Subarachnoid pressure—dependent change in syrinx size in a patient with syringomyelia associated with adhesive arachnoiditis

Case report

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✓ The pathophysiology of syringomyelia is still not well understood. Current prevailing theories involve the assumption that cerebrospinal fluid (CSF) flows into the syrinx from the subarachnoid space through the perivascular space of Virchow—Robin. Reported here is the case of a patient with syringomyelia in which this course is clearly contradicted.

This patient with a holocord syrinx associated with adhesive arachnoiditis was treated 3 years previously with insertion of a subarachnoid—peritoneal shunt and had recently experienced worsening myelopathy. On surgical exploration, the shunt system was functioning normally. The medium-pressure shunt valve was replaced with an adjustable valve with a higher closing pressure setting, thus increasing the CSF pressure in the subarachnoid space. Contrary to prevailing theories, this procedure markedly reduced the size of the syrinx.

This case provides direct evidence that the syrinx size is inversely related to subarachnoid CSF pressure and supports the hypothesis that the pressure gradient across the spinal cord parenchyma is the force that generates syringes in syringomyelia.

Article Information

Address reprint requests to: Han Soo Chang, M.D., Department of Neurological Surgery, Aichi Medical University, Yazako-Karimata, Nagakute-cho, Aichi-gun, Aichi 480-1195, Japan. email: chang@aichi-med-u.ac.jp.

© AANS, except where prohibited by US copyright law.

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Figures

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    Left: Sagittal T2-weighted MR image of the cervical spine obtained before the first surgery. Center: Sagittal T2-weighted MR image of the thoracic spine obtained before the first surgery. Right: A phase-contrast cine-mode MR image of the cervical spine obtained before the first surgery. The white signal indicates downward CSF flow. The arrow shows the point where this downward flow is obstructed at the upper thoracic level.

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    Sagittal T2-weighted MR image of the cervical spine obtained in the patient 2 months after the first surgery.

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    Left: Sagittal T2-weighted MR image of the cervical spine obtained 5 days after foramen magnum decompression. Center: Sagittal T2-weighted MR image obtained 7 months after foramen magnum decompression. Right: Sagittal T2-weighted MR image obtained 2 weeks after replacement of the shunt valve.

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    A: A diagram showing the equilibrium between the pressure gradient across the syrinx wall (white arrowheads) and the wall tension (black arrowheads). B: A diagram showing an attempt to inflate a ball with a one-way valve in a cylinder by increasing the pressure in the cylinder. The parallel lines intersecting the circle represent a channel with a one-way valve. C: A diagram showing an attempt to inflate a ball with a one-way valve in a cylinder by decreasing the pressure in the cylinder. The parallel lines intersecting the circle represent a channel with a one-way valve.

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    Diagram showing our electrical circuit model of the CSF dynamics in the spine. See text for details.

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    Schematic showing the pressure gradient between the inside and outside of the spinal cord: a positive value indicating higher pressure inside is shown. The pressure gradient is shown in the vertical axis, its spatial distribution along the spinal cord in the left to right axis, and its time course after application of a pulsatile wave in the depth axis. Upper Left: Normal setting with almost no pressure gradient developing after application of a sudden pressure increase on the rostral side. Upper Center: The CSF resistance is increased 50-fold between Points 4 and 5. The pressure gradient developed in the segment immediately caudal to the blocked point. Upper Right: After insertion of a resistor simulating the subarachnoid—peritoneal shunt at Point 4. A marked pressure gradient developed in the cervical segment where the shunt was inserted. Lower Left: In addition to the situation depicted in C, the capacitance of the cisterna magna (Ccist in Fig. 5) was increased 10-fold simulating foramen magnum decompression. Lower Right: In addition to the situation in C, the resistance of the inserted shunt was increased 10-fold, simulating the revision of the pressure setting of the shunt valve. The increased pressure gradient seen in C was much decreased.

References

1.

Ball MJDayan AD: Pathogenesis of syringomyelia. Lancet 2:7998011972Ball MJ Dayan AD: Pathogenesis of syringomyelia. Lancet 2:799–801 1972

2.

