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Tweedale M, Morys F, Pastor-Bernier A, Azizi H, Tremblay C, Dagher A. Obesity and diffusion-weighted imaging of subcortical grey matter in young and older adults. Appetite 2024; 200:107527. [PMID: 38797235 DOI: 10.1016/j.appet.2024.107527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 05/21/2024] [Accepted: 05/24/2024] [Indexed: 05/29/2024]
Abstract
Obesity and hypothalamic inflammation are causally related. It is unclear whether this neuroinflammation precedes or results from obesity. Animal studies show that an increase in food intake can lead to hypothalamic inflammation, but hypothalamic inflammation can create a feedback loop that further increases food intake. Internal and external factors mediate patterns of food intake and how it can affect the hypothalamus. Measures of water diffusivity in magnetic resonance imaging of the brain such as fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD) are associated with grey matter inflammation. Here, we investigated how those measures are associated with obesity-related variables in groups of young and older adults. We found relationships between decreased diffusivity and obesity markers in young adults. In older adults, obesity and comorbidities were also related to significant changes in diffusivity. Here, diffusivity was strongly associated with body mass index (BMI) and blood levels of C-reactive protein (CRP) in multiple subcortical regions, rather than only the hypothalamus. Our results suggest that diffusivity measures can be used to investigate obesity-associated changes in the brain that can potentially reflect neuroinflammation. The connection seen between subcortical inflammation and obesity opens the conversation on preventative interventions needed to reduce the effects of obesity at all stages in life.
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Affiliation(s)
- Max Tweedale
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Filip Morys
- Montreal Neurological Institute, McGill University, Montreal, Canada.
| | | | - Houman Azizi
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | | | - Alain Dagher
- Montreal Neurological Institute, McGill University, Montreal, Canada
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2
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Du D, Zheng T, Wang Z, Chen Y, Wu S, Yang L, Lu J, Liu L. Evaluating the therapeutic effect of LIPUS in the early stage of traumatic brain injury using FA and T2 * in rats. Aging (Albany NY) 2024; 16:206060. [PMID: 39137314 DOI: 10.18632/aging.206060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 07/16/2024] [Indexed: 08/15/2024]
Abstract
To evaluate the protective effect of LIPUS at the early stage of brain trauma in rats, 45 rats were randomly divided into 3 groups: sham (n = 15), TBI (n = 15) and LIPUS treatment groups (n = 15). Ipsilateral and contralateral cortical and thalamic parameters obtained by diffusion tensor imaging (DTI) and fast low-angle shot magnetic resonance imaging (FLASH-MRI) were measured at different times after trauma. For fractional anisotropy (FA) and T2* values, two-way repeated measures ANOVA with Tukey's post hoc was used for intergroup comparisons. With observation time prolonged, the FA values of the ipsilateral cortex in the TBI group gradually increased and were significantly higher than those in the LIPUS treatment group on Day 7 (adjusted P = 0.0067). FA values in the contralateral cortex decreased at this time and were significantly lower than those in the LIPUS treatment group (adjusted P = 0.0192). Meanwhile, compared with LIPUS group, FA values were significantly higher in the injured thalamus (adjusted P = 0.0025). Combined with correlation analysis, FA values were positively correlated with neuronal damage (P = 0.0148, r2 = 0.895). At 7 days after trauma, T2* values in the ipsilateral cortex of the TBI group were significantly lower. After analysis of ferritin content and correlation, we found that T2* values were negatively correlated with ferritin (P = 0.0259, r2 = -0.849). By measuring post-traumatic changes in FA and T2* values, it is possible to demonstrate a neuronal protective effect of LIPUS in the early phase of TBI rats and promote brain rehabilitation.
