scholarly journals Mechanisms underlying the formation and enlargement of noncommunicating syringomyelia: experimental studies

2000 ◽  
Vol 8 (3) ◽  
pp. 1-7 ◽  
Author(s):  
Marcus A. Stoodley ◽  
Nigel R. Jones ◽  
Liqun Yang ◽  
Christopher J. Brown
Keyword(s):  
Spinal Cord ◽  
Experimental Studies ◽  
Central Canal ◽  
Perivascular Spaces ◽  
Arterial Pulse ◽  
Csf Flow ◽  
Spinal Subarachnoid Space ◽  
Brachiocephalic Trunk ◽  
Rapid Flow ◽  
Arterial Pulsation

The pathogenesis of noncommunicating syringomyelia is unknown, and none of the existing theories adequately explains the production of cysts that occur in association with conditions other than Chiari malformation. The authors' hypothesis is that an arterial pulsation–driven perivascular flow of cerebrospinal fluid (CSF) is responsible for syrinx formation and enlargement. They investigated normal CSF flow patterns in 20 rats and five sheep by using the tracer horseradish peroxidase; the effect of reducing arterial pulse pressure was examined in four sheep by partially ligating the brachiocephalic trunk; CSF flow was examined in 78 rats with the intraparenchymal kaolin model of noncommunicating syringomyelia; and extracanalicular cysts were examined using the excitotoxic model in 38 rats. In the normal animals there was a rapid flow of CSF from the spinal subarachnoid space into the spinal cord perivascular spaces and then into the central canal. This flow ceased when arterial pulsations were diminished. In animals with noncommunicating syringomyelia, there was rapid CSF flow into isolated and enlarged segments of central canal, even when these cysts were causing pressure damage to the surrounding spinal cord. Exitotoxic injury of the spinal cord caused the formation of extracanalicular cysts, and larger cysts were produced when this injury was combined with arachnoiditis, which impaired subarachnoid CSF flow. The results of these experiments support the hypothesis that arterial pulsation–driven perivascular fluid flow is responsible for syrinx formation and enlargement.

Arterial pulsation—dependent perivascular cerebrospinal fluid flow into the central canal in the sheep spinal cord

1997 ◽  
Vol 86 (4) ◽  
pp. 686-693 ◽  
Author(s):  
Marcus A. Stoodley ◽  
Sally A. Brown ◽  
Christopher J. Brown ◽  
Nigel R. Jones
Keyword(s):  
Cerebrospinal Fluid ◽  
Central Canal ◽  
Perivascular Spaces ◽  
Arterial Pulse ◽  
Csf Flow ◽  
Central Gray Matter ◽  
Content Type ◽  
Cerebrospinal Fluid Flow ◽  
Arterial Pulsation ◽  
Central Gray

✓ The impetus for the enlargement of syringes is unknown. The authors hypothesize that there is a flow of cerebrospinal fluid (CSF) from perivascular spaces into the central canal and that the flow is driven by arterial pulsations. Using horse-radish peroxidase as a tracer, the CSF flow was studied in normal sheep, in sheep with damped arterial pulsations, and in sheep with lowered spinal subarachnoid pressure. The CSF flow from perivascular spaces into the central canal was demonstrated in the normal sheep, and two patterns of flow were identified: 1) from perivascular spaces in the central gray matter; and 2) from perivascular spaces in the ventral white commissure. Flow into the central canal was also observed in the sheep with lowered spinal subarachnoid pressure, but not in those with reduced arterial pulse pressure. This study provides evidence that CSF flow from perivascular spaces into the central canal is dependent on arterial pulsations. Arterial pulsation—driven CSF flow may be the impetus for the expansion of syringes.

Evaluation of the central canal of the spinal cord in experimentally induced hydrocephalus

1978 ◽  
Vol 48 (6) ◽  
pp. 970-974 ◽  
Author(s):  
A. Everette James ◽  
William J. Flor ◽  
Gary R. Novak ◽  
Ernst-Peter Strecker ◽  
Barry Burns
Keyword(s):  
Spinal Cord ◽  
Cerebrospinal Fluid ◽  
Experimental Model ◽  
Alternative Pathway ◽  
Central Canal ◽  
Communicating Hydrocephalus ◽  
Csf Flow ◽  
Content Type ◽  
Histological Appearance ◽  
Fine Print

✓ The central canal of the spinal cord has been proposed as a significant compensatory alternative pathway of cerebrospinal fluid (CSF) flow in hydrocephalus. Ten dogs were made hydrocephalic by a relatively atraumatic experimental model that simulates the human circumstance of chronic communicating hydrocephalus. The central canal was studied by histopathology and compared with 10 normal control dogs. In both groups the central canal of the spinal cord was normal in size, configuration, and histological appearance. In this experimental model dilatation of the canal and increased movement of CSF does not appear to be a compensatory alternative pathway.