Beuls EGelan JVandersteen MAdriaensens PVanormelingen LPalmers Y: Microanatomy of the excised human spinal cord and the cervicomedullary junction examined with high-resolution MR imaging at 9.4 Tesla. AJNR 14:6997071993Beuls E Gelan J Vandersteen M Adriaensens P Vanormelingen L Palmers Y: Microanatomy of the excised human spinal cord and the cervicomedullary junction examined with high-resolution MR imaging at 9.4 Tesla. AJNR 14:699–707 1993

3.

Chang HSNakagawa H: Hypothesis on the pathophysiology of syringomyelia based on simulation of cerebrospinal fluid dynamics. J Neurol Neurosurg Psychiatry 74:3443472003Chang HS Nakagawa H: Hypothesis on the pathophysiology of syringomyelia based on simulation of cerebrospinal fluid dynamics. J Neurol Neurosurg Psychiatry 74:344–347 2003

4.

Chang HSNakagawa H: Theoretical analysis of the pathophysiology of syringomyelia associated with adhesive arachnoiditis. J Neurol Neurosurg Psychiatry 75:7547572004Chang HS Nakagawa H: Theoretical analysis of the pathophysiology of syringomyelia associated with adhesive arachnoiditis. J Neurol Neurosurg Psychiatry 75:754–757 2004

5.

Gardner WJ: Hydrodynamic mechanism of syringomyelia: its relationship to myelocele. J Neurol Neurosurg Psychiatry 28:2472591965Gardner WJ: Hydrodynamic mechanism of syringomyelia: its relationship to myelocele. J Neurol Neurosurg Psychiatry 28:247–259 1965

6.

Heiss JDPatronas NDeVroom HLShawker TEnnis RKammerer W: Elucidating the pathophysiology of syringomyelia. J Neurosurg 91:5535621999Heiss JD Patronas N DeVroom HL Shawker T Ennis R Kammerer W: Elucidating the pathophysiology of syringomyelia. J Neurosurg 91:553–562 1999

7.

Hida KIwasaki YKoyanagi ISawamura YAbe H: Surgical indication and results of foramen magnum decompression versus syringosubarachnoid shunting for syringomyelia associated with Chiari I malformation. Neurosurgery 37:6736791995Hida K Iwasaki Y Koyanagi I Sawamura Y Abe H: Surgical indication and results of foramen magnum decompression versus syringosubarachnoid shunting for syringomyelia associated with Chiari I malformation. Neurosurgery 37:673–679 1995

8.

Iskandar BJHedlund GLGrabb PAOakes WJ: The resolution of syringohydromyelia without hindbrain herniation after posterior fossa decompression. J Neurosurg 89:2122161998Iskandar BJ Hedlund GL Grabb PA Oakes WJ: The resolution of syringohydromyelia without hindbrain herniation after posterior fossa decompression. J Neurosurg 89:212–216 1998

9.

Klekamp J: The pathophysiology of syringomyelia—historical overview and current concept. Acta Neurochir 144:6496642002Klekamp J: The pathophysiology of syringomyelia—historical overview and current concept. Acta Neurochir 144:649–664 2002

10.

Klekamp JVölkel KBartels CJSamii M: Disturbances of cerebrospinal fluid flow attributable to arachnoid scarring cause interstitial edema of the cat spinal cord. Neurosurgery 48:1741862001Klekamp J Völkel K Bartels CJ Samii M: Disturbances of cerebrospinal fluid flow attributable to arachnoid scarring cause interstitial edema of the cat spinal cord. Neurosurgery 48:174–186 2001

11.

Milhorat THChou MWTrinidad EMKula RWMandell MWolpert C: Chiari I malformation redefined: clinical and radiographic findings for 364 symptomatic patients. Neurosurgery 44:100510171999Milhorat TH Chou MW Trinidad EM Kula RW Mandell M Wolpert C: Chiari I malformation redefined: clinical and radiographic findings for 364 symptomatic patients. Neurosurgery 44:1005–1017 1999

12.

