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Background: Diffuse axonal injury occurs with high acceleration and deceleration forces in traumatic brain injury (TBI). This lesion leads to disarrangement of the neuronal network, which can result in some degree of deficiency. The Extended Glasgow Outcome Scale (GOS-E) is the primary outcome instrument for the evaluation of TBI victims. Diffusion tensor imaging (DTI) assesses white matter (WM) microstructure based on the displacement distribution of water molecules., Objective: To investigate WM microstructure within the first year after TBI using DTI, the patient's clinical outcomes, and associations., Methods: We scanned 20 moderate and severe TBI victims at 2 months and 1 year after the event. Imaging processing was done with the FMRIB software library; we used the tract-based spatial statistics software yielding fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) for statistical analyses. We computed the average difference between the two measures across subjects and performed a one-sample t-test and threshold-free cluster enhancement, using a corrected p-value < 0.05. Clinical outcomes were evaluated with the GOS-E. We tested for associations between outcome measures and significant mean FA clusters., Results: Significant clusters of altered FA were identified anatomically using the JHU WM atlas. We found increasing spotted areas of FA with time in the right brain hemisphere and left cerebellum. Extensive regions of increased MD, RD, and AD were observed. Patients presented an excellent overall recovery., Conclusions: There were no associations between FA and outcome scores, but we cannot exclude the existence of a small to moderate association.

Background: Diffuse axonal injury (DAI) is a frequent mechanism of traumatic brain injury (TBI) that triggers a sequence of parenchymal changes that progresses from focal axonal shear injuries up to inflammatory response and delayed axonal disconnection., Objective: The main purpose of this study is to evaluate changes in the axonal/myelinic content and the brain volume up to 12 months after TBI and to correlate these changes with neuropsychological results., Methods: Patients with DAI (n = 25) were scanned at three time points after trauma (2, 6, and 12 months), and the total brain volume (TBV), gray matter volume, and white matter volume (WMV) were calculated in each time point. The magnetization transfer ratio (MTR) for the total brain (TB MTR), gray matter (GM MTR), and white matter (WM MTR) was also quantified. In addition, Hopkins verbal learning test (HVLT), Trail Making Test (TMT), and Rey-Osterrieth Complex Figure test were performed at 6 and 12 months after the trauma., Results: There was a significant reduction in the mean TBV, WMV, TB MTR, GM MTR, and WM MTR between time points 1 and 3 (p < .05). There was also a significant difference in HVLT-immediate, TMT-A, and TMT-B scores between time points 2 and 3. The MTR decline correlated more with the cognitive dysfunction than the volume reduction., Conclusion: A progressive axonal/myelinic rarefaction and volume loss were characterized, especially in the white matter (WM) up to 1 year after the trauma. Despite that, specific neuropsychological tests revealed that patients' episodic verbal memory, attention, and executive function improved during the study. The current findings may be valuable in developing long-term TBI rehabilitation management programs., (© 2022 The Authors. Brain and Behavior published by Wiley Periodicals LLC.)

Background and Aim: Diffusion tensor imaging (DTI) parameters in the corpus callosum have been suggested to be a biomarker for prognostic outcomes in individuals with diffuse axonal injury (DAI). However, differences between the DTI parameters on moderate and severe trauma in DAI over time are still unclear. A secondary goal was to study the association between the changes in the DTI parameters, anxiety, and depressive scores in DAI over time., Methods: Twenty subjects were recruited from a neurological outpatient clinic and evaluated at 2, 6, and 12 months after the brain injury and compared to matched age and sex healthy controls regarding the DTI parameters in the corpus callosum. State-Trace Anxiety Inventory and Beck Depression Inventory were used to assess psychiatric outcomes in the TBI group over time., Results: Differences were observed in the fractional anisotropy and mean diffusivity of the genu, body, and splenium of the corpus callosum between DAI and controls (p < 0.02). Differences in both parameters in the genu of the corpus callosum were also detected between patients with moderate and severe DAI (p < 0.05). There was an increase in the mean diffusivity values and the fractional anisotropy decrease in the DAI group over time (p < 0.02). There was no significant correlation between changes in the fractional anisotropy and mean diffusivity across the study and psychiatric outcomes in DAI., Conclusion: DTI parameters, specifically the mean diffusivity in the corpus callosum, may provide reliable characterization and quantification of differences determined by the brain injury severity. No correlation was observed with DAI parameters and the psychiatric outcome scores., (© 2021. Fondazione Società Italiana di Neurologia.)