Ventricular perfusion in cats with kaolin-induced hydrocephalus

1974 ◽  
Vol 41 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Howard M. Eisenberg ◽  
James E. McLennan ◽  
Keasley Welch
Keyword(s):  
Spinal Cord ◽  
Subarachnoid Space ◽  
Central Canal ◽  
Ventricular System ◽  
Ventricular Pressure ◽  
Content Type ◽  
Lateral Ventricles ◽  
Spinal Subarachnoid Space ◽  
Wide Range ◽  
Fine Print

✓ Cats were made hydrocephalic by cisternal instillation of kaolin. Three to 8 weeks later it was found by perfusion between the ventricular system and the spinal subarachnoid space that communication had been reestablished through a demonstrably dilated central canal of the spinal cord. Absorption of fluid from the ventricular system, measured both by ventriculospinal perfusion and, after ligation of the spinal cord, by perfusion between the lateral ventricles, was found to be indistinguishable from zero over a wide range of ventricular pressure.

The Origins of Syringomyelia: Numerical Models of Fluid/Structure Interactions in the Spinal Cord

2005 ◽  
Vol 127 (7) ◽  
pp. 1099-1109 ◽  
Author(s):  
C. D. Bertram ◽  
A. R. Brodbelt ◽  
M. A. Stoodley
Keyword(s):  
Spinal Cord ◽  
Cerebrospinal Fluid ◽  
Wave Propagation ◽  
Numerical Models ◽  
Scar Tissue ◽  
Central Canal ◽  
Radial Wave ◽  
Wave Speeds ◽  
Arterial Pulsation ◽  
Elastic Cord

A two-dimensional axi-symmetric numerical model is constructed of the spinal cord, consisting of elastic cord tissue surrounded by aqueous cerebrospinal fluid, in turn surrounded by elastic dura. The geometric and elastic parameters are simplified but of realistic order, compared with existing measurements. A distal reflecting site models scar tissue formed by earlier trauma to the cord, which is commonly associated with syrinx formation. Transients equivalent to both arterial pulsation and percussive coughing are used to excite wave propagation. Propagation is investigated in this model and one with a central canal down the middle of the cord tissue, and in further idealized versions of it, including a model with no cord, one with a rigid cord, one with a rigid dura, and a double-length untapered variant of the rigid-dura model. Analytical predictions for axial and radial wave-speeds in these different situations are compared with, and used to explain, the numerical outcomes. We find that the anatomic circumstances of the spinal cerebrospinal fluid cavity probably do not allow for significant wave steepening phenomena. The results indicate that wave propagation in the real cord is set by the elastic properties of both the cord tissue and the confining dura mater, fat, and bone. The central canal does not influence the wave propagation significantly.

The influence of the relative timing of arterial and subarachnoid space pulse waves on spinal perivascular cerebrospinal fluid flow as a possible factor in syrinx development

2010 ◽  
Vol 112 (4) ◽  
pp. 808-813 ◽  
Author(s):  
Lynne E. Bilston ◽  
Marcus A. Stoodley ◽  
David F. Fletcher
Keyword(s):  
Spinal Cord ◽  
Fluid Flow ◽  
Subarachnoid Space ◽  
Pulse Wave ◽  
Driving Forces ◽  
Fluid Pressure ◽  
Perivascular Spaces ◽  
Relative Timing ◽  
Csf Flow ◽  
Cerebrospinal Fluid Flow

Object The mechanisms of syringomyelia have long puzzled neurosurgeons and researchers alike due to difficulties in identifying the driving forces behind fluid flow into a syrinx, apparently against a pressure gradient between the spinal cord and the subarachnoid space (SAS). Recently, the synchronization between CSF flow and the cardiac cycle has been postulated to affect fluid flow in the spinal cord. This study aims to determine the effect of changes in the timing of SAS pressure on perivascular flow into the spinal cord. Methods This study uses a computational fluid dynamics model to investigate whether the relative timing of a spinal artery cardiovascular pulse wave and fluid pressure in the spinal SAS can influence CSF flow in the perivascular spaces. Results The results show that the mass flow rate of CSF through a model periarterial space is strongly influenced by the relative timing of the arterial pulse wave and the SAS pressure. Conclusions These findings suggest that factors that might alter the timing of the pulse wave or the fluid flow in the SAS could potentially affect fluid flow into a syrinx.

