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BMC Veterinary Research Mar 2018Syringomyelia is a pathological condition in which fluid-filled cavities (syringes) form and expand in the spinal cord. Syringomyelia is often linked with obstruction of...
BACKGROUND
Syringomyelia is a pathological condition in which fluid-filled cavities (syringes) form and expand in the spinal cord. Syringomyelia is often linked with obstruction of the craniocervical junction and a Chiari malformation, which is similar in both humans and animals. Some brachycephalic toy breed dogs such as Cavalier King Charles Spaniels (CKCS) are particularly predisposed. The exact mechanism of the formation of syringomyelia is undetermined and consequently with the lack of clinical explanation, engineers and mathematicians have resorted to computer models to identify possible physical mechanisms that can lead to syringes. We developed a computer model of the spinal cavity of a CKCS suffering from a large syrinx. The model was excited at the cranial end to simulate the movement of the cerebrospinal fluid (CSF) and the spinal cord due to the shift of blood volume in the cranium related to the cardiac cycle. To simulate the normal condition, the movement was prescribed to the CSF. To simulate the pathological condition, the movement of CSF was blocked.
RESULTS
For normal conditions the pressure in the SAS was approximately 400 Pa and the same applied to all stress components in the spinal cord. The stress was uniformly distributed along the length of the spinal cord. When the blockage between the cranial and spinal CSF spaces forced the cord to move with the cardiac cycle, shear and axial normal stresses in the cord increased significantly. The sites where the elevated stress was most pronounced coincided with the axial locations where the syringes typically form, but they were at the perimeter rather than in the central portion of the cord. This elevated stress originated from the bending of the cord at the locations where its curvature was high.
CONCLUSIONS
The results suggest that it is possible that repetitive stressing of the spinal cord caused by its exaggerated movement could be a cause for the formation of initial syringes. Further consideration of factors such as cord tethering and the difference in mechanical properties of white and grey matter is needed to fully explore this possibility.
Topics: Animals; Computer Simulation; Dog Diseases; Dogs; Spinal Cord; Syringomyelia
PubMed: 29523203
DOI: 10.1186/s12917-018-1410-7 -
Journal of Veterinary Internal Medicine Nov 2018Cavalier King Charles Spaniels (CKCS) suffer pain associated with Chiari-like malformation and syringomyelia (CMSM). People suffer from a similar condition and describe...
BACKGROUND
Cavalier King Charles Spaniels (CKCS) suffer pain associated with Chiari-like malformation and syringomyelia (CMSM). People suffer from a similar condition and describe numerous sensory abnormalities. Sensory changes have not been quantified in affected CKCS.
OBJECTIVES
To use quantitative sensory testing (QST) to quantify thermal and mechanical thresholds in CKCS and to compare QST in dogs with and without syringomyelia (SM).
ANIMALS
Forty-four CKCS.
METHODS
Prospective study. Dogs underwent neurological examinations and craniocervical magnetic resonance imaging (MRI). Thermal testing was performed over the humerus and thorax (n = 32); mechanical testing was performed on the paw and neck (n = 44). Latencies, thresholds, and response rates were compared with presence and severity of SM on MRI, presence of pain reported by the owner and pain identified on examination.
RESULTS
Thirty dogs had SM, 30 were painful on examination, 29 were owner-reported symptomatic. Thermal and mechanical variables were not significantly different based on presence or severity of SM. Dogs with pain on examination had decreased mechanical thresholds on the paw (0.38 kg, SD = 0.18) and neck (2.05 kg, SD = 0.74) compared to thresholds of dogs without pain on examination on the paw (0.60 kg, SD = 0.30) and neck (2.72 kg, SD = 0.57; P = .021).
CONCLUSIONS AND CLINICAL IMPORTANCE
Mechanical and thermal sensitivity does not appear to be related to the presence of SM, but mechanical sensitivity appears to be related to the presence of pain and clinical signs. Mechanical testing may be useful for assessing sensory abnormalities during clinical trials.
Topics: Animals; Brain; Budd-Chiari Syndrome; Case-Control Studies; Dog Diseases; Dogs; Female; Hypesthesia; Magnetic Resonance Imaging; Male; Neuroimaging; Sensory Thresholds; Syringomyelia
PubMed: 30307645
DOI: 10.1111/jvim.15297 -
Journal of Veterinary Internal Medicine 2006Syringomyelia is a condition that results in fluid-containing cavities within the parenchyma of the spinal cord as a consequence of altered cerebrospinal fluid dynamics.... (Review)
Review
Syringomyelia is a condition that results in fluid-containing cavities within the parenchyma of the spinal cord as a consequence of altered cerebrospinal fluid dynamics. This review discusses the history and the classification of the disorder, the current theories of pathogenesis, and the advanced imaging modalities used in the diagnosis. The intramedullary pulse pressure theory (a new pathophysiologic concept of syringomyelia) also is presented. In addition, the current understanding of the painful nature of this condition is discussed and the current trends in medical and surgical management are reviewed.