Introduction: Deficits in episodic memory following traumatic brain injury (TBI) are common and affect independence in activities of daily living. Transcranial direct current stimulation (tDCS) and concurrent cognitive training may contribute to improve episodic memory in patients with TBI. Although previous studies have shown the potential of tDCS to improve cognition, the benefits of the tDCS applied simultaneously to cognitive training in participants with neurological disorders are inconsistent. This study aims to (1) investigate whether active tDCS combined with computer-assisted cognitive training enhances episodic memory compared with sham tDCS; (2) compare the differences between active tDCS applied over the left dorsolateral prefrontal cortex (lDLPFC) and bilateral temporal cortex (BTC) on episodic memory and; (3) investigate inter and intragroup changes on cortical activity measured by quantitative electroencephalogram (qEEG)., Methods and Analysis: A randomised, parallel-group, double-blind placebo-controlled study is conducted. Thirty-six participants with chronic, moderate and severe closed TBI are being recruited and randomised into three groups (1:1:1) based on the placement of tDCS sponges and electrode activation (active or sham). TDCS is applied for 10 consecutive days for 20 min, combined with a computer-based cognitive training. Cognitive scores and qEEG are collected at baseline, on the last day of the stimulation session, and 3 months after the last tDCS session. We hypothesise that (1) the active tDCS group will improve episodic memory scores compared with the sham group; (2) differences on episodic memory scores will be shown between active BTC and lDLPFC and; (3) there will be significant delta reduction and an increase in alpha waves close to the location of the active electrodes compared with the sham group., Ethics and Dissemination: This study was approved by Hospital das Clínicas, University of São Paulo Ethical Institutional Review Border (CAAE: 87954518.0.0000.0068)., Trial Registration Number: NCT04540783., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY. Published by BMJ.)

Objective : The goal is to evaluate longitudinally with diffusion tensor imaging (DTI) the integrity of cerebral white matter in patients with moderate and severe DAI and to correlate the DTI findings with cognitive deficits. Methods : Patients with DAI (n = 20) were scanned at three timepoints (2, 6 and 12 months) after trauma. A healthy control group (n = 20) was evaluated once with the same high-field MRI scanner. The corpus callosum (CC) and the bilateral superior longitudinal fascicles (SLFs) were assessed by deterministic tractography with ExploreDTI. A neuropschychological evaluation was also performed. Results : The CC and both SLFs demonstrated various microstructural abnormalities in between-groups comparisons. All DTI parameters demonstrated changes across time in the body of the CC, while FA (fractional anisotropy) increases were seen on both SLFs. In the splenium of the CC, progressive changes in the mean diffusivity (MD) and axial diffusivity (AD) were also observed. There was an improvement in attention and memory along time. Remarkably, DTI parameters demonstrated several correlations with the cognitive domains. Conclusions : Our findings suggest that microstructural changes in the white matter are dynamic and may be detectable by DTI throughout the first year after trauma. Likewise, patients also demonstrated improvement in some cognitive skills.

Formative intervention methodologies, such as the Change Laboratory (CL), are increasingly being used in work environments. However, the learning process entailed in the application of these methodologies has received insufficient attention and may be facilitated through the use of learning platforms. We examined the development of learning and training strategies for implementing formative interventions, drawing on the experiences of a research group focusing on workers' health. Information obtained from individuals involved in CL formative activities was analyzed and interpreted using Cultural-Historical Activity Theory and the theory of expansive learning. The process of learning to implement formative interventions unfolded gradually, beginning with the interventionists' initial exposure to abstract concepts that they subsequently internalized via various mediations and applied in concrete situations. Four key interventionist training strategies used to foster collective learning were identified: (1) promoting dialogues and exchange of experiences, (2) creating environments for continuous learning and permanent discussion (seminars and post-graduate courses and the use of communication technologies), (3) creating spaces for experimentation and the practical application of concepts (case studies and participation in interventions), and (4) the use of the double stimulation method during training programs., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Lopes, Vilela, Silva-Macaia, Guirado and Querol.)

Competing Interests: Conflict of interest: None

Background: Decompressive craniectomy is a procedure required in some cases of traumatic brain injury (TBI). This manuscript evaluates the direct costs and outcomes of decompressive craniectomy for TBI in a developing country and describes the epidemiological profile., Methods: A retrospective study was performed using a five-year neurosurgical database, taking a sample of patients with TBI who underwent decompressive craniectomy. Several variables were considered and a formula was developed for calculating the total cost., Results: Most patients had multiple brain lesions and the majority (69.0%) developed an infectious complication. The general mortality index was 68.8%. The total cost was R$ 2,116,960.22 (US$ 661,550.06) and the mean patient cost was R$ 66,155.00 (US$ 20,673.44)., Conclusions: Decompressive craniectomy for TBI is an expensive procedure that is also associated with high morbidity and mortality. This was the first study performed in a developing country that aimed to evaluate the direct costs. Prevention measures should be a priority.