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Affiliation(s)
- Dan Du
- Department of Magnetic Resonance Imaging, Qinhuangdao Municipal No. 1 Hospital, Qinhuangdao, China
- Department of Radiology, Peking University Third Hospital, Beijing, China
| | - Tao Zheng
- Department of Magnetic Resonance Imaging, Qinhuangdao Municipal No. 1 Hospital, Qinhuangdao, China
| | - Zhanqiu Wang
- Department of Magnetic Resonance Imaging, Qinhuangdao Municipal No. 1 Hospital, Qinhuangdao, China
| | - Yansheng Chen
- Department of Magnetic Resonance Imaging, Qinhuangdao Municipal No. 1 Hospital, Qinhuangdao, China
| | - Shuo Wu
- Department of Magnetic Resonance Imaging, Qinhuangdao Municipal No. 1 Hospital, Qinhuangdao, China
| | - Linsha Yang
- Department of Magnetic Resonance Imaging, Qinhuangdao Municipal No. 1 Hospital, Qinhuangdao, China
| | - Jiabin Lu
- Department of Radiology, Peking University Third Hospital, Beijing, China
- Institute of Medical Technology, Peking University Health Science Center, Beijing, China
| | - Lanxiang Liu
- Department of Magnetic Resonance Imaging, Qinhuangdao Municipal No. 1 Hospital, Qinhuangdao, China
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3
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Cheng C, Lu CF, Hsieh BY, Huang SH, Kao YCJ. Anisotropy component of DTI reveals long-term neuroinflammation following repetitive mild traumatic brain injury in rats. Eur Radiol Exp 2024; 8:82. [PMID: 39046630 PMCID: PMC11269550 DOI: 10.1186/s41747-024-00490-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Accepted: 06/18/2024] [Indexed: 07/25/2024] Open
Abstract
BACKGROUND This study aimed to investigate the long-term effects of repetitive mild traumatic brain injury (rmTBI) with varying inter-injury intervals by measuring diffusion tensor metrics, including mean diffusivity (MD), fractional anisotropy (FA), and diffusion magnitude (L) and pure anisotropy (q). METHODS Eighteen rats were randomly divided into three groups: short-interval rmTBI (n = 6), long-interval rmTBI (n = 6), and sham controls (n = 6). MD, FA, L, and q values were analyzed from longitudinal diffusion tensor imaging at days 50 and 90 after rmTBI. Immunohistochemical staining against neurons, astrocytes, microglia, and myelin was performed. Analysis of variance, Pearson correlation coefficient, and simple linear regression model were used. RESULTS At day 50 post-rmTBI, lower cortical FA and q values were shown in the short-interval group (p ≤ 0.038). In contrast, higher FA and q values were shown for the long-interval group (p ≤ 0.039) in the corpus callosum. In the ipsilesional external capsule and internal capsule, no significant changes were found in FA, while lower L and q values were shown in the short-interval group (p ≤ 0.028) at day 90. The q values in the external capsule and internal capsule were negatively correlated with the number of microglial cells and the total number of astroglial cells (p ≤ 0.035). CONCLUSION Tensor scalar measurements, such as L and q values, are sensitive to exacerbated chronic injury induced by rmTBI with shorter inter-injury intervals and reflect long-term astrogliosis induced by the cumulative injury. RELEVANCE STATEMENT Tensor scalar measurements, including L and q values, are potential DTI metrics for detecting long-term and subtle injury following rmTBI; in particular, q values may be used for quantifying remote white matter (WM) changes following rmTBI. KEY POINTS The alteration of L and q values was demonstrated after chronic repetitive mild traumatic brain injury. Changing q values were observed in the impact site and remote WM. The lower q values in the remote WM were associated with astrogliosis.
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Affiliation(s)
- Ching Cheng
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chia-Feng Lu
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Bao-Yu Hsieh
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Shu-Hui Huang
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yu-Chieh Jill Kao
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan.
