scholarly journals Compensation through Functional Hyperconnectivity: A Longitudinal Connectome Assessment of Mild Traumatic Brain Injury

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Armin Iraji ◽  
Hanbo Chen ◽  
Natalie Wiseman ◽  
Robert D. Welch ◽  
Brian J. O’Neil ◽  
...  

Mild traumatic brain injury (mTBI) is a major public health concern. Functional MRI has reported alterations in several brain networks following mTBI. However, the connectome-scale brain network changes are still unknown. In this study, sixteen mTBI patients were prospectively recruited from an emergency department and followed up at 4–6 weeks after injury. Twenty-four healthy controls were also scanned twice with the same time interval. Three hundred fifty-eight brain landmarks that preserve structural and functional correspondence of brain networks across individuals were used to investigate longitudinal brain connectivity. Network-based statistic (NBS) analysis did not find significant difference in the group-by-time interaction and time effects. However, 258 functional pairs show group differences in which mTBI patients have higher functional connectivity. Meta-analysis showed that “Action” and “Cognition” are the most affected functional domains. Categorization of connectomic signatures using multiview group-wise cluster analysis identified two patterns of functional hyperconnectivity among mTBI patients: (I) between the posterior cingulate cortex and the association areas of the brain and (II) between the occipital and the frontal lobes of the brain. Our results demonstrate that brain concussion renders connectome-scale brain network connectivity changes, and the brain tends to be hyperactivated to compensate the pathophysiological disturbances.

2021 ◽  
Vol 33 (1) ◽  
pp. 67-95 ◽  
Author(s):  
David Gabrieli ◽  
Samantha N. Schumm ◽  
Nicholas F. Vigilante ◽  
David F. Meaney

Mild traumatic brain injury (mTBI) presents a significant health concern with potential persisting deficits that can last decades. Although a growing body of literature improves our understanding of the brain network response and corresponding underlying cellular alterations after injury, the effects of cellular disruptions on local circuitry after mTBI are poorly understood. Our group recently reported how mTBI in neuronal networks affects the functional wiring of neural circuits and how neuronal inactivation influences the synchrony of coupled microcircuits. Here, we utilized a computational neural network model to investigate the circuit-level effects of N-methyl D-aspartate receptor dysfunction. The initial increase in activity in injured neurons spreads to downstream neurons, but this increase was partially reduced by restructuring the network with spike-timing-dependent plasticity. As a model of network-based learning, we also investigated how injury alters pattern acquisition, recall, and maintenance of a conditioned response to stimulus. Although pattern acquisition and maintenance were impaired in injured networks, the greatest deficits arose in recall of previously trained patterns. These results demonstrate how one specific mechanism of cellular-level damage in mTBI affects the overall function of a neural network and point to the importance of reversing cellular-level changes to recover important properties of learning and memory in a microcircuit.


2018 ◽  
pp. 110-119

Primary Objectives: By extending the scope of knowledge of the primary care optometrist, the brain injury population will have expanded access to entry level neurooptometric care by optometric providers who have a basic understanding of their neurovisual problems, be able to provide some treatment and know when to refer to their colleagues who have advanced training in neuro-optometric rehabilitation.


2021 ◽  
Vol 6 (1) ◽  
pp. e000717
Author(s):  
Panu Teeratakulpisarn ◽  
Phati Angkasith ◽  
Thanakorn Wannakul ◽  
Parichat Tanmit ◽  
Supatcha Prasertcharoensuk ◽  
...  

