1
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Jones GMC, Cherubini GB, Llabres‐Diaz F, Caine A, De Stefani A. A case series of 37 surgically managed, paraplegic, deep pain negative French bulldogs, with thoracolumbar intervertebral disc extrusion, from two English referral centres. Vet Rec Open 2023; 10:e61. [PMID: 37181333 PMCID: PMC10170243 DOI: 10.1002/vro2.61] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 02/03/2023] [Accepted: 04/04/2023] [Indexed: 05/16/2023] Open
Abstract
Background Thoracolumbar intervertebral disc extrusions (TL-IVDEs) are a common spinal disorder in dogs, especially within chondrodystrophic breeds. Loss of deep pain perception is a well-documented negative prognostic indicator in dogs with TL-IVDE. The objectives of this study were to report the rate of return of deep pain perception and independent ambulation in surgically treated, paraplegic, deep pain perception negative French bulldogs with TL-IVDEs. Methods A retrospective case series of deep pain perception negative dogs with TL-IVDE presenting to two referral centres between 2015 and 2020 was conducted. Medical and MRI records were reviewed, including the following quantitative MRI changes: lesion length, extent of spinal cord swelling and severity of spinal cord compression. Results Thirty-seven French bulldogs met the inclusion criteria, with 14 of 37 (38%) regaining deep pain perception by the time of discharge (median hospitalisation 10.0 days [interquartile range 7.0-15.5 days]) with two dogs independently ambulatory (6%). Ten of the 37 dogs were euthanased during hospitalisation. Significantly fewer dogs (3/16, 19%) with L4-S3 lesions regained deep pain perception compared to 11 of 21 (52%) of dogs with T3-L3 lesions (p = 0.048). Quantitative MRI changes were not associated with the return of deep pain perception. After discharge, with a median 1-month follow-up period, an additional three dogs regained deep pain perception and five dogs became independently ambulatory (17/37 [46%] and 7/37 [19%], respectively). Conclusions and clinical importance This study adds support to the contention that the recovery of French bulldogs with TL-IVDE from surgery is poor compared with other breeds; further prospective, breed-controlled studies are indicated.
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Affiliation(s)
| | - Giunio Bruto Cherubini
- Dick White ReferralsStation FarmSix Mile BottomCambridgeshireUK
- Veterinary Teaching Hospital “Mario Modenato”Department of Veterinary SciencesUniversity of PisaPisaItaly
| | | | - Abby Caine
- Dick White ReferralsStation FarmSix Mile BottomCambridgeshireUK
| | - Alberta De Stefani
- Department of Clinical Science and ServicesRoyal Veterinary CollegeHertfordshireUK
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2
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Malomo T, Allard Brown A, Bale K, Yung A, Kozlowski P, Heran M, Streijger F, Kwon BK. Quantifying Intraparenchymal Hemorrhage after Traumatic Spinal Cord Injury: A Review of Methodology. J Neurotrauma 2022; 39:1603-1635. [PMID: 35538847 DOI: 10.1089/neu.2021.0317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Intraparenchymal hemorrhage (IPH) after a traumatic injury has been associated with poor neurological outcomes. Although IPH may result from the initial mechanical trauma, the blood and its breakdown products have potentially deleterious effects. Further, the degree of IPH has been correlated with injury severity and the extent of subsequent recovery. Therefore, accurate evaluation and quantification of IPH following traumatic spinal cord injury (SCI) is important to define treatments' effects on IPH progression and secondary neuronal injury. Imaging modalities, such as magnetic resonance imaging (MRI) and ultrasound (US), have been explored by researchers for the detection and quantification of IPH following SCI. Both quantitative and semiquantitative MRI and US measurements have been applied to objectively assess IPH following SCI, but the optimal methods for doing so are not well established. Studies in animal SCI models (rodent and porcine) have explored US and histological techniques in evaluating SCI and have demonstrated the potential to detect and quantify IPH. Newer techniques using machine learning algorithms (such as convolutional neural networks [CNN]) have also been studied to calculate IPH volume and have yielded promising results. Despite long-standing recognition of the potential pathological significance of IPH within the spinal cord, quantifying IPH with MRI or US is a relatively new area of research. Further studies are warranted to investigate their potential use. Here, we review the different and emerging quantitative MRI, US, and histological approaches used to detect and quantify IPH following SCI.
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Affiliation(s)
- Toluyemi Malomo
- International Collaboration on Repair Discoveries, Division of Neuroradiology, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Aysha Allard Brown
- International Collaboration on Repair Discoveries, Division of Neuroradiology, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kirsten Bale
- International Collaboration on Repair Discoveries, Division of Neuroradiology, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MRI Research Center, Division of Neuroradiology, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrew Yung
- International Collaboration on Repair Discoveries, Division of Neuroradiology, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MRI Research Center, Division of Neuroradiology, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Piotr Kozlowski
- International Collaboration on Repair Discoveries, Division of Neuroradiology, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MRI Research Center, Division of Neuroradiology, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Manraj Heran
- Department of Radiology, Division of Neuroradiology, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Femke Streijger
- International Collaboration on Repair Discoveries, Division of Neuroradiology, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Brian K Kwon
- International Collaboration on Repair Discoveries, Division of Neuroradiology, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada.,Vancouver Spine Surgery Institute, Department of Orthopaedics, and Division of Neuroradiology, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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3
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Sekiguchi N, Ito D, Ishikawa C, Tanaka N, Kitagawa M. Heavily T2-weighted imaging findings of spinal cord swelling in dogs with intervertebral disc extrusion. J S Afr Vet Assoc 2022. [DOI: 10.36303/jsava.2022.93.1.500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Affiliation(s)
- N Sekiguchi
- Laboratory of Veterinary Neurology, School of Veterinary Medicine, Nihon University,
Japan
| | - D Ito
- Laboratory of Veterinary Neurology, School of Veterinary Medicine, Nihon University,
Japan
| | - C Ishikawa
- Laboratory of Veterinary Neurology, School of Veterinary Medicine, Nihon University,
Japan
| | - N Tanaka
- Laboratory of Veterinary Neurology, School of Veterinary Medicine, Nihon University,
Japan
| | - M Kitagawa
- Laboratory of Veterinary Neurology, School of Veterinary Medicine, Nihon University,
Japan
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4
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Bendinger AL, Welzel T, Huang L, Babushkina I, Peschke P, Debus J, Glowa C, Karger CP, Saager M. DCE-MRI detected vascular permeability changes in the rat spinal cord do not explain shorter latency times for paresis after carbon ions relative to photons. Radiother Oncol 2021; 165:126-134. [PMID: 34634380 DOI: 10.1016/j.radonc.2021.09.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 09/30/2021] [Accepted: 09/30/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND PURPOSE Radiation-induced myelopathy, an irreversible complication occurring after a long symptom-free latency time, is preceded by a fixed sequence of magnetic resonance- (MR-) visible morphological alterations. Vascular degradation is assumed the main reason for radiation-induced myelopathy. We used dynamic contrast-enhanced (DCE-) MRI to identify different vascular changes after photon and carbon ion irradiation, which precede or coincide with morphological changes. MATERIALS AND METHODS The cervical spinal cord of rats was irradiated with iso-effective photon or carbon (12C-)ion doses. Afterwards, animals underwent frequent DCE-MR imaging until they developed symptomatic radiation-induced myelopathy (paresis II). Measurements were performed at certain time points: 1 month, 2 months, 3 months, 4 months, and 6 months after irradiation, and when animals showed morphological (such as edema/syrinx/contrast agent (CA) accumulation) or neurological alterations (such as, paresis I, and paresis II). DCE-MRI data was analyzed using the extended Toft's model. RESULTS Fit quality improved with gradual disintegration of the blood spinal cord barrier (BSCB) towards paresis II. Vascular permeability increased three months after photon irradiation, and rapidly escalated after animals showed MR-visible morphological changes until paresis II. After 12C-ion irradiation, vascular permeability increased when animals showed morphological alterations and increased further until animals had paresis II. The volume transfer constant and the plasma volume showed no significant changes. CONCLUSION Only after photon irradiation, DCE-MRI provides a temporal advantage in detecting early physiological signs in radiation-induced myelopathy compared to morphological MRI. As a generally lower level of vascular permeability after 12C-ions led to an earlier development of paresis as compared to photons, we conclude that other mechanisms dominate the development of paresis II.
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Affiliation(s)
- Alina L Bendinger
- Dept. of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Heidelberg Institute for Radiation Oncology (HIRO) and National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany.
| | - Thomas Welzel
- Heidelberg Institute for Radiation Oncology (HIRO) and National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany; Dept. of Radiation Oncology and Radiotherapy, University Hospital of Heidelberg, Heidelberg, Germany
| | - Lifi Huang
- Dept. of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Heidelberg Institute for Radiation Oncology (HIRO) and National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany; Faculty of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
| | - Inna Babushkina
- Core Facility Small Animal Imaging Center, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Peter Peschke
- Dept. of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Dept. of Radiation Oncology and Radiotherapy, University Hospital of Heidelberg, Heidelberg, Germany
| | - Jürgen Debus
- Dept. of Radiation Oncology and Radiotherapy, University Hospital of Heidelberg, Heidelberg, Germany; Clinical Cooperation Unit Radiation Therapy, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Christin Glowa
- Dept. of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Heidelberg Institute for Radiation Oncology (HIRO) and National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany; Dept. of Radiation Oncology and Radiotherapy, University Hospital of Heidelberg, Heidelberg, Germany
| | - Christian P Karger
- Dept. of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Heidelberg Institute for Radiation Oncology (HIRO) and National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Maria Saager
- Dept. of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Heidelberg Institute for Radiation Oncology (HIRO) and National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
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5
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Herrera J, Bockhorst K, Bhattarai D, Uray K. Gastrointestinal vascular permeability changes following spinal cord injury. Neurogastroenterol Motil 2020; 32:e13834. [PMID: 32163655 DOI: 10.1111/nmo.13834] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 02/06/2020] [Accepted: 02/18/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Gastrointestinal (GI) dysfunction is observed clinically after spinal cord injury (SCI) and contributes to the diminished long-term quality of life. Our study examined the acute and chronic GI vascular changes that occur following SCI. We demonstrated that the GI vascular tract in SCI mice becomes compromised during the acute phase of injury and persists into the chronic phase of injury. METHODS Gastrointestinal vasculature permeability was measured using dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) at 48 hours, and 2 and 4 weeks following contusion spinal cord injury. Angiopoietin-1, a vascular stabilizing protein, was administered intravenously following injury. Intestinal contractile activity assessments were performed following the last imaging session. KEY RESULTS Our results indicated that a single administration of Ang-1 reduced vascular permeability at 48 hours but the effect was only transient. However, when the treatment paradigm was changed from a single administration to multiple administrations of Ang-1 following contusion injury, our DCE MRI data indicated a significant decrease in GI vascular permeability 4 weeks after injury compared with vehicle control treated animals. This improved GI vascular permeability was associated with improved sustained intestinal contractile activity. We also demonstrated that Ang-1 reduced the expression of sICAM-1 in the ileum compared with the saline-treated group. CONCLUSIONS AND INFERENCES We show that the GI vasculature is compromised in the acute and chronic phase of injury following spinal contusion. Our results also indicate that multiple administrations of Ang-1 can attenuate GI vascular permeability, possibly reduce inflammation, and improve sustained agonist-induced contraction compared with saline treatment.