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Corrigan F, Arulsamy A, Shultz SR, Wright DK, Collins-Praino LE. Initial Severity of Injury Has Little Effect on the Temporal Profile of Long-Term Deficits in Locomotion, Anxiety, and Cognitive Function After Diffuse Traumatic Brain Injury. Neurotrauma Rep 2023; 4:41-50. [PMID: 36726871 PMCID: PMC9886190 DOI: 10.1089/neur.2022.0057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Traumatic brain injury (TBI) is associated with persistent impairments in multiple domains, including cognitive and neuropsychiatric function. Previous literature has suggested that the risk of such impairments may differ as a function of the initial severity of injury, with moderate-severe TBI (msTBI) associated with more severe cognitive dysfunction and mild TBI (mTBI) associated with a higher risk of developing an anxiety disorder. Despite this, relatively few pre-clinical studies have investigated the time course of behavioral change after different severities of injury. The current study compared the temporal profile of functional deficits incorporating locomotion, cognition, and anxiety up to 12 months post-injury after an mTBI, repeated mild TBI (rmTBI), and single msTBI in an experimental model of diffuse TBI. Injury appeared to alter the effect of aging on locomotor activity, with both msTBI and rmTBI rats showing a decrease in locomotion at 12 months relative to their earlier performance on the task, an effect not observed in shams or after a single mTBI. Further, mTBI seemed to be associated with decreased anxiety over time, as measured by increased time spent in the open arm of the elevated plus maze from 3 to 12 months post-injury. No significant findings were observed on spatial memory or volumetric magnetic resonance imaging. Future studies will need to use a more comprehensive behavioral battery, capable of capturing subtle alterations in function, and longer time points, following rats into old age, in order to more fully assess the evolution of persistent behavioral deficits in key domains after different severities of TBI, as well as their accompanying neuroimaging changes. Given the prevalence and significance of such deficits post-TBI for a person's quality of life, as well as the elevated risk of neurodegenerative disease post-injury, such investigations may play a critical role in identifying optimal windows of therapeutic intervention post-injury.
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Affiliation(s)
- Frances Corrigan
- Head Injury Lab, Division of Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Alina Arulsamy
- Cognition, Ageing and Neurodegenerative Disease Lab, School of Biomedicine, The University of Adelaide, Adelaide, South Australia, Australia
| | - Sandy R. Shultz
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Health and Human Services, Vancouver Island University, Nanaimo, British Columbia, Canada
| | - David K. Wright
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Lyndsey E. Collins-Praino
- Cognition, Ageing and Neurodegenerative Disease Lab, School of Biomedicine, The University of Adelaide, Adelaide, South Australia, Australia.,Address correspondence to: Lyndsey E. Collins-Praino, PhD, Discipline of Anatomy and Pathology, School of Biomedicine, University of Adelaide, Adelaide, South Australia, Australia 5005;
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5
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Sun CC, Zhang YW, Xing XX, Yang Q, Cao LY, Cheng YF, Zhao JW, Zhou ST, Cheng DD, Zhang Y, Hua XY, Wang H, Xu DS. Modified constraint-induced movement therapy enhances cortical plasticity in a rat model of traumatic brain injury: a resting-state functional MRI study. Neural Regen Res 2023; 18:410-415. [PMID: 35900438 PMCID: PMC9396520 DOI: 10.4103/1673-5374.344832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Modified constraint-induced movement therapy (mCIMT) has shown beneficial effects on motor function improvement after brain injury, but the exact mechanism remains unclear. In this study, amplitude of low frequency fluctuation (ALFF) metrics measured by resting-state functional magnetic resonance imaging was obtained to investigate the efficacy and mechanism of mCIMT in a control cortical impact (CCI) rat model simulating traumatic brain injury. At 3 days after control cortical impact model establishment, we found that the mean ALFF (mALFF) signals were decreased in the left motor cortex, somatosensory cortex, insula cortex and the right motor cortex, and were increased in the right corpus callosum. After 3 weeks of an 8-hour daily mCIMT treatment, the mALFF values were significantly increased in the bilateral hemispheres compared with those at 3 days postoperatively. The mALFF signal values of left corpus callosum, left somatosensory cortex, right medial prefrontal cortex, right motor cortex, left postero dorsal hippocampus, left motor cortex, right corpus callosum, and right somatosensory cortex were increased in the mCIMT group compared with the control cortical impact group. Finally, we identified brain regions with significantly decreased mALFF values at 3 days postoperatively. Pearson correlation coefficients with the right forelimb sliding score indicated that the improvement in motor function of the affected upper limb was associated with an increase in mALFF values in these brain regions. Our findings suggest that functional cortical plasticity changes after brain injury, and that mCIMT is an effective method to improve affected upper limb motor function by promoting bilateral hemispheric cortical remodeling. mALFF values correlate with behavioral changes and can potentially be used as biomarkers to assess dynamic cortical plasticity after traumatic brain injury.
