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Bateman GA, Bateman AR. The dilated cortical veins found in multiple sclerosis can explain the reduction in glymphatic flow. Mult Scler Relat Disord 2024; 81:105136. [PMID: 37979409 DOI: 10.1016/j.msard.2023.105136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/11/2023] [Accepted: 11/12/2023] [Indexed: 11/20/2023]
Affiliation(s)
- Grant A Bateman
- Department of Medical Imaging, John Hunter Hospital, Newcastle, NSW, Australia; Faculty of Health, Newcastle University, Callaghan Campus, Newcastle, NSW, Australia.
| | - Alexander R Bateman
- School of Mechanical Engineering, University of New South Wales, Sydney, NSW, Australia
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Bateman GA, Bateman AR. Syringomyelia Is Associated with a Reduction in Spinal Canal Compliance, Venous Outflow Dilatation and Glymphatic Fluid Obstruction. J Clin Med 2023; 12:6646. [PMID: 37892782 PMCID: PMC10607592 DOI: 10.3390/jcm12206646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 10/29/2023] Open
Abstract
The cause of the cystic dilatation of the cord found in syringomyelia has been a source of conjecture for a considerable time. Recent studies have shown that there is a reduction in craniospinal compliance in both childhood hydrocephalus and multiple sclerosis which leads to venous outflow dilatation. Both diseases are associated with glymphatic outflow obstruction. Venous dilatation will narrow the perivenous glymphatic outflow pathway and lead to an increase in glymphatic outflow resistance. Syringomyelia has been shown to be associated with reduced spinal canal compliance. This paper discusses the possibility that venous dilatation and obstructed glymphatic outflow within the cord may be behind the cystic dilatation found within syringomyelia.
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Affiliation(s)
- Grant Alexander Bateman
- Department of Medical Imaging, John Hunter Hospital, Newcastle, NSW 2305, Australia
- Faculty of Health, Callaghan Campus, University of Newcastle, Newcastle, NSW 2308, Australia
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Johnson L, Bartlett-Tomasetig F, Fok S, Whan R, Berliner J, Hemley SJ, Stoodley MA, Bilston LE. A novel method to quantify perivascular space enlargement near the syrinx in a rodent model of post-traumatic syringomyelia. Sci Rep 2023; 13:15043. [PMID: 37700036 PMCID: PMC10497578 DOI: 10.1038/s41598-023-42275-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 09/07/2023] [Indexed: 09/14/2023] Open
Abstract
Posttraumatic syringomyelia (PTS) is an enigmatic condition characterized by the development of fluid-filled cysts (syrinxes) within the spinal cord. Perivascular spaces (PVS) are a critical component of fluid transport within the central nervous system (CNS), with dilated PVSs variably implicated in the pathogenesis of syringomyelia. The extent and spatial distribution of dilated PVSs in syringomyelia, however, remains unclear. This study aims to develop a method to assess PVS dimensions across multiple spinal cord segments in rats with PTS. Syrinxes were induced in two Sprague-Dawley rats at C6/7 with computer-controlled motorized spinal cord impaction; two control rats underwent sham laminectomies. Spinal cord segments were obtained at C4, C6 and C8, cleared via tissue clearing protocols, stained with immunofluorescent antibodies and imaged under confocal microscopy. Qualitative and quantitative analyses of PVS size were performed. Arteriolar PVSs were enlarged in the perisyringeal region of the spinal cord, compared to the control cord. No PVS enlargement was observed above or below the syrinx. These results confirm previous incidental findings of enlarged PVSs in the perisyringeal region, providing new insights into PVS dimensions across multiple spinal segments, and providing a novel method for quantifying spinal cord perivascular space size distributions.
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Affiliation(s)
| | | | - Sandra Fok
- Katharina Gaus Light Microscopy Facility, Mark Wainwright Analytical Centre, UNSW, Sydney, NSW, Australia
| | - Renee Whan
- Katharina Gaus Light Microscopy Facility, Mark Wainwright Analytical Centre, UNSW, Sydney, NSW, Australia
| | - Joel Berliner
- Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Sarah J Hemley
- Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Marcus A Stoodley
- Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Lynne E Bilston
- UNSW Medicine, Sydney, NSW, Australia.
- Neuroscience Research Australia & School of Clinical Medicine, UNSW, Sydney, NSW, Australia.