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Affiliation(s)
- Juan Herrera
- Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Kurt Bockhorst
- Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Deepa Bhattarai
- Pediatric Surgery University of Texas Medical School at Houston, Houston, Texas, USA
| | - Karen Uray
- Pediatric Surgery University of Texas Medical School at Houston, Houston, Texas, USA.,Medicinal Chemistry, University of Debrecen, Debrecen, Hungary
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6
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Zeman RJ, Wen X, Moorthy CR, Etlinger JD. Therapeutic target for external beam x-irradiation in experimental spinal cord injury. J Neurosurg Spine 2020; 32:649-656. [PMID: 31899880 DOI: 10.3171/2019.11.spine19305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 11/05/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE X-irradiation has been shown to be beneficial to recovery from spinal cord injury (SCI); however, the optimal therapeutic target has not been defined. Experiments were designed to determine the optimal target volume within the injured spinal cord for improving functional recovery and sparing tissue with stereotactic x-irradiation. METHODS SCI was produced in rats at the T10 level. A 20-Gy dose of radiation was delivered with a single, 4-mm-diameter, circular radiation beam centered either on the injury epicenter or 4 or 8 mm caudal or rostral to the injury epicenter. Locomotor function was determined for 6 weeks with the Basso, Beattie, and Bresnahan locomotor scale and tissue sparing by histological analysis of transverse sections along the spinal cords. RESULTS X-irradiation of spinal cord segments at 4 mm, but not 8 mm, caudal or rostral to the contusion epicenter resulted in increases in locomotor recovery. Consistently, significant tissue sparing also occurred with x-irradiation centered at those sites, although irradiation centered 4 mm rostral to the epicenter led to tissue sparing along the greatest length of the spinal cord. Interestingly, regression analysis of these variables demonstrated that the quantitative relationship between the amount of tissue spared and the improvement in locomotion recovery was greatest in a region several millimeters rostral to the injury epicenter. CONCLUSIONS These results indicate that x-irradiation in a region rostral to the injury epicenter is optimal for recovery from SCI. This minimal target should be attractive for therapeutic application since it allows a greatly reduced target volume so that uninjured tissue is not needlessly irradiated.
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Affiliation(s)
| | | | - Chitti R Moorthy
- 2Radiation Medicine, New York Medical College, Valhalla, New York
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7
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Siedenburg JS, Wang-Leandro A, Amendt HL, Rohn K, Tipold A, Stein VM. Transcranial magnetic motor evoked potentials and magnetic resonance imaging findings in paraplegic dogs with recovery of motor function. J Vet Intern Med 2018; 32:1116-1125. [PMID: 29566440 PMCID: PMC5980462 DOI: 10.1111/jvim.15058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 10/27/2017] [Accepted: 01/11/2018] [Indexed: 12/18/2022] Open
Abstract
Background Transcranial magnetic motor evoked potentials (TMMEP) are associated with severity of clinical signs and magnetic resonance imaging (MRI) findings in dogs with spinal cord disease. Hypothesis That in initially paraplegic dogs with thoracolumbar intervertebral disc herniation (IVDH), MRI findings before surgery and TMMEPs obtained after decompressive surgery are associated with long‐term neurological status and correlate with each other. Animals Seventeen client‐owned paraplegic dogs with acute thoracolumbar IVDH. Methods Prospective observational study. TMMEPs were obtained from pelvic limbs and MRI (3T) of the spinal cord was performed at initial clinical presentation. Follow‐up studies were performed ≤ 2 days after reappearance of motor function and 3 months later. Ratios of compression length, intramedullary hyperintensities' length (T2‐weighted hyperintensity length ratio [T2WLR]), and lesion extension (T2‐weighted‐lesion extension ratio) in relation to the length of the 2nd lumbar vertebral body were calculated. Results TMMEPs could be elicited in 10/17 (59%) dogs at 1st and in 16/17 (94%) dogs at 2nd follow‐up. Comparison of TMMEPs of 1st and 2nd follow‐up showed significantly increased amplitudes (median from 0.19 to 0.45 mV) and decreased latencies (from 69.38 to 40.26 ms; P = .01 and .001, respectively). At 2nd follow‐up latencies were significantly associated with ambulatory status (P = .024). T2WLR obtained before surgery correlated with latencies at 2nd follow‐up (P = .04). Conclusions TMMEP reflect motor function recovery after severe spinal cord injury.
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Affiliation(s)
- Johannes S Siedenburg
- Division of Neurology, Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Adriano Wang-Leandro
- Division of Neurology, Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany.,Institute of Biometry, Epidemiology, and Information Processing, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Hanna-Luise Amendt
- Division of Neurology, Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Karl Rohn
- Institute of Biometry, Epidemiology, and Information Processing, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Andrea Tipold
- Division of Neurology, Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany.,Centre of Systems Neuroscience, Hannover, Germany
| | - Veronika M Stein
- Division of Neurology, Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
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8
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De Leener B, Lévy S, Dupont SM, Fonov VS, Stikov N, Louis Collins D, Callot V, Cohen-Adad J. SCT: Spinal Cord Toolbox, an open-source software for processing spinal cord MRI data. Neuroimage 2016; 145:24-43. [PMID: 27720818 DOI: 10.1016/j.neuroimage.2016.10.009] [Citation(s) in RCA: 338] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 10/03/2016] [Accepted: 10/04/2016] [Indexed: 11/17/2022] Open
Abstract
For the past 25 years, the field of neuroimaging has witnessed the development of several software packages for processing multi-parametric magnetic resonance imaging (mpMRI) to study the brain. These software packages are now routinely used by researchers and clinicians, and have contributed to important breakthroughs for the understanding of brain anatomy and function. However, no software package exists to process mpMRI data of the spinal cord. Despite the numerous clinical needs for such advanced mpMRI protocols (multiple sclerosis, spinal cord injury, cervical spondylotic myelopathy, etc.), researchers have been developing specific tools that, while necessary, do not provide an integrative framework that is compatible with most usages and that is capable of reaching the community at large. This hinders cross-validation and the possibility to perform multi-center studies. In this study we introduce the Spinal Cord Toolbox (SCT), a comprehensive software dedicated to the processing of spinal cord MRI data. SCT builds on previously-validated methods and includes state-of-the-art MRI templates and atlases of the spinal cord, algorithms to segment and register new data to the templates, and motion correction methods for diffusion and functional time series. SCT is tailored towards standardization and automation of the processing pipeline, versatility, modularity, and it follows guidelines of software development and distribution. Preliminary applications of SCT cover a variety of studies, from cross-sectional area measures in large databases of patients, to the precise quantification of mpMRI metrics in specific spinal pathways. We anticipate that SCT will bring together the spinal cord neuroimaging community by establishing standard templates and analysis procedures.
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Affiliation(s)
- Benjamin De Leener
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - Simon Lévy
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada; Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada
| | - Sara M Dupont
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - Vladimir S Fonov
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Nikola Stikov
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada; Montreal Heart Institute, Montreal, QC, Canada
| | - D Louis Collins
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Virginie Callot
- Aix-Marseille Université, CNRS, CRMBM UMR 7339, Marseille, France; AP-HM, Hopital de la Timone, Pôle d'imagerie médicale, CEMEREM, Marseille, France
| | - Julien Cohen-Adad
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada; Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada.
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Vasconcelos NL, Gomes ED, Oliveira EP, Silva CJ, Lima R, Sousa N, Salgado AJ, Silva NA. Combining neuroprotective agents: effect of riluzole and magnesium in a rat model of thoracic spinal cord injury. Spine J 2016; 16:1015-24. [PMID: 27109831 DOI: 10.1016/j.spinee.2016.04.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 03/23/2016] [Accepted: 04/18/2016] [Indexed: 02/09/2023]
Abstract
BACKGROUND CONTEXT Damage to the spinal cord can result in irreversible impairments or complete loss of motor, sensory, and autonomic functions. Riluzole and magnesium have been widely investigated as neuroprotective agents in animal models of spinal cord injury. As these drugs protect the injured spinal cord through different mechanisms, we aimed to investigate if their neuroprotective efficacy could be cumulative. PURPOSE This study aimed to investigate the neuroprotective efficacy of combined administration of riluzole and magnesium chloride in a contusive model of thoracic spinal cord injury. STUDY DESIGN An in vivo experiment was set using female Wistar Han rats that underwent a thoracic spinal cord contusion (T8) using a weight drop method. An hour after injury, animals were randomly distributed to receive (1) saline, (2) riluzole (2.50 mg/kg), (3) magnesium chloride (24.18 mg/kg) in a polyethylene glycol formulation, or (4) a combined treatment (riluzole and magnesium). Subsequent treatments were given in four intraperitoneal injections (spaced 12 hours apart). METHODS The Basso, Beattie, and Bresnahan locomotor rating scale, an activity box test, and a swimming test were used to evaluate behavioral recovery over a 4-week period. Histologic analysis of the spinal cords was performed to measure the extent and volume of the lesion, axonal preservation, serotonergic and glutamatergic fiber sparing, motor neuron survival, and inflammation. RESULTS Our results show that only the riluzole treatment significantly improved behavioral recovery up to 4 weeks after injury when compared with saline controls (6.2±1.8), with animals achieving weight-supported stepping (9.1±1.2). Riluzole also promoted tissue sparing with significant differences achieved from 200 to 600 µm (caudally to the lesion epicenter), and reduced lesion volume, with animals presenting a significantly smaller lesion (3.23±0.26 mm(3)) when compared with the saline-treated group (4.74±0.80 mm(3)), representing a 32% decrease in lesion volume. Riluzole treatment induced significant axonal preservation, as well as serotonergic fiber sparing, caudally to the injury epicenter. CONCLUSIONS Our results suggest that the combined treatment, although simultaneously targeting two excitotoxic-related mechanisms, did not further improve behavioral and histologic outcome when compared with riluzole given alone.
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Affiliation(s)
- Natália L Vasconcelos
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Eduardo D Gomes
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Eduarda P Oliveira
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Carlos J Silva
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Rui Lima
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - António J Salgado
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Nuno A Silva
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal.
