Severe Traumatic Brain Injury Patients without Focal Lesion but with Behavioral Disorders: Shrinkage of Gray Matter Nuclei and Thalamus Revealed in a Pilot Voxel-Based MRI Study

Abnormal regional homogeneity as a potential imaging indicator for identifying adolescent-onset schizophrenia: Insights from resting-state functional magnetic resonance imaging

BACKGROUND

In patients with schizophrenia, there is abnormal regional functional synchrony. However, whether it also in patients with adolescent-onset schizophrenia (AOS) remains unclear. The goal of this study was to analyze the regional homogeneity (ReHo) of resting functional magnetic resonance imaging to explore the functional abnormalities of the brain in patients with AOS.

METHODS

The study included 107 drug-naive first-episode AOS patients and 67 healthy, age, sex, and education-matched controls using resting-state functional magnetic resonance imaging scans. The ReHo method was used to analyze the imaging dataset.

RESULTS

Compared with the control group, the ReHo values of the right inferior frontal gyrus orbital part, right middle frontal gyrus (MFG.R), left inferior parietal, but supramarginal and angular gyri, and left precentral gyrus (PreCG.L) were significantly increased and the ReHo value of the left posterior cingulate cortex/anterior cuneiform lobe was significantly decreased in schizophrenia patients. ROC analysis showed that the ReHo values of the MFG.R and PreCG.L might be regarded as potential markers in helping to identify patients. Furthermore, the PANSS scores in the patient group and the ReHo values showed a positive correlation between MFG.R ReHo values and general scores.

CONCLUSIONS

Our results suggested that AOS patients had ReHo abnormalities. The ReHo values of these abnormal regions may serve as potential imaging biomarkers for the identification of AOS patients.

Deep Grey Matter Volume is Reduced in Amateur Boxers as Compared to Healthy Age-matched Controls

Purpose

Mild traumatic brain injuries (mTBI) sustained during contact sports like amateur boxing are found to have long-term sequelae, being linked to an increased risk of developing neurological conditions like Parkinson’s disease. The aim of this study was to assess differences in volume of anatomical brain structures between amateur boxers and control subjects with a special interest in the affection of deep grey matter structures.

Methods

A total of 19 amateur boxers and 19 healthy controls (HC), matched for age and intelligence quotient (IQ), underwent 3T magnetic resonance imaging (MRI) as well as neuropsychological testing. Body mass index (BMI) was evaluated for every subject and data about years of boxing training and number of fights were collected for each boxer. The acquired 3D high resolution T1 weighted MR images were analyzed to measure the volumes of cortical grey matter (GM), white matter (WM), cerebrospinal fluid (CSF) and deep grey matter structures. Multivariate analysis was applied to reveal differences between groups referencing deep grey matter structures to normalized brain volume (NBV) to adjust for differences in head size and brain volume as well as adding BMI as cofactor.

Results

Total intracranial volume (TIV), comprising GM, WM and CSF, was lower in boxers compared to controls (by 7.1%, P = 0.009). Accordingly, GM (by 5.5%, P = 0.038) and WM (by 8.4%, P = 0.009) were reduced in boxers. Deep grey matter showed statistically lower volumes of the thalamus (by 8.1%, P = 0.006), caudate nucleus (by 11.1%, P = 0.004), putamen (by 8.1%, P = 0.011), globus pallidus (by 9.6%, P = 0.017) and nucleus accumbens (by 13.9%, P = 0.007) but not the amygdala (by 5.5%, P = 0.221), in boxers compared to HC.

Conclusion

Several deep grey matter structures were reduced in volume in the amateur boxer group. Furthermore, longitudinal studies are needed to determine the damage pattern affecting deep grey matter structures and its neuropsychological relevance.

Global hippocampal and selective thalamic nuclei atrophy differentiate chronic TBI from Non-TBI

Traumatic brain injury (TBI) may increase susceptibility to neurodegenerative diseases later in life. One neurobiological parallel between chronic TBI and neurodegeneration may be accelerated aging and the nature of atrophy across subcortical gray matter structures. The main aim of the present investigation is to evaluate and rank the degree that subcortical gray matter atrophy differentiates chronic moderate-severe TBI from non-TBI participants by evaluating morphometric differences between groups. Forty individuals with moderate-severe chronic TBI (9.23 yrs from injury) and 33 healthy controls (HC) underwent high resolution 3D T1-weighted structural magnetic resonance imaging. Whole brain volume was classified into white matter, cortical and subcortical gray matter structures with hippocampi and thalami further segmented into subfields and nuclei, respectively. Extensive atrophy was observed across nearly all brain regions for chronic TBI participants. A series of multivariate logistic regression models identified subcortical gray matter structures of the hippocampus and thalamus as the most sensitive to differentiating chronic TBI from non-TBI participants (McFadden R² = .36, p < .001). Further analyses revealed the pattern of hippocampal atrophy to be global, occurring across nearly all subfields. The pattern of thalamic atrophy appeared to be much more selective and non-uniform, with largest between-group differences evident for nuclei bordering the ventricles. Subcortical gray matter was negatively correlated with time since injury (r = -.31, p = .054), while white matter and cortical gray matter were not. Cognitive ability was lower in the chronic TBI group (Cohen's d = .97, p = .003) and correlated with subcortical structures including the pallidum (r² = .23, p = .038), thalamus (r² = .36, p = .007) and ventral diencephalon (r² = .23, p = .036). These data may support an accelerated aging hypothesis in chronic moderate-severe TBI that coincides with a similar neuropathological profile found in neurodegenerative diseases.