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Chronic extradural compression of spinal cord leads to syringomyelia in rat model. Fluids Barriers CNS 2020; 17:50. [PMID: 32736591 PMCID: PMC7393857 DOI: 10.1186/s12987-020-00213-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 07/20/2020] [Indexed: 11/23/2022] Open
Abstract
Background Syringomyelia is a common spinal cord lesion. However, whether CSF blockage is linked to the formation and enlargement of syringomyelia is still controversial. The current model of syringomyelia needs modification to more closely mimic the clinical situation. Methods We placed cotton strips under the T13 lamina of 40 8-week-old rats and blocked CSF flow by extradural compression. After 4 and 8 weeks, MRI was performed to evaluate the morphology of syringomyelia and the ratio of spinal cord diameter to syrinx diameter calculated. Locomotor function was evaluated weekly. Spinal cord sections, staining and immunohistochemistry were performed 8 weeks after surgery, the ratio of the central canal to the spinal cord area was calculated, and ependymal cells were counted. In another experiment, we performed decompression surgery for 8 rats with induced syringomyelia at the 8th week after surgery. During the surgery, the cotton strip was completely removed without damaging the dura mater. Then, the rats received MRI imaging during the following weeks and were sacrificed for pathological examination at the end of the experiment. Results Syringomyelia formed in 82.5% (33/40) of rats at the 8-week follow-up. The Basso, Beattie and Bresnahan (BBB) scores of rats in the experimental group decreased from 21.0±0.0 to 18.0 ±3.9 in the first week after operation but returned to normal in later weeks. The BBB score indicated that the locomotor deficit caused by compression is temporary and can spontaneously recover. MRI showed that the syrinx is located in the center of the spinal cord, which is very similar to the most common syringomyelia in humans. The ratio of the central canal to the spinal cord area reached (2.9 ± 2.0) × 10−2, while that of the sham group was (5.4 ± 1.5) × 10−4. The number of ependymal cells lining the central canal was significantly increased (101.9 ± 39.6 vs 54.5 ± 3.4). There was no syrinx or proliferative inflammatory cells in the spinal cord parenchyma. After decompression, the syringomyelia size decreased in 50% (4/8) of the rats and increased in another 50% (4/8). Conclusion Extradural blockade of CSF flow can induce syringomyelia in rats. Temporary locomotor deficit occurred in some rats. This reproducible rat model of syringomyelia, which mimics syringomyelia in humans, can provide a good model for the study of disease mechanisms and therapies.
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Berliner J, Hemley S, Najafi E, Bilston L, Stoodley M, Lam M. Abnormalities in spinal cord ultrastructure in a rat model of post-traumatic syringomyelia. Fluids Barriers CNS 2020; 17:11. [PMID: 32111246 PMCID: PMC7049227 DOI: 10.1186/s12987-020-0171-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 01/18/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Syringomyelia is a serious complication of spinal cord trauma, occurring in approximately 28% of spinal cord injuries. Treatment options are limited and often produce unsatisfactory results. Post-traumatic syringomyelia (PTS) is presumably related to abnormalities of cerebrospinal fluid (CSF) and interstitial fluid hydrodynamics, but the exact mechanisms are unknown. METHODS Transmission electron microscopy (TEM) was used to investigate in detail the interfaces between fluid and tissue in the spinal cords of healthy Sprague-Dawley rats (n = 3) and in a rat model of PTS (n = 3). PTS was induced by computer-controlled impact (75 kDyn) to the spinal cord between C6 and C8, followed by a subarachnoid injection of kaolin to produce focal arachnoiditis. Control animals received a laminectomy only to C6 and C7 vertebrae. Animals were sacrificed 12 weeks post-surgery, and spinal cords were prepared for TEM. Ultra-thin spinal cord sections at the level of the injury were counterstained for structural anatomy. RESULTS Spinal cords from animals with PTS displayed several abnormalities including enlarged perivascular spaces, extracellular edema, cell death and loss of tissue integrity. Additionally, alterations to endothelial tight junctions and an abundance of pinocytotic vesicles, in tissue adjacent to syrinx, suggested perturbations to blood-spinal cord barrier (BSCB) function. CONCLUSIONS These findings support the hypothesis that perivascular spaces are important pathways for CSF flow into and out of the spinal cord, but also suggest that fluid may enter the cord through vesicular transport and an altered BSCB.