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10
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De Leener B, Taso M, Cohen-Adad J, Callot V. Segmentation of the human spinal cord. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2016; 29:125-53. [PMID: 26724926 DOI: 10.1007/s10334-015-0507-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 11/03/2015] [Accepted: 11/03/2015] [Indexed: 12/14/2022]
Abstract
Segmenting the spinal cord contour is a necessary step for quantifying spinal cord atrophy in various diseases. Delineating gray matter (GM) and white matter (WM) is also useful for quantifying GM atrophy or for extracting multiparametric MRI metrics into specific WM tracts. Spinal cord segmentation in clinical research is not as developed as brain segmentation, however with the substantial improvement of MR sequences adapted to spinal cord MR investigations, the field of spinal cord MR segmentation has advanced greatly within the last decade. Segmentation techniques with variable accuracy and degree of complexity have been developed and reported in the literature. In this paper, we review some of the existing methods for cord and WM/GM segmentation, including intensity-based, surface-based, and image-based methods. We also provide recommendations for validating spinal cord segmentation techniques, as it is important to understand the intrinsic characteristics of the methods and to evaluate their performance and limitations. Lastly, we illustrate some applications in the healthy and pathological spinal cord. One conclusion of this review is that robust and automatic segmentation is clinically relevant, as it would allow for longitudinal and group studies free from user bias as well as reproducible multicentric studies in large populations, thereby helping to further our understanding of the spinal cord pathophysiology and to develop new criteria for early detection of subclinical evolution for prognosis prediction and for patient management. Another conclusion is that at the present time, no single method adequately segments the cord and its substructure in all the cases encountered (abnormal intensities, loss of contrast, deformation of the cord, etc.). A combination of different approaches is thus advised for future developments, along with the introduction of probabilistic shape models. Maturation of standardized frameworks, multiplatform availability, inclusion in large suite and data sharing would also ultimately benefit to the community.
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Affiliation(s)
- Benjamin De Leener
- Neuroimaging Research Laboratory (NeuroPoly), Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada.,Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada
| | - Manuel Taso
- Aix Marseille Université, IFSTTAR, LBA UMR_T 24, Marseille, France.,Aix Marseille Université, CNRS, CRMBM UMR 7339, Marseille, France.,APHM, Hôpital de la Timone, Pôle d'imagerie médicale, CEMEREM, Marseille, France
| | - Julien Cohen-Adad
- Neuroimaging Research Laboratory (NeuroPoly), Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada.,Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada
| | - Virginie Callot
- Aix Marseille Université, CNRS, CRMBM UMR 7339, Marseille, France. .,APHM, Hôpital de la Timone, Pôle d'imagerie médicale, CEMEREM, Marseille, France.
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11
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Oakden W, Kwiecien JM, O'Reilly MA, Dabrowski W, Whyne C, Finkelstein J, Hynynen K, Stanisz GJ. Quantitative MRI in a non-surgical model of cervical spinal cord injury. NMR IN BIOMEDICINE 2015; 28:925-936. [PMID: 26053102 DOI: 10.1002/nbm.3326] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 04/16/2015] [Accepted: 04/19/2015] [Indexed: 06/04/2023]
Abstract
Quantitative T2 (qT2), diffusion tensor imaging (DTI), and histology were used to investigate a cervical model of spinal cord injury (SCI) in the rat. While quantitative MRI can significantly increase the specificity in the presence of pathology, it must be validated for each type of injury or disease. In the case of traumatic SCI most models are difficult to image, either due to the location of the injury, or as a result of damage to surrounding tissues resulting from invasive surgical procedures. In this study a non-surgical cervical model of SCI, produced using a combination of focused ultrasound and microbubbles, was used to produce pathology similar to that seen in models of contusive and compressive injuries. qT2 and DTI were performed at 24 h and 1 and 2 weeks following injury, and compared with H&E and luxol fast blue histology. In the injured spinal cord, in addition to intra/extracellular (I/E) water and myelin water in white matter, qT2 revealed a large component with very short T2 of about 3 ms, which was highly correlated with the presence of hemorrhage in both gray and white matter at 24 h, and with the presence of hemosiderin in gray matter at 2 weeks following injury. The T2 of the I/E water peak was also elevated at 24 h in both gray and white matter, which was correlated with the presence of vacuolation/edema on histology. Cystic cavities were only seen at the 1 or 2 week timepoints, and were correlated with the presence of a water peak with T2 > 250 ms. No significant changes in diffusivity parameters were observed. Pathologies were often co-occurring, with opposite effects on the average T2 in a given voxel, reducing the visibility of injured tissue on standard T2 -weighted MR images.
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Affiliation(s)
- Wendy Oakden
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Jacek M Kwiecien
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Meaghan A O'Reilly
- Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Wojciech Dabrowski
- Department of Anaesthesiology and Intensive Therapy, Medical University of Lublin, Lublin, Poland
| | - Cari Whyne
- Orthopaedic Biomechanics Laboratory, Sunnybrook Research Institute, Toronto, Ontario, Canada
- Division of Orthopaedics, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - Joel Finkelstein
- Division of Orthopaedics, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
- Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Kullervo Hynynen
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Greg J Stanisz
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
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12
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Lévy S, Benhamou M, Naaman C, Rainville P, Callot V, Cohen-Adad J. White matter atlas of the human spinal cord with estimation of partial volume effect. Neuroimage 2015; 119:262-71. [PMID: 26099457 DOI: 10.1016/j.neuroimage.2015.06.040] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 05/24/2015] [Accepted: 06/13/2015] [Indexed: 12/14/2022] Open
Abstract
Template-based analysis has proven to be an efficient, objective and reproducible way of extracting relevant information from multi-parametric MRI data. Using common atlases, it is possible to quantify MRI metrics within specific regions without the need for manual segmentation. This method is therefore free from user-bias and amenable to group studies. While template-based analysis is common procedure for the brain, there is currently no atlas of the white matter (WM) spinal pathways. The goals of this study were: (i) to create an atlas of the white matter tracts compatible with the MNI-Poly-AMU template and (ii) to propose methods to quantify metrics within the atlas that account for partial volume effect. The WM atlas was generated by: (i) digitalizing an existing WM atlas from a well-known source (Gray's Anatomy), (ii) registering this atlas to the MNI-Poly-AMU template at the corresponding slice (C4 vertebral level), (iii) propagating the atlas throughout all slices of the template (C1 to T6) using regularized diffeomorphic transformations and (iv) computing partial volume values for each voxel and each tract. Several approaches were implemented and validated to quantify metrics within the atlas, including weighted-average and Gaussian mixture models. Proof-of-concept application was done in five subjects for quantifying magnetization transfer ratio (MTR) in each tract of the atlas. The resulting WM atlas showed consistent topological organization and smooth transitions along the rostro-caudal axis. The median MTR across tracts was 26.2. Significant differences were detected across tracts, vertebral levels and subjects, but not across laterality (right-left). Among the different tested approaches to extract metrics, the maximum a posteriori showed highest performance with respect to noise, inter-tract variability, tract size and partial volume effect. This new WM atlas of the human spinal cord overcomes the biases associated with manual delineation and partial volume effect. Combined with multi-parametric data, the atlas can be applied to study demyelination and degeneration in diseases such as multiple sclerosis and will facilitate the conduction of longitudinal and multi-center studies.
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Affiliation(s)
- S Lévy
- Neuroimaging Research Laboratory (NeuroPoly), Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada; Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada
| | - M Benhamou
- Neuroimaging Research Laboratory (NeuroPoly), Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - C Naaman
- Neuroimaging Research Laboratory (NeuroPoly), Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - P Rainville
- Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada; Department of Stomatology, Université de Montréal, Montreal, QC, Canada
| | - V Callot
- Aix-Marseille Université (AMU), CNRS, CRMBM UMR 7339, 13385 Marseille, France; APHM, Hôpital de la Timone, CEMEREM, 13005 Marseille, France
| | - J Cohen-Adad
- Neuroimaging Research Laboratory (NeuroPoly), Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada; Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada.
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13
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Yu H, Lin B, He Y, Zhang W, Xu Y. Batroxobin protects against spinal cord injury in rats by promoting the expression of vascular endothelial growth factor to reduce apoptosis. Exp Ther Med 2015; 9:1631-1638. [PMID: 26136870 DOI: 10.3892/etm.2015.2368] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Accepted: 03/03/2015] [Indexed: 01/19/2023] Open
Abstract
The host response to spinal cord injury (SCI) can lead to an ischemic environment that can induce cell death. Therapeutic interventions using neurotrophic factors have focused on the prevention of such reactions in order to reduce this cell death. Vascular endothelial growth factor (VEGF) is a potent angiogenic and vascular permeability factor. We hypothesized in this study that batroxobin would exhibit protective effects following SCI by promoting the expression of VEGF to reduce the levels of apoptosis in a rat model of SCI. Ninety adult female Sprague Dawley rats were divided randomly into sham injury (group I), SCI (group II) and batroxobin treatment (group III) groups. The Basso-Bettie-Bresnahan (BBB) scores, number of apoptotic cells and expression of VEGF were assessed at 1, 3, 5, 7, 14 and 28 days post-injury. The BBB scores were significantly improved in group III compared with those in group II between days 5 and 28 post-injury (P<0.05). At each time-point subsequent to the injury, the number of apoptotic cells in group III was reduced compared with that in group II. Compared with group II, treatment with batroxobin significantly increased the expression of VEGF from day 3 until 2 weeks post-SCI (P<0.05), while no significant difference was observed at day 28. These data suggest that batroxobin has multiple beneficial effects on SCI, indicating a potential clinical application.
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Affiliation(s)
- Hui Yu
- Department of Orthopedics, The 175th Hospital of the PLA, Southeast Hospital of Xiamen University, Zhangzhou, Fujian 363000, P.R. China
| | - Bin Lin
- Department of Orthopedics, The 175th Hospital of the PLA, Southeast Hospital of Xiamen University, Zhangzhou, Fujian 363000, P.R. China
| | - Yongzhi He
- Department of Orthopedics, The 175th Hospital of the PLA, Southeast Hospital of Xiamen University, Zhangzhou, Fujian 363000, P.R. China
| | - Wenbin Zhang
- Department of Orthopedics, The 175th Hospital of the PLA, Southeast Hospital of Xiamen University, Zhangzhou, Fujian 363000, P.R. China
| | - Yang Xu
- Department of Orthopedics, The 175th Hospital of the PLA, Southeast Hospital of Xiamen University, Zhangzhou, Fujian 363000, P.R. China
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14
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Wang F, Qi HX, Zu Z, Mishra A, Tang C, Gore JC, Chen LM. Multiparametric MRI reveals dynamic changes in molecular signatures of injured spinal cord in monkeys. Magn Reson Med 2014; 74:1125-37. [PMID: 25334025 DOI: 10.1002/mrm.25488] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 08/08/2014] [Accepted: 09/17/2014] [Indexed: 11/06/2022]
Abstract
PURPOSE To monitor the spontaneous recovery of cervical spinal cord injury (SCI) using longitudinal multiparametric MRI methods. METHODS Quantitative MRI imaging including diffusion tensor imaging, magnetization transfer (MT), and chemical exchange saturation transfer (CEST) were conducted in anesthetized squirrel monkeys at 9.4T. The structural, cellular, and molecular features of the spinal cord were examined before and at different time points after a dorsal column lesion in each monkey. RESULTS Images with MT contrast enhanced visualization of the gray and white matter boundaries and the lesion and permitted differentiation of core and rim compartments within an abnormal volume (AV). In the early weeks after SCI, both core and rim exhibited low cellular density and low protein content, with high levels of exchanging hydroxyl, amine, and amide protons, as evidenced by increased apparent diffusion coefficient, decreased fractional anisotropy, decreased MT ratio, decreased nuclear Overhauser effect, and large CEST effects. Over time, cellular density and fiber density increased, whereas amide, amine, and hydroxyl levels dropped significantly, but at differing rates. Histology confirmed the nature of the AV to be a cyst. CONCLUSION Multiparametric MRI offers a novel method to quantify the spontaneous changes in structure and cellular and molecular compositions of SC during spontaneous recovery from injury.