Milhorat THKotzen RMAnzil AP: Stenosis of central canal of spinal cord in man: incidence and pathological findings in 232 autopsy cases. J Neurosurg 80:7167221994Milhorat TH Kotzen RM Anzil AP: Stenosis of central canal of spinal cord in man: incidence and pathological findings in 232 autopsy cases. J Neurosurg 80:716–722 1994

13.

Milhorat THMiller JIJohnson WDAdler DEHeger IM: Anatomical basis of syringomyelia occurring with hindbrain lesions. Neurosurgery 32:7487541993Milhorat TH Miller JI Johnson WD Adler DE Heger IM: Anatomical basis of syringomyelia occurring with hindbrain lesions. Neurosurgery 32:748–754 1993

14.

Oldfield EHCerebellar tonsils and syringomyelia. J Neurosurg 97:100910102002Oldfield EH Cerebellar tonsils and syringomyelia. J Neurosurg 97:1009–1010 2002

15.

Petit-Lacour MCLasjaunias PIffenecker CBenoudiba FHadj-Rabia MHurth Met al: Visibility of the central canal on MRI. Neuroradiology 42:7567612000Petit-Lacour MC Lasjaunias P Iffenecker C Benoudiba F Hadj-Rabia M Hurth M et al: Visibility of the central canal on MRI. Neuroradiology 42:756–761 2000

16.

Stoodley MA: Pathophysiology of syringomyelia. J Neurosurg 92:106910722000Stoodley MA: Pathophysiology of syringomyelia. J Neurosurg 92:1069–1072 2000

17.

Stoodley MABrown SABrown CJJones NR: Arterial pulsation-dependent perivascular cerebrospinal fluid flow into the central canal in the sheep spinal cord. J Neurosurg 86:6866931997Stoodley MA Brown SA Brown CJ Jones NR: Arterial pulsation-dependent perivascular cerebrospinal fluid flow into the central canal in the sheep spinal cord. J Neurosurg 86:686–693 1997

18.

Stoodley MAGutschmidt BJones NR: Cerebrospinal fluid flow in an animal model of noncommunicating syringomyelia. Neurosurgery 44:106510761999Stoodley MA Gutschmidt B Jones NR: Cerebrospinal fluid flow in an animal model of noncommunicating syringomyelia. Neurosurgery 44:1065–1076 1999

19.

Tubbs RSElton SGrabb PDockery SEBartolucci AAOakes WJ: Analysis of the posterior fossa in children with the Chiari 0 malformation. Neurosurgery 48:105010552001Tubbs RS Elton S Grabb P Dockery SE Bartolucci AA Oakes WJ: Analysis of the posterior fossa in children with the Chiari 0 malformation. Neurosurgery 48:1050–1055 2001

20.

Vassilouthis JPapandreou AAnagnostaras SPappas J: Thecoperitoneal shunt for syringomyelia: report of three cases. Neurosurgery 33:3243281993Vassilouthis J Papandreou A Anagnostaras S Pappas J: Thecoperitoneal shunt for syringomyelia: report of three cases. Neurosurgery 33:324–328 1993

21.

Williams B: Simultaneous cerebral and spinal fluid pressure recordings. 2. Cerebrospinal dissociation with lesions at the foramen magnum. Acta Neurochir 59:1231421981Williams B: Simultaneous cerebral and spinal fluid pressure recordings. 2. Cerebrospinal dissociation with lesions at the foramen magnum. Acta Neurochir 59:123–142 1981

22.

Yamazaki YTachibana SOhta NYada KOhama E: Experimental model of chronic tonsillar herniation associated with early stage syringomyelia. Acta Neuropathol 90:4254311995Yamazaki Y Tachibana S Ohta N Yada K Ohama E: Experimental model of chronic tonsillar herniation associated with early stage syringomyelia. Acta Neuropathol 90:425–431 1995

23.

Yasui KHashizume YYoshida MKameyama TSobue G: Age-related morphologic changes of the central canal of the human spinal cord. Acta Neuropathol 97:2532591999Yasui K Hashizume Y Yoshida M Kameyama T Sobue G: Age-related morphologic changes of the central canal of the human spinal cord. Acta Neuropathol 97:253–259 1999

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