Topics: Animals; Arnold-Chiari Malformation; Decision Trees; Dog Diseases; Dogs; Genetic Predisposition to Disease; Magnetic Resonance Imaging; Pedigree; Syringomyelia
PubMed: 16734077
DOI: 10.1892/0891-6640(2006)20[469:sccipd]2.0.co;2 -
Journal of Neurology, Neurosurgery, and... Sep 1994Post-traumatic syringomyelia was previously thought to be an infrequent but serious sequel to spinal cord injury. Clinical and CT studies have shown an incidence of...
Post-traumatic syringomyelia was previously thought to be an infrequent but serious sequel to spinal cord injury. Clinical and CT studies have shown an incidence of between 1% and 5%, but more recently MRI has suggested an incidence of up to 22%. Twenty spinal cords have been examined after death from two days to 43 years after injury. Four had syrinxes, 20% of the series, approaching the incidence found by MRI. The acute and chronic pathological changes after trauma are described. Post-traumatic syringomyelia seems to develop from cores of necrotic tissue (myelomalacic cores) rather than lysis of haematoma. The mechanism of extension of syrinxes remains unexplained.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Female; Humans; Male; Middle Aged; Spinal Cord; Spinal Cord Injuries; Syringomyelia; Time Factors
PubMed: 8089677
DOI: 10.1136/jnnp.57.9.1095 -
BMJ Case Reports Jun 2021The Chiari I malformation (CM-I) is characterised by overcrowding of the posterior fossa and descent of the cerebellar tonsils and is associated with syringomyelia. With... (Review)
Review
The Chiari I malformation (CM-I) is characterised by overcrowding of the posterior fossa and descent of the cerebellar tonsils and is associated with syringomyelia. With the increasing availability of magnetic resonance imaging, CM-I is placing a growing burden on neurosurgical services. However, its natural history remains poorly understood, and the timing and nature of surgical intervention is controversial. We present a case of a significant, symptomatic CM-I with associated syrinx which underwent complete spontaneous resolution over a 4-year period. Spontaneous regression of Chiari malformation and syringomyelia is exceedingly rare; a literature review reveals 15 other cases and only one case which underwent complete resolution. The present case and literature review suggest a more benign natural history of CM-I and support a more conservative approach to its management. Further studies are required to determine whether any factors can predict resolution for certain patient cohorts.
Topics: Arnold-Chiari Malformation; Decompression, Surgical; Humans; Magnetic Resonance Imaging; Syringomyelia; Trachea
PubMed: 34155013
DOI: 10.1136/bcr-2021-241789 -
Cleveland Clinic Journal of Medicine 1992Several theories have been put forth to explain the pathogenesis of syringomyelia, the formation of longitudinal, fluid-filled cavities within the spinal cord. Chief... (Review)
Review
Several theories have been put forth to explain the pathogenesis of syringomyelia, the formation of longitudinal, fluid-filled cavities within the spinal cord. Chief among them is Gardner's hydrodynamic theory, widely accepted for more than two decades. Gardner attributed the genesis of syringomyelia to craniospinal pressure differentials in the setting of fourth ventricular outlet obstruction; these differentials favor cerebrospinal fluid shifts from the fourth ventricle of the brain through the central canal of the spinal cord. Gardner's theory has been questioned, and several alternative theories of syringomyelia have been proposed. Physiological data and new information from magnetic resonance imaging support many of Gardner's concepts; however, a more comprehensive elucidation of the pathophysiologic mechanisms of syringomyelia requires incorporating facets of the other theories. We propose a unified theory of the pathogenesis of syringomyelia based on recent experience with magnetic resonance imaging, and on elements of other current theories.
Topics: Cerebrospinal Fluid Pressure; Humans; Intracranial Pressure; Magnetic Resonance Imaging; Radionuclide Imaging; Syringomyelia
PubMed: 1525970
DOI: 10.3949/ccjm.59.4.373 -
Neurosurgery Feb 2019The origin of syrinx fluid is controversial.
BACKGROUND
The origin of syrinx fluid is controversial.
OBJECTIVE
To elucidate the mechanisms of syringomyelia associated with cerebrospinal fluid pathway obstruction and with intramedullary tumors, contrast transport from the spinal subarachnoid space (SAS) to syrinx was evaluated in syringomyelia patients.
METHODS
We prospectively studied patients with syringomyelia: 22 with Chiari I malformation and 16 with SAS obstruction-related syringomyelia before and 1 wk after surgery, and 9 with tumor-related syringomyelia before surgery only. Computed tomography-myelography quantified dye transport into the syrinx before and 0.5, 2, 4, 6, 8, 10, and 22 h after contrast injection by measuring contrast density in Hounsfield units (HU).