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Affiliation(s)
- Joel Berliner
- Faculty of Medicine and Health Sciences, 2 Technology Place, Macquarie University, Sydney, NSW, 2109, Australia.
| | - Sarah Hemley
- Faculty of Medicine and Health Sciences, 2 Technology Place, Macquarie University, Sydney, NSW, 2109, Australia
| | - Elmira Najafi
- Faculty of Medicine and Health Sciences, 2 Technology Place, Macquarie University, Sydney, NSW, 2109, Australia
| | - Lynne Bilston
- Neuroscience Research Australia, Margarete Ainsworth Building, 139 Barker Street, Randwick, NSW, 2031, Australia.,Prince of Wales Clinical School, Faculty of Medicine, University of New South Wales, Randwick, NSW, 2031, Australia
| | - Marcus Stoodley
- Faculty of Medicine and Health Sciences, 2 Technology Place, Macquarie University, Sydney, NSW, 2109, Australia
| | - Magdalena Lam
- Faculty of Medicine and Health Sciences, 2 Technology Place, Macquarie University, Sydney, NSW, 2109, Australia
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Liao S, Ni S, Cao Y, Yin X, Wu T, Lu H, Hu J, Wu H, Lang Y. The 3D characteristics of post-traumatic syringomyelia in a rat model: a propagation-based synchrotron radiation microtomography study. JOURNAL OF SYNCHROTRON RADIATION 2017; 24:1218-1225. [PMID: 29091065 DOI: 10.1107/s1600577517011201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 07/30/2017] [Indexed: 06/07/2023]
Abstract
Many published literature sources have described the histopathological characteristics of post-traumatic syringomyelia (PTS). However, three-dimensional (3D) visualization studies of PTS have been limited due to the lack of reliable 3D imaging techniques. In this study, the imaging efficiency of propagation-based synchrotron radiation microtomography (PB-SRµCT) was determined to detect the 3D morphology of the cavity and surrounding microvasculature network in a rat model of PTS. The rat model of PTS was established using the infinite horizon impactor to produce spinal cord injury (SCI), followed by a subarachnoid injection of kaolin to produce arachnoiditis. PB-SRµCT imaging and histological examination, as well as fluorescence staining, were conducted on the animals at the tenth week after SCI. The 3D morphology of the cystic cavity was vividly visualized using PB-SRµCT imaging. The quantitative parameters analyzed by PB-SRµCT, including the lesion and spared spinal cord tissue area, the minimum and maximum diameters in the cystic cavity, and cavity volume, were largely consistent with the results of the histological assessment. Moreover, the 3D morphology of the cavity and surrounding angioarchitecture could be simultaneously detected on the PB-SRµCT images. This study demonstrated that high-resolution PB-SRµCT could be used for the 3D visualization of trauma-induced spinal cord cavities and provides valuable quantitative data for cavity characterization. PB-SRµCT could be used as a reliable imaging technique and offers a novel platform for tracking cavity formation and morphological changes in an experimental animal model of PTS.
