Acquired Chiari malformation Type I associated with a supratentorial arteriovenous malformation

Case report and review of the literature

Restricted access

✓ Chiari malformation Type I (CM-I), a condition defined by caudal descent of the cerebellar tonsils through the foramen magnum, is generally considered a congenital lesion. Several authors, however, have described an acquired form that appears identical to the congenital lesion on neuroimages. The most commonly reported cause of an acquired CM-I is cerebrospinal fluid diversion through a lumboperitoneal shunt. In this paper, the authors report the case of a patient in whom an acquired CM-I developed in association with a supratentorial arteriovenous malformation (AVM) of the brain. Development of the acquired CM was documented on serial magnetic resonance images. Moreover, the CM was seen to originate and worsen in concert with the clinicoradiological progression of the AVM. The underlying mechanism responsible for the acquired CM in this case is thought to be a high-flow venopathy of the transverse and sigmoid sinuses causing occlusion on the right and redirection of venous outflow into posterior fossa veins, with consequent venous congestion and swelling of the posterior fossa structures.

Abbreviations used in this paper: AVM = arteriovenous malformation; CM-I = Chiari malformation Type I; MR = magnetic resonance; SDH = subdural hematoma.

Article Information

Address reprint requests to: H. Hunt Batjer, M.D., Department of Neurological Surgery, The Feinberg School of Medicine, Northwestern University, 676 North St. Clair Street, Suite 2210, Chicago, Illinois 60611. email: hbatjer@nmff.org.

© AANS, except where prohibited by US copyright law.

Headings

Figures

  • View in gallery

    Initial MR images. Axial T2-weighted images of the supratentorial (upper left) and infratentorial (upper right) compartments revealing a large AVM in the right temporal, parietal, and occipital lobes. A sagittal T1-weighted image (lower left) demonstrating normal positioning of the cerebellar tonsils within the posterior fossa. An axial T2-weighted image obtained near the vertex (lower right) revealing a normal flow void in the posterior aspect of the superior sagittal sinus.

  • View in gallery

    Follow-up MR images. Axial T2-weighted images of the supratentorial (upper left) and infratentorial (upper right) compartments revealing an interval increase in number and size of the tortuous AVM vessels. Venous recruitment is evident as well as prolongation of the T2 signal in the adjacent parietooccipital deep white matter. A sagittal T1-weighted image (lower left) revealing 10 mm of cerebellar tonsillar herniation below the foramen magnum. An axial T2-weighted image obtained near the vertex (lower right) demonstrating a poorly delineated flow void in the posterior aspect of the superior sagittal sinus, suggestive of reduced flow and acquired venopathy.

  • View in gallery

    Cerebral angiograms. Anteroposterior (left) and lateral (center) projections after right carotid artery injection revealing the diffuse nature of the AVM with no angiographically identifiable central nidus. A lateral projection after right carotid artery injection (right) demonstrating a pseudophlebitic pattern consistent with intracranial venous hypertension.

  • View in gallery

    Postoperative sagittal T1-weighted MR image demonstrating significant improvement in the tonsillar herniation.

References

  • 1

    Cleland J: Contribution to the study of spina bifida, encephalocele, and anencephalus. J Anat Physiol 17:2572921883

  • 2

    Dagnew Evan Loveren HRTew JM Jr: Acute foramen magnum syndrome caused by an acquired Chiari malformation after lumbar drainage of cerebrospinal fluid: report of three cases. Neurosurgery 51:8238292002

  • 3

    Ellenbogen RGChiari I malformation. Batjer HHLoftus CM: Textbook of Neurological Surgery: Principles and Practices PhiladelphiaLippincott Williams & Wilkins2003. Vol 1:945959

  • 4

    Fung LWGanesan V: Arteriovenous malformations presenting with papilloedema. Dev Med Child Neurol 46:6266272004

  • 5

    Hamilton MGSpetzler RF: The prospective application of a grading system for arteriovenous malformations. Neurosurgery 34:271994

  • 6

    Heros RCKorosue KDiebold PM: Surgical excision of cerebral arteriovenous malformations: late results. Neurosurgery 26:5705781990

  • 7

    Johnston IJacobson EBesser M: The acquired Chiari malformation and syringomyelia following spinal CSF drainage: a study of incidence and management. Acta Neurochir (Wien) 140:4174281998

  • 8

    Lee MRezai ARWisoff JH: Acquired Chiari-I malformation and hydromyelia secondary to a giant craniopharyngioma. Pediatr Neurosurg 22:2512541995

  • 9

    Morioka TShono TNishio SYoshida KHasuo KFukui M: Acquired Chiari I malformation and syringomyelia associated with bilateral chronic subdural hematoma. Case report. J Neurosurg 83:5565581995

  • 10

    Musiek FEBaran JA: Audiological correlates to a rupture of a pontine arteriovenous malformation. J Am Acad Audiol 15:1611712004

  • 11

    Ondra SLTroupp HGeorge EDSchwab K: The natural history of symptomatic arteriovenous malformations of the brain: a 24-year follow-up assessment. J Neurosurg 73:3873911990

  • 12

    Payner TDPrenger EBerger TSCrone KR: Acquired Chiari malformations: incidence, diagnosis, and management. Neurosurgery 34:4294341994

  • 13

    Samson DSBatjer HHPreoperative evaluation of the risk/benefit ratio for arteriovenous malformations of the brain. Wilkins RHRengachary SS: Neurosurgery Update II: Vascular Spinal Pediatric and Functional Neurosurgery New YorkMcGraw-Hill1991. 129133

  • 14

    Sato KJokura HShirane RAkabane TKaribe HYoshimoto T: Trigeminal neuralgia associated with contralateral cerebellar arteriovenous malformation. Case illustration. J Neurosurg 98:13182003

  • 15

    Welch KShillito JStrand RFischer EGWinston KR: Chiari I “malformations”—an acquired disorder?. J Neurosurg 55:6046091981

  • 16

    Williams B: Cerebrospinal fluid pressure-gradients in spina bifida cystica, with special reference to the Arnold-Chiari malformation and aqueductal stenosis. Dev Med Child Neurol Suppl 35:1381501975

  • 17

    Williams B: Chronic herniation of the hindbrain. Ann R Coll Surg Engl 63:9171981

  • 18

    Williams B: Progress in syringomyelia. Neurol Res 8:1301451986

TrendMD

Metrics

Metrics

All Time Past Year Past 30 Days
Abstract Views 167 167 16
Full Text Views 84 84 0
PDF Downloads 73 73 0
EPUB Downloads 0 0 0

PubMed

Google Scholar