RESULTS
Before surgery, more contrast passed into the syrinx in Chiari I malformation-related syringomyelia and spinal obstruction-related syringomyelia than in tumor-related syringomyelia, as measured by (1) maximum syrinx HU, (2) area under the syrinx concentration-time curve (HU AUC), (3) ratio of syrinx HU to subarachnoid cerebrospinal fluid (CSF; SAS) HU, and (4) AUC syrinx/AUC SAS. More contrast (AUC) accumulated in the syrinx and subarachnoid space before than after surgery.
CONCLUSION
Transparenchymal bulk flow of CSF from the subarachnoid space to syrinx occurs in Chiari I malformation-related syringomyelia and spinal obstruction-related syringomyelia. Before surgery, more subarachnoid contrast entered syringes associated with CSF pathway obstruction than with tumor, consistent with syrinx fluid originating from the subarachnoid space in Chiari I malformation and spinal obstruction-related syringomyelia and not from the subarachnoid space in tumor-related syringomyelia. Decompressive surgery opened subarachnoid CSF pathways and reduced contrast entry into syringes associated with CSF pathway obstruction.
Topics: Adult; Cerebrospinal Fluid; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Subarachnoid Space; Syringomyelia
PubMed: 29618081
DOI: 10.1093/neuros/nyy072 -
Asian Journal of Surgery Apr 2023
Review
Topics: Humans; Syringomyelia; Brain Injuries; Magnetic Resonance Imaging
PubMed: 36435624
DOI: 10.1016/j.asjsur.2022.10.086 -
Acta Neurochirurgica 1995Based on an own material of 19 patients with syringomyelia and on the related literature a survey is given on the diagnosis, differential diagnosis, postoperative... (Review)
Review
Based on an own material of 19 patients with syringomyelia and on the related literature a survey is given on the diagnosis, differential diagnosis, postoperative evaluation and the dynamics of CSF and cyst fluids, using magnetic resonance imaging (MRI). The following conclusions can be drawn: 1. MRI is the preferred method of investigation for diagnosis and differential diagnosis of syringomyelia. 2. Using MRI, it is possible to study fluid flow in the vertebral canal and the movements of the syrinx fluid. The data are as yet limited, but in the future will form an important contribution to our understanding of the pathogenesis of syringomyelia and to the choice of a treatment method. 3. MRI is important for the postoperative follow-up of patients with syringomyelia, including tracking the cyst and detecting complications.
Topics: Arnold-Chiari Malformation; Atrophy; Diagnosis, Differential; Humans; Magnetic Resonance Imaging; Postoperative Complications; Spinal Cord; Syringomyelia
PubMed: 7668137
DOI: 10.1007/BF01428512 -
Acta Neurochirurgica Oct 2020Following spinal cord injury (SCI), the routine use of magnetic resonance imaging (MRI) resulted in an incremental diagnosis of posttraumatic syringomyelia (PTS)....
BACKGROUND
Following spinal cord injury (SCI), the routine use of magnetic resonance imaging (MRI) resulted in an incremental diagnosis of posttraumatic syringomyelia (PTS). However, facing four decades of preferred surgical treatment of PTS, no clear consensus on the recommended treatment exists. We review the literature on PTS regarding therapeutic strategies, outcomes, and complications.
METHODS
We performed a systematic bibliographic search on ("spinal cord injuries" [Mesh] AND "syringomyelia" [Mesh]). English language literature published between 1980 and 2020 was gathered, and case reports and articles examining syrinx due to other causes were excluded. The type of study, interval injury to symptoms, severity and level of injury, therapeutic procedure, duration of follow-up, complications, and outcome were recorded.
RESULTS
Forty-three observational studies including 1803 individuals met the eligibility criteria. The time interval from SCI to the diagnosis of PTS varied between 42 and 264 months. Eighty-nine percent of patients were treated surgically (n = 1605) with a complication rate of 26%. Symptoms improved in 43% of patients postoperatively and in 2% treated conservatively. Stable disease was documented in 50% of patients postoperatively and in 88% treated conservatively. The percentage of deterioration was similar (surgery 16%, 0.8% dead; conservative 10%). Detailed analysis of surgical outcome with regard to symptoms revealed that pain, motor, and sensory function could be improved in 43 to 55% of patients while motor function deteriorated in around 25%. The preferred methods of surgery were arachnoid lysis (48%) and syrinx drainage (31%).
CONCLUSION
Even diagnosing PTS early in its evolution with MRI, to date, no satisfactory standard treatment exists, and the present literature review shows similar outcomes, regardless of the treatment modality. Therefore, PTS remains a neurosurgical challenge. Additional research is required using appropriate study designs for improving treatment options.
Topics: Adult; Decompression, Surgical; Drainage; Female; Humans; Male; Middle Aged; Postoperative Complications; Reoperation; Sensation; Spinal Cord Injuries; Syringomyelia
PubMed: 32820376
DOI: 10.1007/s00701-020-04529-w