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Affiliation(s)
- Shenghui Liao
- School of Information Science and Engineering, Central South University, Changsha 410008, People's Republic of China
| | - Shuangfei Ni
- Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha 410008, People's Republic of China
| | - Yong Cao
- Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha 410008, People's Republic of China
| | - Xianzhen Yin
- Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, People's Republic of China
| | - Tianding Wu
- Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha 410008, People's Republic of China
| | - Hongbin Lu
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha 410008, People's Republic of China
| | - Jianzhong Hu
- Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha 410008, People's Republic of China
| | - Hao Wu
- Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha 410008, People's Republic of China
| | - Ye Lang
- Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha 410008, People's Republic of China
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Lee JY, Kim SW, Kim SP, Kim H, Cheon JE, Kim SK, Paek SH, Pang D, Wang KC. A rat model of chronic syringomyelia induced by epidural compression of the lumbar spinal cord. J Neurosurg Spine 2017; 27:458-467. [DOI: 10.3171/2016.9.spine16188] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVEThere has been no established animal model of syringomyelia associated with lumbosacral spinal lipoma. The research on the pathophysiology of syringomyelia has been focused on Chiari malformation, trauma, and inflammation. To understand the pathophysiology of syringomyelia associated with occult spinal dysraphism, a novel animal model of syringomyelia induced by chronic mechanical compression of the lumbar spinal cord was created.METHODSThe model was made by epidural injection of highly concentrated paste-like kaolin solution through windows created by partial laminectomy of L-1 and L-5 vertebrae. Behavioral outcome in terms of motor (Basso-Beattie-Bresnahan score) and urinary function was assessed serially for 12 weeks. Magnetic resonance images were obtained in some animals to confirm the formation of a syrinx and to monitor changes in its size. Immunohistochemical studies, including analysis for glial fibrillary acidic protein, NeuN, CC1, ED-1, and caspase-3, were done.RESULTSBy 12 weeks after the epidural compression procedure, syringomyelia formation was confirmed in 85% of the rats (34 of 40) on histology and/or MRI. The syrinx cavities were found rostral to the epidural compression. Motor deficit of varying degrees was seen immediately after the procedure in 28% of the rats (11 of 40). In 13 rats (33%), lower urinary tract dysfunction was seen. Motor deficit improved by 5 weeks after the procedure, whereas urinary dysfunction mostly improved by 2 weeks. Five rats (13%, 5 of 40) died 1 month postoperatively or later, and 3 of the 5 had developed urinary tract infection. At 12 weeks after the operation, IHC showed no inflammatory process, demyelination, or accelerated apoptosis in the spinal cords surrounding the syrinx cavities, similar to sham-operated animals.CONCLUSIONSA novel experimental model for syringomyelia by epidural compression of the lumbar spinal cord has been created. The authors hope that it will serve as an important research tool to elucidate the pathogenesis of this type of syringomyelia, as well as the CSF hydrodynamics of the lumbar spinal cord.
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Affiliation(s)
- Ji Yeoun Lee
- Departments of 1Anatomy and
- 2Neural Development and Anomaly Laboratory, Seoul National University College of Medicine
- 3Division of Pediatric Neurosurgery,
| | - Shin Won Kim
- 2Neural Development and Anomaly Laboratory, Seoul National University College of Medicine
| | - Saet Pyoul Kim
- Departments of 1Anatomy and
- 2Neural Development and Anomaly Laboratory, Seoul National University College of Medicine
| | | | | | - Seung-Ki Kim
- 3Division of Pediatric Neurosurgery,
- 5Department of Neurosurgery, Seoul National University Children's Hospital and Seoul National University College of Medicine, Seoul, Korea
| | - Sun Ha Paek
- 5Department of Neurosurgery, Seoul National University Children's Hospital and Seoul National University College of Medicine, Seoul, Korea
| | - Dachling Pang
- 6Department of Pediatric Neurosurgery, University of California, Davis; and
- 7Regional Center of Pediatric Neurosurgery, Oakland Medical Center, Kaiser Foundation Hospitals of Northern California, Oakland, California
| | - Kyu-Chang Wang
- 2Neural Development and Anomaly Laboratory, Seoul National University College of Medicine
- 3Division of Pediatric Neurosurgery,
- 5Department of Neurosurgery, Seoul National University Children's Hospital and Seoul National University College of Medicine, Seoul, Korea
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Mohrman AE, Farrag M, Huang H, Ossowski S, Haft S, Shriver LP, Leipzig ND. Spinal Cord Transcriptomic and Metabolomic Analysis after Excitotoxic Injection Injury Model of Syringomyelia. J Neurotrauma 2017; 34:720-733. [DOI: 10.1089/neu.2015.4341] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Ashley E. Mohrman
- Department of Chemical and Biomolecular Engineering, University of Akron, Akron, Ohio
| | - Mahmoud Farrag
- Department of Integrated Biosciences Program, University of Akron, Akron, Ohio