Pathological basis of spinal cord cavitation in syringomyelia: analysis of 105 autopsy cases

1995 ◽  
Vol 82 (5) ◽  
pp. 802-812 ◽  
Author(s):  
Thomas H. Milhorat ◽  
Anthony L. Capocelli ◽  
Archinto P. Anzil ◽  
Rene M. Kotzen ◽  
Robert H. Milhorat
Keyword(s):  
Spinal Cord ◽  
Subarachnoid Space ◽  
Fourth Ventricle ◽  
Spastic Paraparesis ◽  
Central Canal ◽  
Spinal Cord Tissue ◽  
Content Type ◽  
Age Related ◽  
Spinal Subarachnoid Space ◽  
Fine Print

✓ This report summarizes neuropathological, clinical, and general autopsy findings in 105 individuals with nonneoplastic syringomyelia. On the basis of detailed histological findings, three types of cavities were distinguished: 1) dilations of the central canal that communicated directly with the fourth ventricle (47 cases); 2) noncommunicating (isolated) dilations of the central canal that arose below a syrinx-free segment of spinal cord (23 cases); and 3) extracanalicular syrinxes that originated in the spinal cord parenchyma and did not communicate with the central canal (35 cases). The incidence of communicating syrinxes in this study reflects an autopsy bias of morbid conditions such as severe birth defects. Communicating central canal syrinxes were found in association with hydrocephalus. The cavities were lined wholly or partially by ependyma and their overall length was influenced by age-related stenosis of the central canal. Noncommunicating central canal syrinxes arose at a variable distance below the fourth ventricle and were associated with disorders that presumably affect cerebrospinal fluid dynamics in the spinal subarachnoid space, such as the Chiari I malformation, basilar impression, and arachnoiditis. These cavities were usually defined rostrally and caudally by stenosis of the central canal and were much more likely than communicating syrinxes to dissect paracentrally into the parenchymal tissues. The paracentral dissections of the central canal syrinxes occurred preferentially into the posterolateral quadrant of the spinal cord. Extracanalicular (parenchymal) syrinxes were found typically in the watershed area of the spinal cord and were associated with conditions that injure spinal cord tissue (for example, trauma, infarction, and hemorrhage). A distinguishing feature of this type of cavitation was its frequent association with myelomalacia. Extracanalicular syrinxes and the paracentral dissections of central canal syrinxes were lined by glial or fibroglial tissue, ruptured frequently into the spinal subarachnoid space, and were characterized by the presence of central chromatolysis, neuronophagia, and Wallerian degeneration. Some lesions extended rostrally into the medulla or pons (syringobulbia). Although clinical information was incomplete, simple dilations of the central canal tended to produce nonspecific neurological findings such as spastic paraparesis, whereas deficits associated with extracanalicular syrinxes and the paracentral dissections of central canal syrinxes included segmental signs that were referable to affected nuclei and tracts. It is concluded that syringomyelia has several distinct cavitary patterns with different mechanisms of pathogenesis that probably determine the clinical features of the condition.

scholarly journals The “presyrinx” state: is there a reversible myelopathic condition that may precede syringomyelia?

2000 ◽  
Vol 8 (3) ◽  
pp. 1-13 ◽  
Author(s):  
Nancy J. Fischbein ◽  
William P. Dillon ◽  
Charles Cobbs ◽  
Philip R. Weinstein
Keyword(s):  
Spinal Cord ◽  
Mr Imaging ◽  
Clinical Evidence ◽  
Cervical Spinal Cord ◽  
Central Canal ◽  
Intramedullary Tumor ◽  
Csf Flow ◽  
Before And After ◽  
Late Evolution ◽  
History Of