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San Martín Molina I, Fratini M, Campi G, Burghammer M, Grünewald TA, Salo RA, Narvaez O, Aggarwal M, Tohka J, Sierra A. A multiscale tissue assessment in a rat model of mild traumatic brain injury. J Neuropathol Exp Neurol 2022; 82:71-83. [PMID: 36331507 PMCID: PMC9764078 DOI: 10.1093/jnen/nlac100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Diffusion tensor imaging (DTI) has demonstrated the potential to assess the pathophysiology of mild traumatic brain injury (mTBI) but correlations of DTI findings and pathological changes in mTBI are unclear. We evaluated the potential of ex vivo DTI to detect tissue damage in a mild mTBI rat model by exploiting multiscale imaging methods, histology and scanning micro-X-ray diffraction (SμXRD) 35 days after sham-operation (n = 2) or mTBI (n = 3). There were changes in DTI parameters rostral to the injury site. When examined by histology and SμXRD, there was evidence of axonal damage, reduced myelin density, gliosis, and ultrastructural alterations in myelin that were ongoing at the experimental time point of 35 days postinjury. We assessed the relationship between the 3 imaging modalities by multiple linear regression analysis. In this analysis, DTI and histological parameters were moderately related, whereas SμXRD parameters correlated weakly with DTI and histology. These findings suggest that while DTI appears to distinguish tissue changes at the microstructural level related to the loss of myelinated axons and gliosis, its ability to visualize alterations in myelin ultrastructure is limited. The use of several imaging techniques represents a novel approach to reveal tissue damage and provides new insights into mTBI detection.
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Affiliation(s)
| | - Michela Fratini
- Institute of Nanotechnology-CNR c/o Physics Department, Sapienza University of Rome, Rome, Italy,IRCCS Fondazione Santa Lucia, Rome, Italy
| | | | | | - Tilman A Grünewald
- European Synchrotron Radiation Facility, Grenoble Cedex, France,Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel, Marseille, France
| | - Raimo A Salo
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Omar Narvaez
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Manisha Aggarwal
- Russell H. Morgan Department of Radiology and Radiological Science, John Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jussi Tohka
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Alejandra Sierra
- Send correspondence to: Alejandra Sierra, PhD, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland (Kuopio Campus), PO Box 1627, Neulaniementie 2, FI-70211 Kuopio, Finland; E-mail:
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7
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Stem Cell Therapy for Sequestration of Traumatic Brain Injury-Induced Inflammation. Int J Mol Sci 2022; 23:ijms231810286. [PMID: 36142198 PMCID: PMC9499317 DOI: 10.3390/ijms231810286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/30/2022] [Accepted: 09/04/2022] [Indexed: 11/17/2022] Open
Abstract
Traumatic brain injury (TBI) is one of the leading causes of long-term neurological disabilities in the world. TBI is a signature disease for soldiers and veterans, but also affects civilians, including adults and children. Following TBI, the brain resident and immune cells turn into a “reactive” state, characterized by the production of inflammatory mediators that contribute to the development of cognitive deficits. Other injuries to the brain, including radiation exposure, may trigger TBI-like pathology, characterized by inflammation. Currently there are no treatments to prevent or reverse the deleterious consequences of brain trauma. The recognition that TBI predisposes stem cell alterations suggests that stem cell-based therapies stand as a potential treatment for TBI. Here, we discuss the inflamed brain after TBI and radiation injury. We further review the status of stem cells in the inflamed brain and the applications of cell therapy in sequestering inflammation in TBI.