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Affiliation(s)
- Feng Wang
- Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Hui-Xin Qi
- Department of Psychology, Vanderbilt University, Nashville, Tennessee, USA
| | - Zhongliang Zu
- Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Arabinda Mishra
- Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Chaohui Tang
- Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - John C Gore
- Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA.,Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Li Min Chen
- Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA.,Department of Psychology, Vanderbilt University, Nashville, Tennessee, USA
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15
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Shinozaki M, Nakamura M, Konomi T, Kobayashi Y, Takano M, Saito N, Toyama Y, Okano H. Distinct roles of endogenous vascular endothelial factor receptor 1 and 2 in neural protection after spinal cord injury. Neurosci Res 2013; 78:55-64. [PMID: 24107617 DOI: 10.1016/j.neures.2013.09.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 09/09/2013] [Accepted: 09/17/2013] [Indexed: 01/19/2023]
Abstract
Secondary degeneration after spinal cord injury (SCI) is caused by increased vascular permeability, infiltration of inflammatory cells, and subsequent focal edema. Therapeutic interventions using neurotrophic factors have focused on the prevention of such reactions to reduce cell death and promote tissue regeneration. Vascular endothelial growth factor (VEGF) is a potent angiogenic and vascular permeability factor. However, the effect of VEGF on SCI remains controversial. VEGF signaling is primarily regulated through two primary receptors, VEGF receptor 1 (VEGF-R1) and VEGF receptor 2 (VEGF-R2). The purpose of this study was to examine the effects of intraperitoneal administration of VEGF-R1- and VEGF-R2-neutralizing antibodies on a mouse model of SCI. VEGF-R1 blockade, but not VEGF-R2 blockade, decreased the permeability and infiltration of inflammatory cells, and VEGF-R2 blockade caused a significant increase in neuronal apoptosis in the acute phase of SCI. VEGF-R2 blockade decreased the residual tissue area and the number of neural fibers in the chronic phase of SCI. VEGF-R2 blockade worsened the functional recovery and prolonged the latency of motor evoked potentials. These data suggest that endogenous VEGF-R2 plays a crucial role in neuronal protection after SCI.
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Affiliation(s)
- Munehisa Shinozaki
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Masaya Nakamura
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
| | - Tsunehiko Konomi
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Yoshiomi Kobayashi
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Morito Takano
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Nobuhito Saito
- Department of Neurosurgery, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Yoshiaki Toyama
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
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16
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Russell KL, Berman NEJ, Levant B. Low brain DHA content worsens sensorimotor outcomes after TBI and decreases TBI-induced Timp1 expression in juvenile rats. Prostaglandins Leukot Essent Fatty Acids 2013; 89:97-105. [PMID: 23796971 PMCID: PMC3753049 DOI: 10.1016/j.plefa.2013.05.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 05/22/2013] [Accepted: 05/23/2013] [Indexed: 12/31/2022]
Abstract
The effects of dietary modulation of brain DHA content on outcomes after TBI were examined in a juvenile rat model. Long-Evans rats with normal or diet-induced decreases in brain DHA were subjected to a controlled cortical impact or sham surgery on postnatal day 17. Rats with the greatest decreases in brain DHA had the poorest sensorimotor outcomes after TBI. Ccl2, Gfap, and Mmp 9 mRNA levels, and MMP-2 and -9 enzymatic activities were increased after TBI regardless of brain DHA level. Lesion volume was not affected by brain DHA level. In contrast, TBI-induced Timp1 expression was lower in rats on the Deficient diet and correlated with brain DHA level. These data suggest that decreased brain DHA content contributes to poorer sensorimotor outcomes after TBI through a mechanism involving modulation of Timp1 expression.
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Affiliation(s)
- Kristin L. Russell
- Department of Pharmacology, Toxicology, and Therapeutics, 3901 Rainbow Blvd., University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Nancy E. J. Berman
- Department of Anatomy & Cell Biology, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160 USA
| | - Beth Levant
- Department of Pharmacology, Toxicology, and Therapeutics, 3901 Rainbow Blvd., University of Kansas Medical Center, Kansas City, KS 66160 USA
- Corresponding author: Department of Pharmacology, University of Kansas Medical Center, Mail Stop 1018, 3901 Rainbow Blvd., Kansas City, KS 66160, Phone: 1 913 588 7527, Fax: 1 913 588 7501,
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17
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Rao JS, Zhao C, Yang ZY, Li SY, Jiang T, Fan YB, Li XG. Diffusion tensor tractography of residual fibers in traumatic spinal cord injury: a pilot study. J Neuroradiol 2013; 40:181-6. [PMID: 23428240 DOI: 10.1016/j.neurad.2012.08.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 08/01/2012] [Accepted: 08/23/2012] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND PURPOSE In clinical studies, evaluating residual fiber tracts in spinal cord injuries poses serious difficulties, whereas diffusion tensor imaging (DTI) can assess alterations in fiber structural integrity. For this reason, this study aimed to determine changes in the structural integrity of residual fiber tracts via fractional anisotropy (FA) variations and fiber-tracking patterns in patients with chronic traumatic spinal cord injury (SCI). MATERIALS AND METHODS T2-weighted and diffusion-weighted imaging was performed on four traumatic SCI patients and three healthy volunteers using a 3.0-T MR scanner. After obtaining fiber-tracking maps, FA values were measured and analyzed in residual and remote normal and healthy cords. RESULTS Diffusion tensor tractography showed obvious destruction of fiber tracts in injured cords. In the healthy control subjects, averaged FA values ranged from 0.545 to 0.601, whereas all SCI patients had decreased FA values in both residual (0.220 ± 0.121) and remote normal fibers (0.535 ± 0.101). There were also statistically significant differences in FA values between residual and remote normal fibers in patients (P = 0.000) and between their residual and healthy control fibers (P = 0.000). No significant difference was found between remote normal and healthy cords (P = 0.312). CONCLUSION Specific FA variations were observed in residual fibers, suggesting that DTI may be a useful tool for evaluating residual tracts in SCI patients.
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Affiliation(s)
- Jia-Sheng Rao
- Department of Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, 37# Xueyuan Road, 100191 Beijing, China
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18
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Lee P, Kim J, Williams R, Sandhir R, Gregory E, Brooks WM, Berman NEJ. Effects of aging on blood brain barrier and matrix metalloproteases following controlled cortical impact in mice. Exp Neurol 2011; 234:50-61. [PMID: 22201549 DOI: 10.1016/j.expneurol.2011.12.016] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 12/05/2011] [Accepted: 12/09/2011] [Indexed: 11/18/2022]
Abstract
Aging alters the ability of the brain to respond to injury. One of the major differences between the adult and aged brain is that comparable injuries lead to greater blood brain barrier disruption in the aged brain. The goals of these studies were to quantify the effects of age on BBB permeability using high field strength MRI T1 mapping and to determine whether activation of matrix metalloproteases, their inhibitors, or expression of blood brain barrier structural proteins, occludin, zonnula occludins-1 (ZO-1) and claudin-5 were altered following injury to the aged C57/BL6 mouse brain. T1 mapping studies revealed greater blood brain barrier permeability in the aged (21-24 months old) brain than in the adult (4-6 months old) following controlled cortical impact. The increased blood brain barrier permeability in the pericontusional region was confirmed with IgG immunohistochemistry. MMP-9 activity was increased following controlled cortical impact in the aged brain, and this was accompanied by increased MMP-9 gene expression. MMP-2 activity was higher in the uninjured aged brain than in the adult brain. Occludin and ZO-1 mRNA levels were unchanged following injury in either age group, but claudin-5 mRNA levels were lower in the aged than the adult brain following injury. These results demonstrate quantitative increases in blood brain barrier permeability in the aged brain following injury that are accompanied by increased MMP-9 activation and decreased blood brain barrier repair responses.
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Affiliation(s)
- Phil Lee
- Hoglund Brain Imaging Center, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
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19
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Russell KL, Kutchko KM, Fowler SC, Berman NEJ, Levant B. Sensorimotor behavioral tests for use in a juvenile rat model of traumatic brain injury: assessment of sex differences. J Neurosci Methods 2011; 199:214-22. [PMID: 21600923 DOI: 10.1016/j.jneumeth.2011.05.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 04/29/2011] [Accepted: 05/04/2011] [Indexed: 12/23/2022]
Abstract
Modeling juvenile traumatic brain injury (TBI) in rodents presents several unique challenges compared to adult TBI, one of which is selecting appropriate sensorimotor behavioral tasks that enable the assessment of the extent of injury and recovery over time in developing animals. To address this challenge, we performed a comparison of common sensorimotor tests in Long-Evans rats of various sizes and developmental stages (postnatal days 16-45, 35-190 g). Tests were compared and selected for their developmental appropriateness, scalability for growth, pre-training requirements, and throughput capability. Sex differences in response to TBI were also assessed. Grid walk, automated gait analysis, rotarod, beam walk, spontaneous forelimb elevation test, and measurement of motor activity using the force-plate actometer were evaluated. Grid walk, gait analysis, and rotarod failed to meet one or more of the evaluation criteria. Beam walk, spontaneous forelimb elevation test, and measurement of motor activity using the force-plate actometer satisfied all criteria and were capable of detecting motor abnormalities in rats subjected to controlled cortical impact on postnatal day 17. No sex differences were detected in the acute effects of TBI or functional recovery during the 28 days after injury using these tests. This demonstrates the utility of these tests for the evaluation of sensorimotor function in studies using rat models of pediatric TBI, and suggests that pre-pubertal males and females respond similarly to TBI with respect to sensorimotor outcomes.
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Affiliation(s)
- Kristin L Russell
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA.