Object Alteration of cerebrospinal fluid (CSF) flow has been proposed as an important mechanism leading to the development of syringomyelia. We hypothesize that a “presyrinx” condition due to potentially reversible alteration in normal CSF flow exists and that its appearance may be due to variations in the competence of the central canal of the spinal cord. Methods Five patients with clinical evidence of myelopathy, no history of spinal cord trauma, enlargement of the cervical spinal cord with T1 and T2 prolongation but no cavitation, evidence for altered or obstructed CSF flow, and no evidence of intramedullary tumor or a spinal vascular event underwent MR imaging before and after intervention that alleviated obstruction to CSF flow. Results Preoperatively, all patients demonstrated enlarged spinal cords and parenchymal T1 and T2 prolongation without cavitation. Results of magnetic resonance (MR) imaging examinations following intervention in all patients showed resolution of cord enlargement and normalization or improvement of cord signal abnormalities. In one patient with severe arachnoid adhesions who initially improved following decompression, late evolution into syringomyelia occurred in association with continued CSF obstruction. Conclusion Nontraumatic obstruction of the CSF pathways in the spine may result in spinal cord parenchymal T2 prolongation that is reversible following restoration of patency of CSF pathways. We refer to this MR appearance as the “presyrinx” state and stress the importance of timely intervention to limit progression to syringomyelia.

scholarly journals Anthropomorphic Model of Intrathecal Cerebrospinal Fluid Dynamics Within the Spinal Subarachnoid Space: Spinal Cord Nerve Roots Increase Steady-Streaming

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Mohammadreza Khani ◽  
Lucas R. Sass ◽  
Tao Xing ◽  
M. Keith Sharp ◽  
Olivier Balédent ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Spinal Cord ◽  
Cerebrospinal Fluid ◽  
Cfd Model ◽  
Csf Flow ◽  
Nerve Roots ◽  
Csf Dynamics ◽  
Steady Streaming ◽  
Spinal Subarachnoid Space ◽  
The Impact

Cerebrospinal fluid (CSF) dynamics are thought to play a vital role in central nervous system (CNS) physiology. The objective of this study was to investigate the impact of spinal cord (SC) nerve roots (NR) on CSF dynamics. A subject-specific computational fluid dynamics (CFD) model of the complete spinal subarachnoid space (SSS) with and without anatomically realistic NR and nonuniform moving dura wall deformation was constructed. This CFD model allowed detailed investigation of the impact of NR on CSF velocities that is not possible in vivo using magnetic resonance imaging (MRI) or other noninvasive imaging methods. Results showed that NR altered CSF dynamics in terms of velocity field, steady-streaming, and vortical structures. Vortices occurred in the cervical spine around NR during CSF flow reversal. The magnitude of steady-streaming CSF flow increased with NR, in particular within the cervical spine. This increase was located axially upstream and downstream of NR due to the interface of adjacent vortices that formed around NR.

Evidence of CSF Flow in Rostral Direction Through Central Canal of Spinal Cord in Rats

Hydrocephalus ◽  
1991 ◽  
pp. 207-217 ◽  
Author(s):  
Thomas H. Milhorat ◽  
Richard W. Johnson ◽  
Walter D. Johnson
Keyword(s):  
Spinal Cord ◽  
Central Canal ◽  
Csf Flow

The spinal cord central canal in kaolin-induced hydrocephalus

1977 ◽  
Vol 47 (3) ◽  
pp. 397-402 ◽  
Author(s):  
Ansgar Torvik ◽  
V. S. Murthy
Keyword(s):  
Spinal Cord ◽  
Subarachnoid Space ◽  
Fourth Ventricle ◽  
Central Canal ◽  
Content Type ◽  
Spinal Subarachnoid Space ◽  
Individual Variations ◽  
Lower Brain Stem ◽  
Cleft Formation ◽  
Fine Print

✓ In order to study the cause of the great individual variations in kaolin-induced hydrocephalus, the lower brain stem and upper spinal cord were examined histologically in a series of young rabbits that had received injections of kaolin into the cisterna magna. Animals with complete occlusion of the outlets from the fourth ventricle into the subarachnoid space showed only a moderate ventricular dilatation, while cases with marked hydrocephalus also had plugs of kaolin in the caudal part of the fourth ventricle. The intraventricular kaolin was adherent to the roof of the fourth ventricle by strands of connective tissue and it is suggested that the plugs served as valves that initially occluded the opening of the central canal and were then lifted away as the ventricle dilated and the roof moved posteriorly. The animals with marked hydrocephalus also had extensive dilatation of the central canal with cleft formation in the posterior columns. The observations support the concept that in hydrocephalus the central canal may serve as an alternative resorption route for the cerebrospinal fluid through communication with the spinal subarachnoid space.

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