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San Martín Molina I, Salo RA, Gröhn O, Tohka J, Sierra A. Histopathological modeling of status epilepticus-induced brain damage based on in vivo diffusion tensor imaging in rats. Front Neurosci 2022; 16:944432. [PMID: 35968364 PMCID: PMC9372371 DOI: 10.3389/fnins.2022.944432] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 07/07/2022] [Indexed: 11/13/2022] Open
Abstract
Non-invasive magnetic resonance imaging (MRI) methods have proved useful in the diagnosis and prognosis of neurodegenerative diseases. However, the interpretation of imaging outcomes in terms of tissue pathology is still challenging. This study goes beyond the current interpretation of in vivo diffusion tensor imaging (DTI) by constructing multivariate models of quantitative tissue microstructure in status epilepticus (SE)-induced brain damage. We performed in vivo DTI and histology in rats at 79 days after SE and control animals. The analyses focused on the corpus callosum, hippocampal subfield CA3b, and layers V and VI of the parietal cortex. Comparison between control and SE rats indicated that a combination of microstructural tissue changes occurring after SE, such as cellularity, organization of myelinated axons, and/or morphology of astrocytes, affect DTI parameters. Subsequently, we constructed a multivariate regression model for explaining and predicting histological parameters based on DTI. The model revealed that DTI predicted well the organization of myelinated axons (cross-validated R = 0.876) and astrocyte processes (cross-validated R = 0.909) and possessed a predictive value for cell density (CD) (cross-validated R = 0.489). However, the morphology of astrocytes (cross-validated R > 0.05) was not well predicted. The inclusion of parameters from CA3b was necessary for modeling histopathology. Moreover, the multivariate DTI model explained better histological parameters than any univariate model. In conclusion, we demonstrate that combining several analytical and statistical tools can help interpret imaging outcomes to microstructural tissue changes, opening new avenues to improve the non-invasive diagnosis and prognosis of brain tissue damage.
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Chary K, Narvaez O, Salo RA, San Martín Molina I, Tohka J, Aggarwal M, Gröhn O, Sierra A. Microstructural Tissue Changes in a Rat Model of Mild Traumatic Brain Injury. Front Neurosci 2021; 15:746214. [PMID: 34899158 PMCID: PMC8662623 DOI: 10.3389/fnins.2021.746214] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/27/2021] [Indexed: 12/31/2022] Open
Abstract
Our study investigates the potential of diffusion MRI (dMRI), including diffusion tensor imaging (DTI), fixel-based analysis (FBA) and neurite orientation dispersion and density imaging (NODDI), to detect microstructural tissue abnormalities in rats after mild traumatic brain injury (mTBI). The brains of sham-operated and mTBI rats 35 days after lateral fluid percussion injury were imaged ex vivo in a 11.7-T scanner. Voxel-based analyses of DTI-, fixel- and NODDI-based metrics detected extensive tissue changes in directly affected brain areas close to the primary injury, and more importantly, also in distal areas connected to primary injury and indirectly affected by the secondary injury mechanisms. Histology revealed ongoing axonal abnormalities and inflammation, 35 days after the injury, in the brain areas highlighted in the group analyses. Fractional anisotropy (FA), fiber density (FD) and fiber density and fiber bundle cross-section (FDC) showed similar pattern of significant areas throughout the brain; however, FA showed more significant voxels in gray matter areas, while FD and FDC in white matter areas, and orientation dispersion index (ODI) in areas most damage based on histology. Region-of-interest (ROI)-based analyses on dMRI maps and histology in selected brain regions revealed that the changes in MRI parameters could be attributed to both alterations in myelinated fiber bundles and increased cellularity. This study demonstrates that the combination of dMRI methods can provide a more complete insight into the microstructural alterations in white and gray matter after mTBI, which may aid diagnosis and prognosis following a mild brain injury.
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Affiliation(s)
- Karthik Chary
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Omar Narvaez
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Raimo A. Salo
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | | | - Jussi Tohka
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Manisha Aggarwal
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Olli Gröhn
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Alejandra Sierra
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
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10
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Algahtany M, Abdrabou A, Elhaddad A, Alghamdi A. Advances in Brain Imaging Techniques for Patients With Intractable Epilepsy. Front Neurosci 2021; 15:699123. [PMID: 34421522 PMCID: PMC8377195 DOI: 10.3389/fnins.2021.699123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 07/20/2021] [Indexed: 11/21/2022] Open
Abstract
Intractable epilepsy, also known as drug resistance or refractory epilepsy, is a major problem affecting nearly one-third of epilepsy patients. Surgical intervention could be an option to treat these patients. Correct identification and localization of epileptogenic foci is a crucial preoperative step. Some of these patients, however, have no abnormality on routine magnetic resonance imaging (MRI) of the brain. Advanced imaging techniques, therefore, can be helpful to identify the area of concern. Moreover, a clear delineation of certain anatomical brain structures and their relation to the surgical lesion or the surgical approach is essential to avoid postoperative complications, and advanced imaging techniques can be very helpful. In this review, we discuss and highlight the use of advanced imaging techniques, particularly positron emission tomography (PET)–MRI, single-photon emission computed tomography, functional MRI, and diffusion tensor imaging–tractography for the preoperative assessment of epileptic patients.