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20
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Pillai DR, Heidemann RM, Kumar P, Shanbhag N, Lanz T, Dittmar MS, Sandner B, Beier CP, Weidner N, Greenlee MW, Schuierer G, Bogdahn U, Schlachetzki F. Comprehensive small animal imaging strategies on a clinical 3 T dedicated head MR-scanner; adapted methods and sequence protocols in CNS pathologies. PLoS One 2011; 6:e16091. [PMID: 21326876 PMCID: PMC3034718 DOI: 10.1371/journal.pone.0016091] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 12/09/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Small animal models of human diseases are an indispensable aspect of pre-clinical research. Being dynamic, most pathologies demand extensive longitudinal monitoring to understand disease mechanisms, drug efficacy and side effects. These considerations often demand the concomitant development of monitoring systems with sufficient temporal and spatial resolution. METHODOLOGY AND RESULTS This study attempts to configure and optimize a clinical 3 Tesla magnetic resonance scanner to facilitate imaging of small animal central nervous system pathologies. The hardware of the scanner was complemented by a custom-built, 4-channel phased array coil system. Extensive modification of standard sequence protocols was carried out based on tissue relaxometric calculations. Proton density differences between the gray and white matter of the rodent spinal cord along with transverse relaxation due to magnetic susceptibility differences at the cortex and striatum of both rats and mice demonstrated statistically significant differences. The employed parallel imaging reconstruction algorithms had distinct properties dependent on the sequence type and in the presence of the contrast agent. The attempt to morphologically phenotype a normal healthy rat brain in multiple planes delineated a number of anatomical regions, and all the clinically relevant sequels following acute cerebral ischemia could be adequately characterized. Changes in blood-brain-barrier permeability following ischemia-reperfusion were also apparent at a later time. Typical characteristics of intra-cerebral haemorrhage at acute and chronic stages were also visualized up to one month. Two models of rodent spinal cord injury were adequately characterized and closely mimicked the results of histological studies. In the employed rodent animal handling system a mouse model of glioblastoma was also studied with unequivocal results. CONCLUSIONS The implemented customizations including extensive sequence protocol modifications resulted in images of high diagnostic quality. These results prove that lack of dedicated animal scanners shouldn't discourage conventional small animal imaging studies.
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Affiliation(s)
- Deepu R. Pillai
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
- Department of Genetics and Neurobiology, Biozentrum, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Robin M. Heidemann
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Siemens Healthcare Sector, Erlangen, Germany
| | - Praveen Kumar
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
- Department of Neurology, University Medical Centre, RWTH Aachen, Aachen, Germany
| | - Nagesh Shanbhag
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
| | - Titus Lanz
- RAPID Biomedical GmbH, Würzburg-Rimpar, Germany
| | - Michael S. Dittmar
- Department of Anaesthesiology, Regensburg University Medical Centre, Regensburg, Germany
| | - Beatrice Sandner
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
| | - Christoph P. Beier
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
- Department of Neurology, University Medical Centre, RWTH Aachen, Aachen, Germany
| | - Norbert Weidner
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
- Institute for Paraplegia, University of Heidelberg, Heidelberg, Germany
| | - Mark W. Greenlee
- Institute for Experimental Psychology, University of Regensburg, Regensburg, Germany
| | - Gerhard Schuierer
- Center for Neuroradiology, Regensburg University Medical Centre and Bezirksklinikum Regensburg, Regensburg, Germany
| | - Ulrich Bogdahn
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
| | - Felix Schlachetzki
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
- * E-mail:
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21
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Byrnes KR, Fricke ST, Faden AI. Neuropathological differences between rats and mice after spinal cord injury. J Magn Reson Imaging 2011; 32:836-46. [PMID: 20882614 DOI: 10.1002/jmri.22323] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To investigate the utility of noninvasive magnetic resonance imaging (MRI) protocols to demonstrate pathological differences between rats and mice after spinal cord injury (SCI). Rats and mice are commonly used to model SCI; however, histology and immunohistochemistry have shown differences in neuropathology between the two species, including cavity formation and scar/inflammatory responses. MATERIALS AND METHODS Moderate contusion SCI was performed on adult male rats and mice. At 28 days postinjury, animals underwent T1-weighted (T1W), with or without gadolinium contrast, or T2-weighted (T2W) magnetic resonance imaging (MRI), to be compared with histology at the same timepoint. RESULTS In both species, all MRI methods demonstrated changes in spinal cord anatomy. Immunohistochemistry indicated that T2W accurately reflected areas of inflammation and glial scar formation in rats and mice. Quantitation of lesion volume by histology and functional performance correlated best with T2W measurements in both species. Gadolinium contrast accurately reflected the blood-spinal cord-barrier permeability in both species, which appeared greater in rats than in mice. CONCLUSION These data demonstrate that MRI, with either a T1W or T2W protocol, can effectively distinguish pathological differences between rats and mice.
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Affiliation(s)
- Kimberly R Byrnes
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC, USA
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Erschbamer M, Oberg J, Westman E, Sitnikov R, Olson L, Spenger C. 1H-MRS in spinal cord injury: acute and chronic metabolite alterations in rat brain and lumbar spinal cord. Eur J Neurosci 2011; 33:678-88. [PMID: 21251091 PMCID: PMC3072523 DOI: 10.1111/j.1460-9568.2010.07562.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A variety of tests of sensorimotor function are used to characterize outcome after experimental spinal cord injury (SCI). These tests typically do not provide information about chemical and metabolic processes in the injured CNS. Here, we used (1) H-magnetic resonance spectroscopy (MRS) to monitor long-term and short-term chemical changes in the CNS in vivo following SCI. The investigated areas were cortex, thalamus/striatum and the spinal cord distal to injury. In cortex, glutamate (Glu) decreased 1 day after SCI and slowly returned towards normal levels. The combined glutamine (Gln) and Glu signal was similarly decreased in cortex, but increased in the distal spinal cord, suggesting opposite changes of the Glu/Gln metabolites in cortex and distal spinal cord. In lumbar spinal cord, a marked increase of myo-inositol was found 3 days, 14 days and 4 months after SCI. Changes in metabolite concentrations in the spinal cord were also found for choline and N-acetylaspartate. No significant changes in metabolite concentrations were found in thalamus/striatum. Multivariate data analysis allowed separation between rats with SCI and controls for spectra acquired in cortex and spinal cord, but not in thalamus/striatum. Our findings suggest MRS could become a helpful tool to monitor spatial and temporal alterations of metabolic conditions in vivo in the brain and spinal cord after SCI. We provide evidence for dynamic temporal changes at both ends of the neuraxis, cortex cerebri and distal spinal cord, while deep brain areas appear less affected.
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Affiliation(s)
- Matthias Erschbamer
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, SE-171 77 Stockholm, Sweden
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Abstract
Different MR techniques, such as relaxation times, diffusion, perfusion, and spectroscopy have been employed to study rodent spinal cord. In this chapter, a description of these methods is given, along with examples of normal metrics that can be derived from the MR acquisitions, as well as examples of applications to pathology.
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Affiliation(s)
- Virginie Callot
- Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR 6612, CNRS, Université de la Méditerranée, 13385 Marseille Cedex 05, France.
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Sundberg LM, Herrera JJ, Narayana PA. In vivo longitudinal MRI and behavioral studies in experimental spinal cord injury. J Neurotrauma 2010; 27:1753-67. [PMID: 20649481 DOI: 10.1089/neu.2010.1369] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Comprehensive in vivo longitudinal studies that include multi-modal magnetic resonance imaging (MRI) and a battery of behavioral assays to assess functional outcome were performed at multiple time points up to 56 days post-traumatic spinal cord injury (SCI) in rodents. The MRI studies included high-resolution structural imaging for lesion volumetry, and diffusion tensor imaging (DTI) for probing the white matter integrity. The behavioral assays included open-field locomotion, grid walking, inclined plane, computerized activity box performance, and von Frey filament tests. Additionally, end-point histology was assessed for correlation with both the MRI and behavioral data. The temporal patterns of the lesions were documented on structural MRI. DTI studies showed significant changes in white matter that is proximal to the injury epicenter and persisted to day 56. White matter in regions up to 1 cm away from the injury epicenter that appeared normal on conventional MRI also exhibited changes that were indicative of tissue damage, suggesting that DTI is a more sensitive measure of the evolving injury. Correlations between DTI and histology after SCI could not be firmly established, suggesting that injury causes complex pathological changes in multiple tissue components that affect the DTI measures. Histological evidence confirmed a significant decrease in myelin and oligodendrocyte presence 56 days post-SCI. Multiple assays to evaluate aspects of functional recovery correlated with histology and DTI measures, suggesting that damage to specific white matter tracts can be assessed and tracked longitudinally after SCI.
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Affiliation(s)
- Laura M Sundberg
- Department of Diagnostic and Interventional Imaging, The University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
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Patel CB, Cohen DM, Ahobila-Vajjula P, Sundberg LM, Chacko T, Narayana PA. Effect of VEGF treatment on the blood-spinal cord barrier permeability in experimental spinal cord injury: dynamic contrast-enhanced magnetic resonance imaging. J Neurotrauma 2010; 26:1005-16. [PMID: 19226205 DOI: 10.1089/neu.2008.0860] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Compromised blood-spinal cord barrier (BSCB) is a factor in the outcome following traumatic spinal cord injury (SCI). Vascular endothelial growth factor (VEGF) is a potent stimulator of angiogenesis and vascular permeability. The role of VEGF in SCI is controversial. Relatively little is known about the spatial and temporal changes in the BSCB permeability following administration of VEGF in experimental SCI. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) studies were performed to noninvasively follow spatial and temporal changes in the BSCB permeability following acute administration of VEGF in experimental SCI over a post-injury period of 56 days. The DCE-MRI data was analyzed using a two-compartment pharmacokinetic model. Animals were assessed for open field locomotion using the Basso-Beattie-Bresnahan score. These studies demonstrate that the BSCB permeability was greater at all time points in the VEGF-treated animals compared to saline controls, most significantly in the epicenter region of injury. Although a significant temporal reduction in the BSCB permeability was observed in the VEGF-treated animals, BSCB permeability remained elevated even during the chronic phase. VEGF treatment resulted in earlier improvement in locomotor ability during the chronic phase of SCI. This study suggests a beneficial role of acutely administered VEGF in hastening neurobehavioral recovery after SCI.
