Hypothesis on the pathophysiology of syringomyelia based on simulation of cerebrospinal fluid dynamics

Objectives: Despite many hypotheses, the pathophysiology of syringomyelia is still not well understood. In this report, the authors propose a hypothesis based on analysis of cerebrospinal fluid dynamics in the spine. Methods: An electric circuit model of the CSF dynamics of the spine was constructed based on a technique of computational fluid mechanics. With this model, the authors calculated how a pulsatile CSF wave coming from the cranial side is propagated along the spinal cord. Results: Reducing the temporary fluid storage capacity of the cisterna magna dramatically increased the pressure wave propagated along the central canal. The peak of this pressure wave resided in the mid-portion of the spinal cord. Conclusions: The following hypotheses are proposed. The cisterna magna functions as a shock absorber against the pulsatile CSF waves coming from the cranial side. The loss of shock absorbing capacity of the cisterna magna and subsequent increase of central canal wall pressure leads to syrinx formation in patients with Chiari I malformation.

[1]  G. Sobue,et al.  Age-related morphologic changes of the central canal of the human spinal cord , 1999, Acta Neuropathologica.

[2]  P. Lasjaunias,et al.  Visibility of the central canal on MRI , 2000, Neuroradiology.

[3]  P. Kramer.  The pathogenesis of syringomyelia. , 1962, The Journal of the Indiana State Medical Association.

[4]  Gardner Wj,et al.  HYDRODYNAMIC MECHANISM OF SYRINGOMYELIA: ITS RELATIONSHIP TO MYELOCELE. , 1965 .

[5]  L. Vanormelingen,et al.  Microanatomy of the excised human spinal cord and the cervicomedullary junction examined with high-resolution MR imaging at 9.4 Tesla. , 1993, AJNR. American journal of neuroradiology.

[6]  Surgical treatment of syringomyelia based on magnetic resonance imaging criteria. , 1992 .

[7]  M. Stoodley,et al.  Cerebrospinal fluid flow in an animal model of noncommunicating syringomyelia. , 1999, Neurosurgery.

[8]  W. Gardner,et al.  Hydrodynamic mechanism of syringomyelia: its relationship to myelocele , 1965, Journal of neurology, neurosurgery, and psychiatry.

[9]  W. Gardner,et al.  The cause of syringomyelia and its surgical treatment. , 1958, Cleveland Clinic quarterly.

[10]  T. Shawker,et al.  Elucidating the pathophysiology of syringomyelia. , 1999, Journal of neurosurgery.

[11]  S. Glasser.  On arterial physiology, pathophysiology of vascular compliance, and cardiovascular disease. , 2000, Heart disease.

[12]  Christopher J. Brown,et al.  Arterial pulsation-dependent perivascular cerebrospinal fluid flow into the central canal in the sheep spinal cord. , 1997, Journal of neurosurgery.

[13]  H. Abe,et al.  Surgical indication and results of foramen magnum decompression versus syringosubarachnoid shunting for syringomyelia associated with Chiari I malformation. , 1995, Neurosurgery.

[14]  T. Milhorat,et al.  Pathological basis of spinal cord cavitation in syringomyelia: analysis of 105 autopsy cases. , 1995, Journal of neurosurgery.

[15]  B. Iskandar,et al.  The resolution of syringohydromyelia without hindbrain herniation after posterior fossa decompression. , 2000, Journal of neurosurgery.

[16]  B. Williams.  Surgical treatment for syringomyelia. , 1987, Nursing Times.

[17]  T. Milhorat,et al.  Stenosis of central canal of spinal cord in man: incidence and pathological findings in 232 autopsy cases. , 1994, Journal of neurosurgery.

[18]  H. Nakagawa,et al.  Physical Analysis of CSF Dynamics in the Spine , 2001 .

[19]  T. Isu,et al.  Foramen magnum decompression with removal of the outer layer of the dura as treatment for syringomyelia occurring with Chiari I malformation. , 1993, Neurosurgery.

[20]  M C Speer,et al.  Chiari I malformation redefined: clinical and radiographic findings for 364 symptomatic patients. , 1999, Neurosurgery.

[21]  W. J. Oakes,et al.  Analysis of the Posterior Fossa in Children with the Chiari 0 Malformation , 2001, Neurosurgery.