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Affiliation(s)
- Mubarak Algahtany
- Division of Neurosurgery, Department of Surgery, College of Medicine, King Khalid University, Abha, Saudi Arabia
| | - Ahmed Abdrabou
- Department of Radiology, Ain Shams University, Cairo, Egypt
| | - Ahmed Elhaddad
- Department of Radiology, Mansoura University, Mansoura, Egypt
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11
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Wiegand TLT, Sollmann N, Bonke EM, Umeasalugo KE, Sobolewski KR, Plesnila N, Shenton ME, Lin AP, Koerte IK. Translational neuroimaging in mild traumatic brain injury. J Neurosci Res 2021; 100:1201-1217. [PMID: 33789358 DOI: 10.1002/jnr.24840] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/09/2021] [Accepted: 03/17/2021] [Indexed: 01/26/2023]
Abstract
Traumatic brain injuries (TBIs) are common with an estimated 27.1 million cases per year. Approximately 80% of TBIs are categorized as mild TBI (mTBI) based on initial symptom presentation. While in most individuals, symptoms resolve within days to weeks, in some, symptoms become chronic. Advanced neuroimaging has the potential to characterize brain morphometric, microstructural, biochemical, and metabolic abnormalities following mTBI. However, translational studies are needed for the interpretation of neuroimaging findings in humans with respect to the underlying pathophysiological processes, and, ultimately, for developing novel and more targeted treatment options. In this review, we introduce the most commonly used animal models for the study of mTBI. We then summarize the neuroimaging findings in humans and animals after mTBI and, wherever applicable, the translational aspects of studies available today. Finally, we highlight the importance of translational approaches and outline future perspectives in the field of translational neuroimaging in mTBI.
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Affiliation(s)
- Tim L T Wiegand
- cBRAIN, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Ludwig-Maximilians-Universität, Munich, Germany
| | - Nico Sollmann
- cBRAIN, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Ludwig-Maximilians-Universität, Munich, Germany
- Department of Diagnostic and Interventional Neuroradiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- TUM-Neuroimaging Center, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- Department of Diagnostic and Interventional Radiology, University Hospital Ulm, Ulm, Germany
| | - Elena M Bonke
- cBRAIN, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Ludwig-Maximilians-Universität, Munich, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität, Munich, Germany
| | - Kosisochukwu E Umeasalugo
- cBRAIN, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Ludwig-Maximilians-Universität, Munich, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität, Munich, Germany
- Institute for Stroke and Dementia Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Kristen R Sobolewski
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Center for Clinical Spectroscopy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Nikolaus Plesnila
- Institute for Stroke and Dementia Research, Ludwig-Maximilians-Universität, Munich, Germany
- Munich Cluster for Systems Neurology (Synergy), Munich, Germany
| | - Martha E Shenton
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Alexander P Lin
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Center for Clinical Spectroscopy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Inga K Koerte
- cBRAIN, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Ludwig-Maximilians-Universität, Munich, Germany
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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12
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Donat CK, Yanez Lopez M, Sastre M, Baxan N, Goldfinger M, Seeamber R, Müller F, Davies P, Hellyer P, Siegkas P, Gentleman S, Sharp DJ, Ghajari M. From biomechanics to pathology: predicting axonal injury from patterns of strain after traumatic brain injury. Brain 2021; 144:70-91. [PMID: 33454735 PMCID: PMC7990483 DOI: 10.1093/brain/awaa336] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 09/01/2020] [Accepted: 09/14/2020] [Indexed: 12/19/2022] Open
Abstract
The relationship between biomechanical forces and neuropathology is key to understanding traumatic brain injury. White matter tracts are damaged by high shear forces during impact, resulting in axonal injury, a key determinant of long-term clinical outcomes. However, the relationship between biomechanical forces and patterns of white matter injuries, associated with persistent diffusion MRI abnormalities, is poorly understood. This limits the ability to predict the severity of head injuries and the design of appropriate protection. Our previously developed human finite element model of head injury predicted the location of post-traumatic neurodegeneration. A similar rat model now allows us to experimentally test whether strain patterns calculated by the model predicts in vivo MRI and histology changes. Using a controlled cortical impact, mild and moderate injuries (1 and 2 mm) were performed. Focal and axonal injuries were quantified with volumetric and diffusion 