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Affiliation(s)
- Chirag B Patel
- Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, Houston, Texas 77030, USA
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Ellingson BM, Schmit BD, Kurpad SN. Lesion growth and degeneration patterns measured using diffusion tensor 9.4-T magnetic resonance imaging in rat spinal cord injury. J Neurosurg Spine 2010; 13:181-92. [PMID: 20672953 DOI: 10.3171/2010.3.spine09523] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECT Using diffusion tensor MR imaging, the authors conducted a study to explore lesion growth and degeneration patterns, from the acute through chronic stages of spinal cord injury (SCI), in an experimental animal model. METHODS In vivo and ex vivo diffusion tensor imaging was performed using a 9.4-T MR imaging system in rats allowed to recover from traumatic contusion SCI from 2 weeks through 25 weeks postinjury, mimicking progression of human SCI from the acute through chronic stages. RESULTS Results showed significant growth of the traumatic lesion up to 15 weeks postinjury, where both the size and mean diffusivity (MD) reached a maximum that was maintained through the remainder of recovery. Mean diffusivity was sensitive to overall spinal cord integrity, whereas fractional anisotropy showed specificity to sites of cavity formation. The use of an MD contour map for in vivo data and a 3D surface map for ex vivo data, showing MD as a function of rostral-caudal distance and recovery time, allowed documentation of rostral and caudal spreading of the lesion. CONCLUSIONS Results from this study demonstrate changes in both lesion morphology and diffusivity beyond previously reported time points and provide a unique perspective on the process of cavity formation and degeneration following traumatic SCI. Additionally, results suggest that MD more accurately defines regions of histological damage than do regions of T2 signal hyperintensity. This could have significant clinical implications in the detection and potential treatment of posttraumatic syringes in SCI.
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Affiliation(s)
- Benjamin M Ellingson
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin 53201, USA
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Ek CJ, Habgood MD, Callaway JK, Dennis R, Dziegielewska KM, Johansson PA, Potter A, Wheaton B, Saunders NR. Spatio-temporal progression of grey and white matter damage following contusion injury in rat spinal cord. PLoS One 2010; 5:e12021. [PMID: 20711496 PMCID: PMC2918504 DOI: 10.1371/journal.pone.0012021] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Accepted: 07/12/2010] [Indexed: 12/20/2022] Open
Abstract
Cellular mechanisms of secondary damage progression following spinal cord injury remain unclear. We have studied the extent of tissue damage from 15 min to 10 weeks after injury using morphological and biochemical estimates of lesion volume and surviving grey and white matter. This has been achieved by semi-quantitative immunocytochemical methods for a range of cellular markers, quantitative counts of white matter axonal profiles in semi-thin sections and semi-quantitative Western blot analysis, together with behavioural tests (BBB scores, ledged beam, random rung horizontal ladder and DigiGait™ analysis). We have developed a new computer-controlled electronic impactor based on a linear motor that allows specification of the precise nature, extent and timing of the impact. Initial (15 min) lesion volumes showed very low variance (1.92±0.23 mm3, mean±SD, n = 5). Although substantial tissue clearance continued for weeks after injury, loss of grey matter was rapid and complete by 24 hours, whereas loss of white matter extended up to one week. No change was found between one and 10 weeks after injury for almost all morphological and biochemical estimates of lesion size or behavioural methods. These results suggest that previously reported apparent ongoing injury progression is likely to be due, to a large extent, to clearance of tissue damaged by the primary impact rather than continuing cell death. The low variance of the impactor and the comprehensive assessment methods described in this paper provide an improved basis on which the effects of potential treatment regimes for spinal cord injury can be assessed.
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Affiliation(s)
- C. Joakim Ek
- Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia
| | - Mark D. Habgood
- Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia
| | - Jennifer K. Callaway
- Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia
| | - Ross Dennis
- Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia
| | | | - Pia A. Johansson
- Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia
| | - Ann Potter
- Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia
| | - Benjamin Wheaton
- Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia
| | - Norman R. Saunders
- Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
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Qian J, Herrera JJ, Narayana PA. Neuronal and axonal degeneration in experimental spinal cord injury: in vivo proton magnetic resonance spectroscopy and histology. J Neurotrauma 2010; 27:599-610. [PMID: 20001674 DOI: 10.1089/neu.2009.1145] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Longitudinal in vivo proton magnetic resonance spectroscopy (1H-MRS) and immunohistochemistry were performed to investigate the tissue degeneration in traumatically injured rat spinal cord rostral and caudal to the lesion epicenter. On 1H-MRS significant decreases in N-acetyl aspartate (NAA) and total creatine (Cr) levels in the rostral, epicenter, and caudal segments were observed by 14 days, and levels remained depressed up to 56 days post-injury (PI). In contrast, the total choline (Cho) levels increased significantly in all three segments by 14 days PI, but recovered in the epicenter and caudal, but not the rostral region, at 56 days PI. Immunohistochemistry demonstrated neuronal cell death in the gray matter, and reactive astrocytes and axonal degeneration in the dorsal, lateral, and ventral white-matter columns. These results suggest delayed tissue degeneration in regions both rostrally and caudally from the epicenter in the injured spinal cord tissue. A rostral-caudal asymmetry in tissue recovery was seen both on MRI-observed hyperintense lesion volume and the Cho, but not NAA and Cr, levels at 56 days PI. These studies suggest that dynamic metabolic changes take place in regions away from the epicenter in injured spinal cord.
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Affiliation(s)
- Junchao Qian
- Department of Diagnostic and Interventional Imaging, The University of Texas Medical School at Houston, Houston, Texas 77030, USA
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Duhamel G, Callot V, Decherchi P, Le Fur Y, Marqueste T, Cozzone PJ, Kober F. Mouse lumbar and cervical spinal cord blood flow measurements by arterial spin labeling: Sensitivity optimization and first application. Magn Reson Med 2009; 62:430-9. [DOI: 10.1002/mrm.22015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Hypertonic saline attenuates cord swelling and edema in experimental spinal cord injury: a study utilizing magnetic resonance imaging. Crit Care Med 2009; 37:2160-6. [PMID: 19487936 DOI: 10.1097/ccm.0b013e3181a05d41] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE To use magnetic resonance imaging (MRI) to characterize secondary injury immediately after spinal cord injury (SCI), and to show the effect of hypertonic saline on MRI indices of swelling, edema, and hemorrhage within the cord. DESIGN A prospective, randomized, placebo-controlled study. SETTING Research laboratory. SUBJECTS Twelve adult Long-Evans female rats. INTERVENTIONS Rats underwent a unilateral 12.5 mm SCI at vertebral level C5. Animals were administered 0.9% NaCl (n = 6) or 5% NaCl (n = 6) at 1.4 mL/kg intravenously every hour starting 30 minutes after SCI. Immediately after SCI, rats were placed in a 4.7T Bruker MRI system and images were obtained continuously for 8 hours using a home-built transmitter/receiver 3 cm Helmholtz coil. Rats were killed 8 hours after SCI. MEASUREMENTS AND MAIN RESULTS Quantification of cord swelling and volumes of hypointense and hyperintense signal within the lesion were determined from MRI. At 36 minutes after SCI, significant swelling of the spinal cord at the lesion center and extending rostrally and caudally was demonstrated by MRI. Also, at this time point, a hypointense core was identified on T1, PD, and T2 weighted images. Over time this hypointense core reduced in size and in some animals was no longer visible by 8 hours after SCI, although histopathology demonstrated presence of red blood cells. A prominent ring of T2-weighted image hyperintensity, characteristic of edema, surrounded the hypointense core. At the lesion center, this rim of edema occupied the entire unilateral injured cord and in all animals extended to the contralateral side. Administration of HS resulted in increased serum [Na], attenuation of cord swelling, and decreased volume of hypointense core and edema at the last time points. CONCLUSIONS We were able to use MRI to detect rapid and acute changes in the evolution of tissue pathophysiology, and show potentially beneficial effects of hypertonic saline in acute cervical SCI.
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Cohen DM, Patel CB, Ahobila-Vajjula P, Sundberg LM, Chacko T, Liu SJ, Narayana PA. Blood-spinal cord barrier permeability in experimental spinal cord injury: dynamic contrast-enhanced MRI. NMR IN BIOMEDICINE 2009; 22:332-41. [PMID: 19023867 PMCID: PMC2741317 DOI: 10.1002/nbm.1343] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
After a primary traumatic injury, spinal cord tissue undergoes a series of pathobiological changes, including compromised blood-spinal cord barrier (BSCB) integrity. These vascular changes occur over both time and space. In an experimental model of spinal cord injury (SCI), longitudinal dynamic contrast-enhanced MRI (DCE-MRI) studies were performed up to 56 days after SCI to quantify spatial and temporal changes in the BSCB permeability in tissue that did not show any visible enhancement on the post-contrast MRI (non-enhancing tissue). DCE-MRI data were analyzed using a two-compartment pharmacokinetic model. These studies demonstrate gradual restoration of BSCB with post-SCI time. However, on the basis of DCE-MRI, and confirmed by immunohistochemistry, the BSCB remained compromised even at 56 days after SCI. In addition, open-field locomotion was evaluated using the 21-point Basso-Beattie-Bresnahan scale. A significant correlation between decreased BSCB permeability and improved locomotor recovery was observed.
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Sandner B, Pillai DR, Heidemann RM, Schuierer G, Mueller MF, Bogdahn U, Schlachetzki F, Weidner N. In vivo high-resolution imaging of the injured rat spinal cord using a 3.0T clinical MR scanner. J Magn Reson Imaging 2009; 29:725-30. [DOI: 10.1002/jmri.21477] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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Guleria S, Gupta RK, Saksena S, Chandra A, Srivastava RN, Husain M, Rathore R, Narayana PA. Retrograde Wallerian degeneration of cranial corticospinal tracts in cervical spinal cord injury patients using diffusion tensor imaging. J Neurosci Res 2008; 86:2271-80. [PMID: 18335542 DOI: 10.1002/jnr.21664] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Diffusion tensor imaging (DTI) has the potential to reveal disruption of white matter microstructure in chronically injured spinal cords. We quantified fractional anisotropy (FA) and mean diffusivity (MD) to demonstrate retrograde Wallerian degeneration (WD) of cranial corticospinal tract (CST) in cervical spinal cord injury (SCI). Twenty-two patients with complete cervical SCI in the chronic stage were studied with DTI along with 13 healthy controls. Mean FA and MD values were computed for midbrain, pons, medulla, posterior limb of internal capsule, and corona radiata. Significant reduction in the mean FA and increase in MD was observed in the cranial CST in patients with SCI compared with controls, suggesting retrograde WD. Statistically significant inverse FA and MD changes were noted in corona radiata, indicating some restoration of spared white matter tracts. Temporal changes in the DTI metrics suggest progressing degeneration in different regions of CST. These spatiotemporal changes in DTI metrics suggest continued WD in injured fibers along with simultaneous reorganization of spared white matter fibers, which may contribute to changing neurological status in chronic SCI patients.