BackgroundAlthough there are eight factors known to indicate a high risk of intracranial hemorrhage (ICH) in mild traumatic brain injury (TBI), identification of the strongest of these factors may optimize the utility of brain CT in clinical practice. This study aimed to evaluate the predictors of ICH based on baseline characteristics/mode of injury, indications for brain CT, and a combination of both to determine the strongest indicator.MethodsThis was a descriptive, retrospective, analytical study. The inclusion criteria were diagnosis of mild TBI, high risk of ICH, and having undergone a CT scan of the brain. The outcome of the study was any type of ICH. Stepwise logistic regression analysis was used to find the strongest predictors according to three models: (1) injury pattern and baseline characteristics, (2) indications for CT scan of the brain, and (3) a combination of models 1 and 2.ResultsThere were 100 patients determined to be at risk of ICH based on indications for CT of the brain in patients with acute head injury. Of these, 24 (24.00%) had ICH. Model 1 found that injury due to motor vehicle crash was a significant predictor of ICH, with an adjusted OR (95% CI) of 11.53 (3.05 to 43.58). Models 2 and 3 showed Glasgow Coma Scale (GCS) score of 13 to 14 after 2 hours of observation and open skull or base of skull fracture to be independent predictors, with adjusted OR (95% CI) of 11.77 (1.32 to 104.96) and 5.88 (1.08 to 31.99) according to model 2.DiscussionOpen skull or base of skull fracture and GCS score of 13 to 14 after 2 hours of observation were the two strongest predictors of ICH in mild TBI.Level of evidenceIII.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Huazhen Chen ◽  
Karl Kevala ◽  
Elma Aflaki ◽  
Juan Marugan ◽  
Hee-Yong Kim

Abstract Background Repetitive mild traumatic brain injury (mTBI) can result in chronic visual dysfunction. G-protein receptor 110 (GPR110, ADGRF1) is the target receptor of N-docosahexaenoylethanolamine (synaptamide) mediating the anti-neuroinflammatory function of synaptamide. In this study, we evaluated the effect of an endogenous and a synthetic ligand of GPR110, synaptamide and (4Z,7Z,10Z,13Z,16Z,19Z)-N-(2-hydroxy-2-methylpropyl) docosa-4,7,10,13,16,19-hexaenamide (dimethylsynaptamide, A8), on the mTBI-induced long-term optic tract histopathology and visual dysfunction using Closed-Head Impact Model of Engineered Rotational Acceleration (CHIMERA), a clinically relevant model of mTBI. Methods The brain injury in wild-type (WT) and GPR110 knockout (KO) mice was induced by CHIMERA applied daily for 3 days, and GPR110 ligands were intraperitoneally injected immediately following each impact. The expression of GPR110 and proinflammatory mediator tumor necrosis factor (TNF) in the brain was measured by using real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) in an acute phase. Chronic inflammatory responses in the optic tract and visual dysfunction were assessed by immunostaining for Iba-1 and GFAP and visual evoked potential (VEP), respectively. The effect of GPR110 ligands in vitro was evaluated by the cyclic adenosine monophosphate (cAMP) production in primary microglia isolated from adult WT or KO mouse brains. Results CHIMERA injury acutely upregulated the GPR110 and TNF gene level in mouse brain. Repetitive CHIMERA (rCHIMERA) increased the GFAP and Iba-1 immunostaining of glia cells and silver staining of degenerating axons in the optic tract with significant reduction of N1 amplitude of visual evoked potential at up to 3.5 months after injury. Both GPR110 ligands dose- and GPR110-dependently increased cAMP in cultured primary microglia with A8, a ligand with improved stability, being more effective than synaptamide. Intraperitoneal injection of A8 at 1 mg/kg or synaptamide at 5 mg/kg significantly reduced the acute expression of TNF mRNA in the brain and ameliorated chronic optic tract microgliosis, astrogliosis, and axonal degeneration as well as visual deficit caused by injury in WT but not in GPR110 KO mice. Conclusion Our data demonstrate that ligand-induced activation of the GPR110/cAMP system upregulated after injury ameliorates the long-term optic tract histopathology and visual impairment caused by rCHIMERA. Based on the anti-inflammatory nature of GPR110 activation, we suggest that GPR110 ligands may have therapeutic potential for chronic visual dysfunction associated with mTBI.


2012 ◽  
Vol 58 (7) ◽  
pp. 1116-1122 ◽  
Author(s):  
Damien Bouvier ◽  
Mathilde Fournier ◽  
Jean-Benoît Dauphin ◽  
Flore Amat ◽  
Sylvie Ughetto ◽  
...  