9.4 T MRI at 2 weeks post injury. Detailed analysis of the corpus callosum was conducted using multi-shell diffusion MRI and histopathology. Microglia and astrocyte density, including process parameters, along with white matter structural integrity and neurofilament expression were determined by quantitative immunohistochemistry. Linear mixed effects regression analyses for strain and strain rate with the employed outcome measures were used to ascertain how well immediate biomechanics could explain MRI and histology changes. The spatial pattern of mechanical strain and strain rate in the injured cortex shows good agreement with the probability maps of focal lesions derived from volumetric MRI. Diffusion metrics showed abnormalities in the corpus callosum, indicating white matter changes in the segments subjected to high strain, as predicted by the model. The same segments also exhibited a severity-dependent increase in glia cell density, white matter thinning and reduced neurofilament expression. Linear mixed effects regression analyses showed that mechanical strain and strain rate were significant predictors of in vivo MRI and histology changes. Specifically, strain and strain rate respectively explained 33% and 28% of the reduction in fractional anisotropy, 51% and 29% of the change in neurofilament expression and 51% and 30% of microglia density changes. The work provides evidence that strain and strain rate in the first milliseconds after injury are important factors in determining patterns of glial and axonal injury and serve as experimental validators of our computational model of traumatic brain injury. Our results provide support for the use of this model in understanding the relationship of biomechanics and neuropathology and can guide the development of head protection systems, such as airbags and helmets.
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Affiliation(s)
- Cornelius K Donat
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
- Royal British Legion Centre for Blast Injury Studies, Imperial College London, London, UK
| | - Maria Yanez Lopez
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Magdalena Sastre
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Nicoleta Baxan
- Biological Imaging Centre, Central Biomedical Services, Imperial College London, London, UK
| | - Marc Goldfinger
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Reneira Seeamber
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Franziska Müller
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Polly Davies
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Peter Hellyer
- Centre for Neuroimaging Sciences, King’s College London, London, UK
| | | | - Steve Gentleman
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - David J Sharp
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
- Royal British Legion Centre for Blast Injury Studies, Imperial College London, London, UK
- UK Dementia Research Institute, Care Research and Technology Centre; Imperial College London, London, UK
| | - Mazdak Ghajari
- Royal British Legion Centre for Blast Injury Studies, Imperial College London, London, UK
- Design Engineering, Imperial College London, UK
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13
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Pham L, Wright DK, O'Brien WT, Bain J, Huang C, Sun M, Casillas-Espinosa PM, Shah AD, Schittenhelm RB, Sobey CG, Brady RD, O'Brien TJ, Mychasiuk R, Shultz SR, McDonald SJ. Behavioral, axonal, and proteomic alterations following repeated mild traumatic brain injury: Novel insights using a clinically relevant rat model. Neurobiol Dis 2020; 148:105151. [PMID: 33127468 DOI: 10.1016/j.nbd.2020.105151] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 10/07/2020] [Accepted: 10/23/2020] [Indexed: 12/14/2022] Open
Abstract
A history of mild traumatic brain injury (mTBI) is linked to a number of chronic neurological conditions, however there is still much unknown about the underlying mechanisms. To provide new insights, this study used a clinically relevant model of repeated mTBI in rats to characterize the acute and chronic neuropathological and neurobehavioral consequences of these injuries. Rats were given four sham-injuries or four mTBIs and allocated to 7-day or 3.5-months post-injury recovery groups. Behavioral analysis assessed sensorimotor function, locomotion, anxiety, and spatial memory. Neuropathological analysis included serum quantification of neurofilament light (NfL), mass spectrometry of the hippocampal proteome, and ex vivo magnetic resonance imaging (MRI). Repeated mTBI rats had evidence of acute cognitive deficits and prolonged sensorimotor impairments. Serum NfL was elevated at 7 days post injury, with levels correlating with sensorimotor deficits; however, no NfL differences were observed at 3.5 months. Several hippocampal proteins were altered by repeated mTBI, including those associated with energy metabolism, neuroinflammation, and impaired neurogenic capacity. Diffusion MRI analysis at 3.5 months found widespread reductions in white matter integrity. Taken together, these findings provide novel insights into the nature and progression of repeated mTBI neuropathology that may underlie lingering or chronic neurobehavioral deficits.