| | - He Huang
- Department of Chemistry, University of Akron, Akron, Ohio
| | - Stephan Ossowski
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Stephanie Haft
- Langley Porter Psychiatric Institute, University of California San Francisco, San Francisco, California
| | | | - Nic D. Leipzig
- Department of Chemical and Biomolecular Engineering, University of Akron, Akron, Ohio
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Zuev AA, Lebedev VB, Pedyash NV, Epifanov DS, Levin RS. [Treatment of syringomyelia associated with adhesive arachnoiditis]. ZHURNAL VOPROSY NEIROKHIRURGII IMENI N. N. BURDENKO 2017; 81:39-47. [PMID: 28665387 DOI: 10.17116/neiro201781339-47] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
UNLABELLED The prevalence of syringomyelia (SM) caused by adhesive arachnoiditis (AA) is 2 to 4 cases per 100000 population. Surgical treatment of this pathology usually includes implantation of shunts into the cyst cavity or opening and drainage of the cavity. In this case, SM continues to progress in 72-100% of patients. Unsatisfactory outcomes of this surgical approach necessitate searching for other treatment options. PURPOSE To define the optimal amount of surgery for SM associated with AA and the criteria for assessment of surgery outcomes. MATERIAL AND METHODS The authors treated 47 SM patients in the period from 2010 to 2015. Of these, 34 (72.3%) patients underwent surgery; a total of 40 operations were performed. The patients' age ranged from 18 to 64 years (mean, 43.5 years). Tethering of the spinal cord was eliminated in 25 patients; 9 patients underwent cyst shunting. RESULTS Among operated patients, 5 patients had grade 1 arachnopathy, 13 patients had grade 2 arachnopathy, 12 patients had grade 3 arachnopathy, and 4 patients had grade 4 arachnopathy. The minimal postoperative follow-up period was 11 months. After shunting, the condition improved in 8 of 9 patients; in 7 patients, the condition returned to the baseline level within the first postoperative year; in 6 (66.7%) of these patients, the disease continued to progress. After surgical release of spinal cord tethering, satisfactory long-term results were achieved in 13 (86.6%) patients with grade 1-2 arachnopathy. In 3 (50%) patients with grade 3 arachnopathy, the condition was stabilized. Among patients with grade 4 arachnopathy, progression of the disease was stopped in 1 patient; the condition worsened in 2 (50%) patients. Among all the operated patients, complications developed in 7 patients. There were no lethal outcomes. CONCLUSIONS In grade 1-2 arachnopathy, progression of SM after release of spinal cord tethering occurs only in 13.4% of patients. Therefore, release of spinal cord tethering is recommended for these patients. In grade 3-4 arachnopathy, the rate of relapse after this surgery is more than 80%. Therefore, given the simplicity and a lower risk of complications of cyst shunting, this procedure is advisable for these patients.
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Affiliation(s)
- A A Zuev
- Pirogov National Medical and Surgical Center, Moscow, Russia
| | - V B Lebedev
- Pirogov National Medical and Surgical Center, Moscow, Russia
| | - N V Pedyash
- Pirogov National Medical and Surgical Center, Moscow, Russia
| | - D S Epifanov
- Pirogov National Medical and Surgical Center, Moscow, Russia
| | - R S Levin
- Petrovsky Russian Scientific Center of Surgery, Moscow, Russia
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Pulse wave myelopathy: An update of an hypothesis highlighting the similarities between syringomyelia and normal pressure hydrocephalus. Med Hypotheses 2015; 85:958-61. [PMID: 26362731 DOI: 10.1016/j.mehy.2015.08.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/26/2015] [Indexed: 10/23/2022]
Abstract
Most hypotheses trying to explain the pathophysiology of idiopathic syringomyelia involve mechanisms whereby CSF is pumped against a pressure gradient, from the subarachnoid space into the cord parenchyma. On review, these theories have universally failed to explain the disease process. A few papers have suggested that the syrinx fluid may originate from the cord capillary bed itself. However, in these papers, the fluid is said to accumulate due to impaired fluid drainage out of the cord. Again, there is little evidence to substantiate this. This proffered hypothesis looks at the problem from the perspective that syringomyelia and normal pressure hydrocephalus are almost identical in their manifestations but only differ in their site of effect within the neuraxis. It is suggested that the primary trigger for syringomyelia is a reduction in the compliance of the veins draining the spinal cord. This reduces the efficiency of the pulse wave dampening, occurring within the cord parenchyma, increasing arteriolar and capillary pulse pressure. The increased capillary pulse pressure opens the blood-spinal cord barrier due to a direct effect upon the wall integrity and interstitial fluid accumulates due to an increased secretion rate. An increase in arteriolar pulse pressure increases the kinetic energy within the cord parenchyma and this disrupts the cytoarchitecture allowing the fluid to accumulate into small cystic regions in the cord. With time the cystic regions coalesce to form one large cavity which continues to increase in size due to the ongoing interstitial fluid secretion and the hyperdynamic cord vasculature.