Background: Overactivation of NMDA-mediated excitatory processes and excess of GABA-mediated inhibition are attributed to the acute and subacute phases, respectively, after a traumatic brain injury (TBI). However, there are few studies regarding the circuitry during the chronic phase of brain injury., Objective: To evaluate the cortical excitability (CE) during the chronic phase of TBI in victims diagnosed with diffuse axonal injury (DAI)., Methods: The 22 adult subjects were evaluated after a minimum of 1 year from the onset of moderate or severe TBI. Each of the subjects first had a comprehensive neuropsychological assessment to evaluate executive functions-attention, memory, verbal fluency, and information processing speed. Then, CE assessment was performed with a circular coil applying single-pulse and paired-pulse transcranial magnetic stimulation over the cortical representation of the abductor pollicis brevis muscle on M1 of both hemispheres. The CE parameters measured were resting motor threshold (RMT), motor-evoked potentials (MEPs), short-interval intracortical inhibition (SIICI), and intracortical facilitation (ICF). All data were compared with that of a control group that consisted of the healthy age-matched individuals., Results: No significant differences between the left and right hemispheres were detected in the DAI subjects. Therefore, parameters were analyzed as pooled data. Values of RMT, MEPs, and ICF from DAI patients were within normal limits. However, SIICI values were higher in the DAI group-DAI SIICI = 1.28 (1.01; 1.87) versus the control value = 0.56 (0.33; 0.69)-suggesting that they had a disarranged inhibitory system ( p  < 0.001). By contrast, the neuropsychological findings had weak correlation with the CE data., Conclusion: As inhibition processes involve GABA-mediated circuitry, it is likely that the DAI pathophysiology itself (disruption of axons) may deplete GABA and contribute to ongoing disinhibition of these neural circuits of the cerebrum during the chronic phase of DAI.

Background and Objective: Diffuse axonal injury (DAI) induces a long-term process of brain atrophy and cognitive deficits. The goal of this study was to determine whether there are correlations between brain volume loss, microhaemorrhage load (MHL) and neuropsychological performance during the first year after DAI., Methods: Twenty-four patients with moderate or severe DAI were evaluated at 2, 6 and 12 months post-injury. MHL was evaluated at 3 months, and brain volumetry was evaluated at 3, 6 and 12 months. The trail making test (TMT) was used to evaluate executive function (EF), and the Hopkins verbal learning test (HVLT) was used to evaluate episodic verbal memory (EVM) at 6 and 12 months., Results: There were significant white matter volume (WMV), subcortical grey matter volume and total brain volume (TBV) reductions during the study period (p < 0.05). MHL was correlated only with WMV reduction. EF and EVM were not correlated with MHL but were, in part, correlated with WMV and TBV reductions., Conclusions: Our findings suggest that MHL may be a predictor of WMV reduction but cannot predict EF or EVM in DAI. Brain atrophy progresses over time, but patients showed better EF and EVM in some of the tests, which could be due to neuroplasticity.

Background: Mild traumatic brain injury (MTBI) represents 70-80% of all treated brain injuries. A considerable proportion of MTBI patients experience post-concussion symptoms for a prolonged period after MTBI, and these symptoms are diagnosed as persistent post-concussion syndrome (PPCS). PPCS is defined as a range of physical, cognitive, and emotional symptoms. However, memory and executive dysfunction seems to be one of the most debilitating symptoms. Recently, non-invasive brain stimulation has been studied as a potential treatment method for traumatic brain injury (TBI) patients. Therefore, our primary goal is to verify the effects of transcranial direct current stimulation (tDCS) in patients with PPCS who demonstrate cognitive deficits in long-term episodic memory, working memory, and executive function following MTBI., Methods/design: This is a randomized crossover trial of patients with a history of MTBI with cognitive deficits in memory and executive function. Thirty adult patients will be randomized in a crossover manner to receive three weekly sessions of anodal tDCS (2 mA) at left dorsolateral prefrontal cortex, left temporal cortex, and sham stimulation that will be performed at 7-day intervals (washout period). The clinical diagnosis of PPCS will be determined using the Rivermead Post-Concussion Symptoms Questionnaire. Patients who meet the inclusion criteria will be assessed with a neuropsychological evaluation. A new battery of computerized neuropsychological tests will be performed before and immediately after each stimulation. Statistical analysis will be performed to determine trends of cognitive improvement., Discussion: There is paucity of studies regarding the use of tDCS in TBI patients, and although recent results showed controversial data regarding the effects of tDCS in such patients, we will address specifically patients with PPCS and MTBI and no brain abnormalities on CT scan other than subarachnoid hemorrhage. Moreover, due to the missing information on literature regarding the best brain region to be studied, we will evaluate two different regions to find immediate effects of tDCS on memory and executive dysfunction., Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT02292589 (https://register.clinicaltrials.gov).