Abstract BACKGROUND The place of serum S100B measurement in mild traumatic brain injury (mTBI) management is still controversial. Our prospective study aimed to evaluate its utility in the largest child cohort described to date. METHODS Children younger than 16 years presenting at a pediatric emergency department within 3 h after TBI were enrolled prospectively for blood sampling to determine serum S100B concentrations. The following information was collected: TBI severity determined by using the Masters classification [1: minimal or Glasgow Coma Scale (GCS) 15, 2: mild or GCS 13–15, and 3: severe or GCS <13]; whether hospitalized or not; good or bad clinical evolution (CE); whether cranial computed tomography (CCT) was prescribed; and related presence (CCT+) or absence (CCT−) of lesions. RESULTS For the 446 children enrolled, the median concentrations of S100B were 0.21, 0.31, and 0.44 μg/L in Masters groups 1, 2, and 3, respectively, with a statistically significant difference between these groups (P < 0.05). In Masters group 2, 65 CCT scans were carried out. Measurement of S100B identified patients as CCT+ with 100% (95% CI 85–100) sensitivity and 33% (95% CI 20–50) specificity. Of the 424 children scored Masters 1 or 2, 21 presented “bad CE.” S100B identified bad CE patients with 100% (95% CI 84–100) sensitivity and 36% (95% CI 31–41) specificity. Of the 242 children hospitalized, 81 presented an S100B concentration within the reference interval. CONCLUSIONS Serum S100B determination during the first 3 h of management of children with mTBI has the potential to reduce the number of CCT scans, thereby avoiding unnecessary irradiation, and to save hospitalization costs.


2020 ◽  
Vol 14 ◽  
Author(s):  
Francesca Buhagiar ◽  
Melinda Fitzgerald ◽  
Jason Bell ◽  
Fiona Allanson ◽  
Carmela Pestell

Background: Mild traumatic brain injury (mTBI) results from an external force to the head or body causing neurophysiological changes within the brain. The number and severity of symptoms can vary, with some individuals experiencing rapid recovery, and others having persistent symptoms for months to years, impacting their quality of life. Current rehabilitation is limited in its ability to treat persistent symptoms and novel approaches are being sought to improve outcomes following mTBI. Neuromodulation is one technique used to encourage adaptive neuroplasticity within the brain.Objective: To systematically review the literature on the efficacy of neuromodulation in the mTBI population.Method: A systematic review was conducted using Medline, Embase, PsycINFO, PsycARTICLES and EBM Review. Preferred Reporting Items for Systematic Reviews and the Synthesis Without Meta-analysis reporting guidelines were used and a narrative review of the selected studies was completed. Fourteen articles fulfilled the inclusion criteria which were published in English, investigating an adult sample and using a pre- and post-intervention design. Studies were excluded if they included non-mild TBI severities, pediatric or older adult populations.Results: Thirteen of fourteen studies reported positive reductions in mTBI symptomatology following neuromodulation. Specifically, improvements were reported in post-concussion symptom ratings, headaches, dizziness, depression, anxiety, sleep disturbance, general disability, cognition, return to work and quality of life. Normalization of working memory activation patterns, vestibular field potentials, hemodynamics of the dorsolateral prefrontal cortex and excessive delta wave activity were also seen. The studies reviewed had several methodological limitations including small, heterogenous samples and varied intervention protocols, limiting generalisability. Further research is required to understand the context in which neuromodulation may be beneficial.Conclusions: While these positive effects are observed, limitations included unequal representation of neuromodulation modalities in the literature, and lack of literature describing the efficacy of neuromodulation on the development or duration of persistent mTBI symptoms. Better clarity regarding neuromodulation efficacy could have a significant impact on mTBI patients, researchers, clinicians, and policy makers, facilitating a more productive post-mTBI population. Despite the limitations, the literature indicates that neuromodulation warrants further investigation. PROSPERO registration number: CRD42020161279.


2011 ◽  
Vol 79 (2) ◽  
pp. 89-96 ◽  
Author(s):  
Vasso Tsirka ◽  
Panagiotis G. Simos ◽  
Antonios Vakis ◽  
Kassiani Kanatsouli ◽  
Michael Vourkas ◽  
...  