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Affiliation(s)
- Saurabh Guleria
- Department of Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
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Scholtes F, Phan-Ba R, Theunissen E, Adriaensens P, Brook G, Franzen R, Bouhy D, Gelan J, Martin D, Schoenen J. Rapid, postmortem 9.4 T MRI of spinal cord injury: correlation with histology and survival times. J Neurosci Methods 2008; 174:157-67. [PMID: 18708093 DOI: 10.1016/j.jneumeth.2008.06.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Revised: 06/16/2008] [Accepted: 06/17/2008] [Indexed: 10/21/2022]
Abstract
High field magnetic resonance imaging (MRI) has been increasingly used to assess experimental spinal cord injury (SCI). In the present investigation, after partial spinal cord injury and excision of the whole spine, pathological changes of the spinal cord were studied in spinal cord-spine blocks, from the acute to the chronic state (24 h to 5 months). Using proton density (PD) weighted imaging parameters at a magnetic field strength of 9.4 tesla (T), acquisition times ranging from <1 to 10 h per specimen were used. High in-plane pixel resolution (68 and 38 microm, respectively) was obtained, as well as high signal-to-noise ratio (SNR), which is important for optimal contrast settings. The quality of the resulting MR images was demonstrated by comparison with histology. The cord and the lesion were shown in their anatomical surroundings, detecting cord swelling in the acute phase (24 h to 1 week) and cord atrophy at the chronic stage. Haemorrhage was detected as hypo-intense signal. Oedema, necrosis and scarring were hyper-intense but could not be distinguished. Histology confirmed that the anatomical delimitation of the lesion extent by MRI was precise, both with high and moderate resolution. The present investigation thus demonstrates the precision of spinal cord MRI at different survival delays after compressive partial SCI and establishes efficient imaging parameters for postmortem PD MRI.
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Affiliation(s)
- Felix Scholtes
- Centre for Cellular and Molecular Neurobiology (CNCM), Department of Neuroanatomy, University of Liège, Sart Tilman B36, 4000 Liège, Belgium.
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Ramu J, Herrera J, Grill R, Bockhorst T, Narayana P. Brain fiber tract plasticity in experimental spinal cord injury: diffusion tensor imaging. Exp Neurol 2008; 212:100-7. [PMID: 18482724 PMCID: PMC2453245 DOI: 10.1016/j.expneurol.2008.03.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2008] [Revised: 03/10/2008] [Accepted: 03/12/2008] [Indexed: 11/16/2022]
Abstract
Diffusion tensor imaging (DTI) and immunohistochemistry were performed in spinal cord injured rats to understand the basis for activation of multiple regions in the brain observed in functional magnetic resonance imaging (fMRI) studies. The measured fractional anisotropy (FA), a scalar measure of diffusion anisotropy, along the region encompassing corticospinal tracts (CST) indicates significant differences between control and injured groups in the 3 to 4 mm area posterior to bregma that correspond to internal capsule and cerebral peduncle. Additionally, DTI-based tractography in injured animals showed increased number of fibers that extend towards the cortex terminating in the regions that were activated in fMRI. Both the internal capsule and cerebral peduncle demonstrated an increase in GFAP-immunoreactivity compared to control animals. GAP-43 expression also indicates plasticity in the internal capsule. These studies suggest that the previously observed multiple regions of activation in spinal cord injury are, at least in part, due to the formation of new fibers.
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Affiliation(s)
- Jaivijay Ramu
- Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, Texas 77030
| | - Juan Herrera
- Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, Texas 77030
| | - Raymond Grill
- Department of Neurosurgery, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, Texas 77030
| | - Tobias Bockhorst
- Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, Texas 77030
| | - Ponnada Narayana
- Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, Texas 77030
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Mihai G, Nout YS, Tovar CA, Miller BA, Schmalbrock P, Bresnahan JC, Beattie MS. Longitudinal comparison of two severities of unilateral cervical spinal cord injury using magnetic resonance imaging in rats. J Neurotrauma 2008; 25:1-18. [PMID: 18355154 DOI: 10.1089/neu.2007.0338] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Magnetic resonance imaging (MRI) should be a powerful tool for characterization of spinal cord pathology in animal models. We evaluated the utility of medium-field MRI for the longitudinal assessment of progression of spinal cord injury (SCI) in a rat model. Thirteen adult rats were subjected to a 6.25 or 25 g-cm unilateral cervical SCI, and underwent MRI and behavioral tests during a 3-week study period. MRI was also performed post-mortem. Quantification of cord swelling, hypointense and hyperintense signal, and lesion length were the most valuable parameters to determine and were highly correlated to behavioral and histopathological measures. Immediately after injury, MRI showed loss of gray matter-white matter differentiation, presence of scattered hyperintense signal and local hypointense signal, and cord swelling in both groups. At 7 days after injury, the spinal cord in the 25 g-cm group was significantly larger than that of the 6.25 g-cm group (p = 0.02). Contrast enhancement of the lesion was seen at 24 h in the 6.25 g-cm group, and at 24 h and 7 days in the 25 g-cm group. The volume of hypointense signal, representing hemorrhage, throughout the lesion region was significantly larger in the 25 g-cm compared to the 6.25 g-cm group at both 14 and 21 days after SCI (p, </= 0.04). The appearance of the scattered hyperintense signal, initially representing edema, at later time points changed to a rim of hyperintense signal surrounding the lesion cavity. Significant correlations were found between cord swelling at 7 days after SCI, and lesion length and gray and white matter sparing as determined by histopathology. Other parameters that were highly correlated with histopathology were quantity of hyperintense and hypointense signal, and in vivo lesion length. Hypointense signal and in vivo lesion length were highly correlated to behavior. Significant correlation was also found between parameters determined by MRI: swelling, hypointense signal, hyperintense signal, and lesion length. MRI is a valuable imaging modality to assess the temporal evolution of SCI and to distinguish different severities of cervical SCI in rats. In future, MRI could be applied as a screening tool to either administer goal-directed therapies, or enable even group distribution, prior to therapeutic intervention for example through quantification and matching of swelling and edema.
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Affiliation(s)
- Georgeta Mihai
- Department of Radiology, The Ohio State University, Columbus, Ohio, USA
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Onyszchuk G, He YY, Berman NEJ, Brooks WM. Detrimental effects of aging on outcome from traumatic brain injury: a behavioral, magnetic resonance imaging, and histological study in mice. J Neurotrauma 2008; 25:153-71. [PMID: 18260798 DOI: 10.1089/neu.2007.0430] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Considerable evidence indicates that outcomes from traumatic brain injury (TBI) are worse in the elderly, but there has been little preclinical research to explore potential mechanisms. In this study, we examined the age-related effects on outcome in a mouse model of controlled cortical impact (CCI) injury. We compared the responses of adult (5-6 months old) and aged (21-24 months old) male mice following a moderate lateral CCI injury to the sensorimotor cortex. Sensorimotor function was evaluated with the rotarod, gridwalk and spontaneous forelimb behavioral tests. Acute edema was assessed from hyperintensity on T2-weighted magnetic resonance images. Blood-brain barrier opening was measured using anti-mouse immunoglobulin G (IgG) immunohistochemistry. Neurodegeneration was assessed by amino-cupric silver staining, and lesion cavity volumes were measured from histological images. Indicators of injury were generally worse in the aged than the adult mice. Acute edema, measured at 24 and 48 h post-injury, resolved more slowly in the aged mice (p < 0.01). Rotarod recovery (p < 0.05) and gridwalk deficits (p < 0.01) were significantly worse in aged mice. There was greater (p < 0.01 at 3 days) and more prolonged post-acute opening of the blood-brain barrier in the aged mice. Neurodegeneration was greater in the aged mice (p < 0.01 at 3 days). In contrast, lesion cavity volumes, measured at 3 days post-injury, were not different between injured groups. These results suggest that following moderate controlled cortical impact injury, the aged brain is more vulnerable than the adult brain to neurodegeneration, resulting in greater loss of function. Tissue loss at the impact site does not explain the increased functional deficits seen in the aged animals. Prolonged acute edema, increased opening of the blood-brain barrier and increased neurodegeneration found in the aged animals implicate secondary processes in age-related differences in outcome.
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Affiliation(s)
- Gregory Onyszchuk
- Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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Herrera JJ, Chacko T, Narayana PA. Histological correlation of diffusion tensor imaging metrics in experimental spinal cord injury. J Neurosci Res 2008; 86:443-7. [PMID: 17868152 DOI: 10.1002/jnr.21481] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Diffusion tensor imaging (DTI) has the potential to provide important information about the integrity of white matter tracts in injured spinal cord tissue. It is thought that DTI-based transverse diffusivity (lambda(t)) reflects the state of myelin, whereas longitudinal diffusivity (lambda(l)) reflects axonal integrity. However, this has not been established in spinal cord injury (SCI). Therefore, we performed quantitative histologic analysis on 4- and 8-week post-SCI rodent spinal cords that had received a moderately severe injury at the T7 level and correlated the histology with lambda(t) and lambda(l) measured in vivo. Using antibodies specific to myelin and axonal process (i.e., neurofilament), the percent area of expression was determined in the dorsal, ventral, and lateral white matter from both rostral and caudal regions away from the epicenter of the injury site. The results suggest a positive correlation between lambda(t) and demyelination in many but not all regions. However, these studies failed to establish a correlation between lambda(l) and axonal damage. These results suggest that caution must be exercised in interpreting the DTI metrics in terms of tissue pathology in SCI.
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Affiliation(s)
- Juan J Herrera
- Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, Houston, Texas 77030, USA
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Abstract
Longitudinal magnetic resonance imaging (MRI) was performed in normal and spinal cord (SC)-injured rodents. A fast technique based on polar B-spline snake was developed to extract the SC contour from the MR images in order to estimate the cord atrophy. Based on pooled data from all of the imaging studies, the extracted contours correlated well with manually defined contours. Results from the injured group showed cord atrophy shortly after the contusion injury. The maximum amount of atrophy (9.7% +/- 3.5% decrease in the cross-sectional area (CSA)) occurred mainly at the epicenter around 14 days postinjury. The caudal and rostral segments in the injured group did not exhibit significant atrophy compared to the normal controls. The MRI-based atrophy measurements obtained in injured cords are consistent with previous histological findings.
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Affiliation(s)
- Xiang Deng
- Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, Houston, Texas, USA
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Balla DZ, Faber C. In vivo intermolecular zero-quantum coherence MR spectroscopy in the rat spinal cord at 17.6 T: a feasibility study. ACTA ACUST UNITED AC 2007; 20:183-91. [PMID: 17876622 DOI: 10.1007/s10334-007-0081-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 08/14/2007] [Accepted: 08/17/2007] [Indexed: 12/22/2022]
Abstract
OBJECTIVE The feasibility of in vivo magnetic resonance spectroscopy of the healthy rat spinal cord at 17.6 T using conventional methods and intermolecular zero-quantum coherence (iZQC) spectroscopy is explored and the performance of both approaches is compared. METHODS Localised spectra were acquired at 17.6 T from three healthy Fisher rats and phantoms with injected iron-oxide particles using the PRESS and a modified HOMOGENIZED sequence. RESULTS Well-resolved in vivo spectra showing the four singlet resonances of creatine, choline, and N-acetyl aspartate were obtained with both approaches. iZQC spectra were acquired from larger voxels, but did not provide higher sensitivity or resolution in the healthy spinal cord. In the presence of paramagnetic iron-oxide particles, the quality of in vitro spectra acquired with PRESS declined and was strongly dependent on the quality of the local shim. iZQC spectra were not affected by the presence of iron-oxide particles and provided narrow lines (9 Hz) independent of the shim. CONCLUSION In vivo iZQC spectroscopy of the rat spinal cord is possible. The robustness in presence of local field distortions makes iZQC methods a promising alternative for the investigation of tissue containing labelled cells, implants, or clotted blood. New application of MRS to tissue inaccessible using conventional methods may thus become possible.
