article covers the management of dysphagic patients with tracheostomy and their nutritional management.     

Assessing connectivity related injury burden in diffuse traumatic brain injury

Many of the clinical and behavioral manifestations of traumatic brain injury (TBI) are thought to arise from disruption to the structural network of the brain due to diffuse axonal injury (DAI). However, a principled way of summarizing diffuse connectivity alterations to quantify injury burden is lacking. In this study, we developed a connectome injury score, Disruption Index of the Structural Connectome (DISC), which summarizes the cumulative effects of TBI‐induced connectivity abnormalities across the entire brain. Forty patients with moderate‐to‐severe TBI examined at 3 months postinjury and 35 uninjured healthy controls underwent magnetic resonance imaging with diffusion tensor imaging, and completed behavioral assessment including global clinical outcome measures and neuropsychological tests. TBI patients were selected to maximize the likelihood of DAI in the absence of large focal brain lesions. We found that hub‐like regions, with high betweenness centrality, were most likely to be impaired as a result of diffuse TBI. Clustering of participants revealed a subgroup of TBI patients with similar connectivity abnormality profiles who exhibited relatively poor cognitive performance. Among TBI patients, DISC was significantly correlated with post‐traumatic amnesia, verbal learning, executive function, and processing speed. Our experiments jointly demonstrated that assessing structural connectivity alterations may be useful in development of patient‐oriented diagnostic and prognostic tools. Hum Brain Mapp 38:2913–2922, 2017. © 2017 Wiley Periodicals, Inc.