2008 ◽  
Vol 108 (3) ◽  
pp. 575-587 ◽  
Author(s):  
Guy Rosenthal ◽  
Diane Morabito ◽  
Mitchell Cohen ◽  
Annina Roeytenberg ◽  
Nikita Derugin ◽  
...  

Object Traumatic brain injury (TBI) often occurs as part of a multisystem trauma that may lead to hemorrhagic shock. Effective resuscitation and restoration of oxygen delivery to the brain is important in patients with TBI because hypotension and hypoxia are associated with poor outcome in head injury. We studied the effects of hemoglobin-based oxygen-carrying (HBOC)–201 solution compared with lactated Ringer (LR) solution in a large animal model of brain injury and hemorrhage, in a blinded prospective randomized study. Methods Swine underwent brain impact injury and hemorrhage to a mean arterial pressure (MAP) of 40 mm Hg. Twenty swine were randomized to undergo resuscitation with HBOC-201 (6 ml/kg) or LR solution (12 ml/kg) and were observed for an average of 6.5 ± 0.5 hours following resuscitation. At the end of the observation period, magnetic resonance (MR) imaging was performed. Histological studies of swine brains were performed using Fluoro-Jade B, a marker of early neuronal degeneration. Results Swine resuscitated with HBOC-201 had higher MAP, higher cerebral perfusion pressure (CPP), improved base deficit, and higher brain tissue oxygen tension (PbtO2) than animals resuscitated with LR solution. No significant difference in total injury volume on T2-weighted MR imaging was observed between animals resuscitated with HBOC-201 solution (1155 ± 374 mm3) or LR solution (1246 ± 279 mm3; p = 0.55). On the side of impact injury, no significant difference in the mean number of Fluoro-Jade B–positive cells/hpf was seen between HBOC-201 solution (61.5 ± 14.7) and LR solution (48.9 ± 17.7; p = 0.13). Surprisingly, on the side opposite impact injury, a significant increase in Fluoro-Jade B–positive cells/hpf was seen in animals resuscitated with LR solution (42.8 ± 28.3) compared with those resuscitated with HBOC-201 solution (5.6 ± 8.1; p < 0.05), implying greater neuronal injury in LR-treated swine. Conclusions The improved MAP, CPP, and PbtO2 observed with HBOC-201 solution in comparison with LR solution indicates that HBOC-201 solution may be a preferable agent for small-volume resuscitation in brain-injured patients with hemorrhage. The use of HBOC-201 solution appears to decrease cellular degeneration in the brain area not directly impacted by the primary injury. Hemoglobin-based oxygen-carrying–201 solution may act by improving cerebral blood flow or increasing the oxygen-carrying capacity of blood, mitigating a second insult to the injured brain.


2014 ◽  
Vol 8 (1) ◽  
pp. 14-19 ◽  
Author(s):  
Jéssica Natuline Ianof ◽  
Fabio Rios Freire ◽  
Vanessa Tomé Gonçalves Calado ◽  
Juliana Rhein Lacerda ◽  
Fernanda Coelho ◽  
...  

ABSTRACT Traumatic brain injury (TBI) is a major cause of lifelong disability and death worldwide. Sport-related traumatic brain injury is an important public health concern. The purpose of this review was to highlight the importance of sport-related concussions. Concussion refers to a transient alteration in consciousness induced by external biomechanical forces transmitted directly or indirectly to the brain. It is a common, although most likely underreported, condition. Contact sports such as American football, rugby, soccer, boxing, basketball and hockey are associated with a relatively high prevalence of concussion. Various factors may be associated with a greater risk of sport-related concussion, such as age, sex, sport played, level of sport played and equipment used. Physical complaints (headache, fatigue, dizziness), behavioral changes (depression, anxiety, irritability) and cognitive impairment are very common after a concussion. The risk of premature return to activities includes the prolongation of post-concussive symptoms and increased risk of concussion recurrence.


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