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Affiliation(s)
- David Z Balla
- Department of Experimental Physics 5, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
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Ramu J, Bockhorst KH, Grill RJ, Mogatadakala KV, Narayana PA. Cortical reorganization in NT3-treated experimental spinal cord injury: Functional magnetic resonance imaging. Exp Neurol 2007; 204:58-65. [PMID: 17112518 DOI: 10.1016/j.expneurol.2006.09.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 09/27/2006] [Accepted: 09/28/2006] [Indexed: 10/23/2022]
Abstract
Functional magnetic resonance imaging (fMRI) studies were performed for visualizing ongoing brain plasticity in Neurotrophin-3 (NT3)-treated experimental spinal cord injury (SCI). In response to the electrical stimulation of the forepaw, the NT3-treated animals showed extensive activation of brain structures that included contralateral cortex, thalamus, caudate putamen, hippocampus, and periaqueductal gray. Quantitative analysis of the fMRI data indicated significant changes both in the volume and center of activations in NT3-treated animals relative to saline-treated controls. A strong activation in both ipsi- and contralateral periaqueductal gray and thalamus was observed in NT3-treated animals. These studies indicate ongoing brain reorganization in the SCI animals. The fMRI results also suggest that NT3 may influence nociceptive pathways.
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Affiliation(s)
- Jaivijay Ramu
- Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, TX 77030, USA
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Ramu J, Bockhorst KH, Mogatadakala KV, Narayana PA. Functional magnetic resonance imaging in rodents: Methodology and application to spinal cord injury. J Neurosci Res 2007; 84:1235-44. [PMID: 16941500 DOI: 10.1002/jnr.21030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Functional MRI (fMRI) on spinal cord-injured rodents at 4 and 8 weeks post injury (PI) is described. The paradigm for fMRI, based on electrical stimulation of rat paws, was automated using an in-house designed microprocessor-based controller that was interfaced to a stimulator. The MR images were spatially normalized to the Paxinos and Watson atlas using publicly available digital images of the cryosections. In normal uninjured animals, the activation was confined to the contralateral somatosensory cortex. In contrast, in injured animals, extensive activation, which included structures such as ipsilateral cortex, thalamus, hippocampus, and the caudate putamen, was observed at 4 and 8 weeks PI. Quantitative cluster analysis was carried out to calculate the volumes and centers of activation in individual brain structures. Based on this analysis, significant increase in activation between 4 and 8 weeks was observed only in the ipsilateral caudate putamen and thalamus. These studies suggest extensive and ongoing brain reorganization in spinal cord-injured animals.
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Affiliation(s)
- Jaivijay Ramu
- Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, Houston, Texas 77030, USA
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Onyszchuk G, Al-Hafez B, He YY, Bilgen M, Berman NEJ, Brooks WM. A mouse model of sensorimotor controlled cortical impact: characterization using longitudinal magnetic resonance imaging, behavioral assessments and histology. J Neurosci Methods 2006; 160:187-96. [PMID: 17049995 PMCID: PMC1941707 DOI: 10.1016/j.jneumeth.2006.09.007] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Revised: 08/23/2006] [Accepted: 09/01/2006] [Indexed: 10/24/2022]
Abstract
The present study establishes a new mouse model for traumatic brain injury (TBI), using an electromechanically driven linear motor impactor device to deliver a lateral controlled cortical impact (CCI) injury to the sensorimotor cortex. Lesion cavity size was measured, and inter-animal consistency demonstrated, at 14 days post injury. Qualitative information regarding damage progression over time was obtained by scanning with high field magnetic resonance imaging (MRI) at five time points following injury. Functional impairment and recovery were measured with the Rotarod, gridwalk and cylinder tests, and lesion cavity volume was measured post mortem with thionin-stained tissue sections. The study establishes the reliability of a linear-motor based device for producing repeatable damage in a CCI model, demonstrates the power of longitudinal MRI in studying damage evolution, and confirms that a simple battery of functional tests record sensorimotor impairment and recovery.
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Affiliation(s)
- Gregory Onyszchuk
- Hoglund Brain Imaging Center, University of Kansas Medical Center, 3901 Rainbow Boulevard, MS1052, Kansas City, KS 66160, USA
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Li Y, Oskouian RJ, Day YJ, Rieger JM, Liu L, Kern JA, Linden J. Mouse spinal cord compression injury is reduced by either activation of the adenosine A2A receptor on bone marrow-derived cells or deletion of the A2A receptor on non-bone marrow-derived cells. Neuroscience 2006; 141:2029-39. [PMID: 16777350 DOI: 10.1016/j.neuroscience.2006.05.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Revised: 04/21/2006] [Accepted: 05/04/2006] [Indexed: 01/07/2023]
Abstract
Activation of the adenosine A(2A) receptor (A(2A)R) at the time of reperfusion has been shown to reduce ischemia-reperfusion injury in peripheral tissues and spinal cord. In this study we show that treating mice with the A(2A)R agonist, 4-{3-[6-amino-9-(5-cyclopropylcarbamoyl-3,4-dihydroxy-tetrahydro-furan-2-yl)-9H-purin-2-yl]-prop-2-ynyl}-piperidine-1-carboxylic acid methyl ester for four days beginning before or just after the onset of reperfusion after compression-induced spinal cord injury rapidly (within 1 day) and persistently (>42 days) reduces locomotor dysfunction and spinal cord demyelination. Protection is abolished in knockout/wild type bone marrow chimera mice selectively lacking the A(2A)R only on bone marrow-derived cells but retaining receptors on other tissues including blood vessels. Paradoxically, reduced spinal cord injury is also noted in A(2A)R -/- mice, and in wild type/knockout bone marrow chimera mice selectively lacking the A(2A)R on non-bone marrow-derived cells, or in mice treated with the A(2A) antagonist, 4-(2-[7-amino-2-[2-furyl][1,2,4]triazolo[2,3-a][1,3,5]triazin-5-yl-amino]ethyl)phenol. The greatest protection is seen in knockout/wild type bone marrow chimera mice treated with 4-{3-[6-amino-9-(5-cyclopropylcarbamoyl-3,4-dihydroxy-tetrahydro-furan-2-yl)-9H-purin-2-yl]-prop-2-ynyl}-piperidine-1-carboxylic acid methyl ester, i.e. by activating the A(2A)R in mice expressing the receptor only in bone marrow-derived cells. The data suggest that inflammatory bone marrow-derived cells are the primary targets of A(2A) agonist-mediated protection. We conclude that A(2A) agonists or other interventions that inhibit inflammation during and after spinal cord ischemia may be effective in reducing spinal cord injury in patients, but excessive or prolonged stimulation of the A(2A)R may be counterproductive. It may be possible to devise strategies to produce optimal spinal cord protection by exploiting temporal differences in A(2A)R-mediated responses.
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Affiliation(s)
- Y Li
- Department of Medicine, University of Virginia Health System, MR5 Box 801394, Charlottesville, VA 22908, USA
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Deo AA, Grill RJ, Hasan KM, Narayana PA. In vivo serial diffusion tensor imaging of experimental spinal cord injury. J Neurosci Res 2006; 83:801-10. [PMID: 16456864 DOI: 10.1002/jnr.20783] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In vivo longitudinal diffusion tensor imaging (DTI) of rodent spinal cord injury (SCI) was carried out over a period of eight weeks post-injury. A balanced, rotationally invariant, alternating gradient polarity icosahedral diffusion encoding scheme was used for an unbiased estimation of the DTI metrics. The fractional anisotropy (FA), diffusivities along (longitudinal), and perpendicular (transverse) to the fiber tracts, were estimated for the ventral, dorsal, and lateral white matter. In all the three regions, the DTI metrics were observed to be significantly different in injured cords relative to the uninjured controls close to the epicenter of the injury. However, these differences gradually disappeared away from the epicenter. The spatio-temporal changes in the DTI metrics showed a recovery pattern that is region specific. Although the temporal trends in the tissue recovery in rostral and caudal sections seem to be similar, overall the DTI metrics were observed to be closer to the normal tissue values in the caudal relative to the rostral sections (rostral-caudal asymmetry).
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Affiliation(s)
- Aparna A Deo
- Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, Texas 77030, USA
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Ito D, Matsunaga S, Jeffery ND, Sasaki N, Nishimura R, Mochizuki M, Kasahara M, Fujiwara R, Ogawa H. Prognostic value of magnetic resonance imaging in dogs with paraplegia caused by thoracolumbar intervertebral disk extrusion: 77 cases (2000-2003). J Am Vet Med Assoc 2005; 227:1454-60. [PMID: 16279391 DOI: 10.2460/javma.2005.227.1454] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine whether magnetic resonance imaging findings in dogs with paraplegia caused by thoracolumbar intervertebral disk extrusion were predictive of clinical outcome. DESIGN Retrospective case series. ANIMALS 77 dogs. PROCEDURE Medical records and magnetic resonance images were reviewed; clinical outcome was classified as successful (regained ability to walk with no more than mild neurologic deficits) or unsuccessful (severe neurologic deficits persisted). The prognostic value of magnetic resonance imaging was compared with prognostic value of deep pain perception, duration of clinical signs, and rate of onset of clinical signs. RESULT 33 (43%) dogs had areas of hyperintensity of the spinal cord greater than or equal to the length of the L2 vertebral body on T2-weighted magnetic resonance images. All 44 dogs without areas of hyperintensity on T2-weighted images had a successful outcome, but only 18 of the 33 (55%) dogs with an area of hyperintensity did. Only 5 of 16 dogs with an area of hyperintensity that had also lost deep pain perception had a successful outcome. The odds ratio for an unsuccessful outcome for a dog with an area of hyperintensity (29.87) was higher than the odds ratio for a dog that had lost deep pain perception (5.24). Duration and rate of onset of clinical signs were not associated with clinical outcome. CONCLUSIONS AND CLINICAL RELEVANCE Findings suggest that results of magnetic resonance imaging can be used to predict clinical outcome in dogs with paraplegia caused by intervertebral disk extrusion.
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Affiliation(s)
- Daisuke Ito
- Laboratories of Veterinary Emergency Medicine, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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