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Affiliation(s)
- Louise Pham
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne, VIC 3086, Australia
| | - David K Wright
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - William T O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - Jesse Bain
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - Cheng Huang
- Monash Proteomics & Metabolomics Facility, Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC 3800, Australia
| | - Mujun Sun
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - Pablo M Casillas-Espinosa
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia; Department of Medicine, The University of Melbourne, Melbourne, VIC 3052, Australia
| | - Anup D Shah
- Monash Proteomics & Metabolomics Facility, Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC 3800, Australia; Monash Bioinformatics Platform, Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC 3800, Australia
| | - Ralf B Schittenhelm
- Monash Proteomics & Metabolomics Facility, Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC 3800, Australia
| | - Christopher G Sobey
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne, VIC 3086, Australia
| | - Rhys D Brady
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia; Department of Medicine, The University of Melbourne, Melbourne, VIC 3052, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia; Department of Neurology, The Alfred Hospital, Melbourne, VIC 3004, Australia; Department of Medicine, The University of Melbourne, Melbourne, VIC 3052, Australia
| | - Richelle Mychasiuk
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - Sandy R Shultz
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia; Department of Neurology, The Alfred Hospital, Melbourne, VIC 3004, Australia; Department of Medicine, The University of Melbourne, Melbourne, VIC 3052, Australia
| | - Stuart J McDonald
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne, VIC 3086, Australia; Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia.
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14
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Müller HP, Roselli F, Rasche V, Kassubek J. Diffusion Tensor Imaging-Based Studies at the Group-Level Applied to Animal Models of Neurodegenerative Diseases. Front Neurosci 2020; 14:734. [PMID: 32982659 PMCID: PMC7487414 DOI: 10.3389/fnins.2020.00734] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/22/2020] [Indexed: 12/11/2022] Open
Abstract
The understanding of human and non-human microstructural brain alterations in the course of neurodegenerative diseases has substantially improved by the non-invasive magnetic resonance imaging (MRI) technique of diffusion tensor imaging (DTI). Animal models (including disease or knockout models) allow for a variety of experimental manipulations, which are not applicable to humans. Thus, the DTI approach provides a promising tool for cross-species cross-sectional and longitudinal investigations of the neurobiological targets and mechanisms of neurodegeneration. This overview with a systematic review focuses on the principles of DTI analysis as used in studies at the group level in living preclinical models of neurodegeneration. The translational aspect from in-vivo animal models toward (clinical) applications in humans is covered as well as the DTI-based research of the non-human brains' microstructure, the methodological aspects in data processing and analysis, and data interpretation at different abstraction levels. The aim of integrating DTI in multiparametric or multimodal imaging protocols will allow the interrogation of DTI data in terms of directional flow of information and may identify the microstructural underpinnings of neurodegeneration-related patterns.
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Affiliation(s)
| | - Francesco Roselli
- Department of Neurology, University of Ulm, Ulm, Germany.,German Center for Neurodegenerative Diseases (DZNE), Ulm, Germany
| | - Volker Rasche
- Core Facility Small Animal MRI, University of Ulm, Ulm, Germany
| | - Jan Kassubek
- Department of Neurology, University of Ulm, Ulm, Germany
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