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Shevtsov MA, Senkevich KA, Kim AV, Gerasimova KA, Trofimova TN, Kataeva GV, Medvedev SV, Smirnova OI, Savintseva ZI, Martynova MG, Bystrova OA, Pitkin E, Yukina GY, Khachatryan WA. Changes of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in the model of experimental acute hydrocephalus in rabbits. Acta Neurochir (Wien) 2015; 157:689-98; discussion 698. [PMID: 25591802 DOI: 10.1007/s00701-014-2339-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 12/27/2014] [Indexed: 12/30/2022]
Abstract
BACKGROUND To study the integrity of white matter, we investigated the correlation between the changes in neuroradiological and morphological parameters in an animal model of acute obstructive hydrocephalus. METHODS Hydrocephalus was induced in New Zealand rabbits (n = 10) by stereotactic injection of kaolin into the lateral ventricles. Control animals received saline in place of kaolin (n = 10). The progression of hydrocephalus was assessed using magnetic resonance imaging. Regional fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) were measured in several white matter regions before and after the infusion of kaolin. Morphology of myelinated nerve fibers as well as of the blood-brain barrier were studied with the help of transmission electron microscopy (TEM) and light microscopy. RESULTS Compared with control animals, kaolin injection into the ventricles resulted in a dramatic increase in ventricular volume with compression of basal cisterns, brain shift and periventricular edema (as observed on magnetic resonance imaging [MRI]). The values of ADC in the periventricular and periaqueductal areas significantly increased in the experimental group (P < 0.05). FA decreased by a factor of 2 in the zones of periventricular, periaqueductal white matter and corpus collosum. Histological analysis demonstrated the impairment of the white matter and necrobiotic changes in the cortex. Microsctructural alterations of the myelin fibers were further proved with the help of TEM. Blood-brain barrier ultrastructure assessment showed the loss of its integrity. CONCLUSIONS The study demonstrated the correlation of the neuroradiological parameters with morphological changes. The abnormality of the FA and ADC parameters in the obstructive hydrocephalus represents a significant implication for the diagnostics and management of hydrocephalus in patients.
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Affiliation(s)
- Maxim A Shevtsov
- A.L. Polenov Russian Scientific Research Institute of Neurosurgery, 191014, Mayakovsky str. 12, St. Petersburg, Russia,
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Kobayashi S, Yoshizawa H, Shimada S, Guerrero AR, Miyachi M. Changes of blood flow, oxygen tension, action potential and vascular permeability induced by arterial ischemia or venous congestion on the spinal cord in canine model. J Orthop Res 2013; 31:139-46. [PMID: 22912247 DOI: 10.1002/jor.22197] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 07/06/2012] [Indexed: 02/04/2023]
Abstract
It is generally considered that the genesis of myelopathy associated with the degenerative conditions of the spine may result from both mechanical compression and circulatory disturbance. Many references about spinal cord tissue ischemic damage can be found in the literature, but not detailed studies about spinal cord microvasculature damage related to congestion or blood permeability. This study investigates the effect of ischemia and congestion on the spinal cord using an in vivo model. The aorta was clamped as an ischemia model of the spinal cord and the inferior vena cava was clamped as a congestion model at the 6th costal level for 30 min using forceps transpleurally. Measurements of blood flow, partial oxygen pressure, and conduction velocity in the spinal cord were repeated over a period of 1 h after release of clamping. Finally, we examined the status of blood-spinal cord barrier under fluorescence and transmission electron microscope. Immediately after clamping of the inferior vena cava, the central venous pressure increased by about four times. Blood flow, oxygen tension and action potential were more severely affected by the aorta clamping; but this ischemic model did not show any changes of blood permeability in the spinal cord. The intramedullar edema was more easily produced by venous congestion than by arterial ischemia. In conclusions, venous congestion may be a preceding and essential factor of circulatory disturbance in the compressed spinal cord inducing myelopathy.
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Affiliation(s)
- Shigeru Kobayashi
- Faculty of Medical Sciences, Department of Orthopaedics and Rehabilitation Medicine, The University of Fukui, Shimoaizuki 23, Matsuoka, Fukui 910-1193, Japan.
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