Impact of Curcumin on Traumatic Brain Injury and Involved Molecular Signaling Pathways

Traumatic Brain Injury (TBI) is one of the main causes of mortality and morbidity worldwide with no suitable treatment. The present study was designed to review the present literature about the protective effects of curcumin and the underlying mechanism against TBI. All published English language papers from beginning to 2019 were selected in this study. The findings indicate that curcumin may be effective against TBI outcomes by modulating the molecular signaling pathways involved in oxidative stress, inflammation, apoptosis, and autophagy. However, more experimental studies should be done to identify all mechanisms involved in the pathogenesis of TBI. Patents for Curcumin and chronic inflammation and traumatic brain injury management (WO2017097805A1 and US9101580B2) were published. In conclusion, the present study confirmed the potential therapeutic impact of curcumin for treating TBI.

Emerging Utility of Applied Magnetic Resonance Imaging in the Management of Traumatic Brain Injury

Traumatic brain injury (TBI) is a widespread and expensive problem globally. The standard diagnostic workup for new TBI includes obtaining a noncontrast computed tomography image of the head, which provides quick information on operative pathologies. However, given the limited sensitivity of computed tomography for identifying subtle but meaningful changes in the brain, magnetic resonance imaging (MRI) has shown better utility for ongoing management and prognostication after TBI. In recent years, advanced applications of MRI have been further studied and are being implemented as clinical tools to help guide care. These include functional MRI, diffusion tensor imaging, MR perfusion, and MR spectroscopy. In this review, we discuss the scientific basis of each of the above techniques, the literature supporting their use in TBI, and how they may be clinically implemented to improve the care of TBI patients.

The Shrinking Brain: Cerebral Atrophy Following Traumatic Brain Injury

Cerebral atrophy in response to traumatic brain injury is a well-documented phenomenon in both primary investigations and review articles. Recent atrophy studies focus on exploring the region-specific patterns of cerebral atrophy; yet, there is no study that analyzes and synthesizes the emerging atrophy patterns in a single comprehensive review. Here we attempt to fill this gap in our current knowledge by integrating the current literature into a cohesive theory of preferential brain tissue loss and by identifying common risk factors for accelerated atrophy progression. Our review reveals that observations for mild traumatic brain injury remain inconclusive, whereas observations for moderate-to-severe traumatic brain injury converge towards robust patterns: brain tissue loss is on the order of 5% per year, and occurs in the form of generalized atrophy, across the entire brain, or focal atrophy, in specific brain regions. The most common regions of focal atrophy are the thalamus, hippocampus, and cerebellum in gray matter and the corpus callosum, corona radiata, and brainstem in white matter. We illustrate the differences of generalized and focal gray and white matter atrophy on emerging deformation and stress profiles across the whole brain using computational simulation. The characteristic features of our atrophy simulations-a widening of the cortical sulci, a gradual enlargement of the ventricles, and a pronounced cortical thinning-agree well with clinical observations. Understanding region-specific atrophy patterns in response to traumatic brain injury has significant implications in modeling, simulating, and predicting injury outcomes. Computational modeling of brain atrophy could open new strategies for physicians to make informed decisions for whom, how, and when to administer pharmaceutical treatment to manage the chronic loss of brain structure and function.

Complement cascade on severe traumatic brain injury patients at the chronic unconscious stage: implication for pathogenesis

BACKGROUND

Patients who awake from severely traumatic brain injury (TBI) may remain unconscious for many years. Although behavioral assessment and functional imaging are currently used as diagnostic tools, the molecular basis underlying chronic condition has yet to be explored.

METHOD

Plasma samples were obtained at 3 time points (1, 3 and 6 months) from 18 patients with chronic disorders of consciousness who survived severe TBI, and 6 healthy volunteers. A coupled isobaric tag for relative and absolute quantitation (iTRAQ)-based proteomics approach was used to screen differentially expressed proteins (DEPs) between patients and controls. Potential molecular mechanisms were further discussed through bioinformatics analyses.

RESULT

In total, 300 plasma proteins <1% false discovery rates were identified and 32 proteins were consistently altered between patients and controls. Biological pathway analysis revealed that the DEPs were predominantly involved in complement cascade.

CONCLUSIONS

This study discussed potential mechanisms of complement cascade underlying chronic stage in severe TBI.