Abstract
We report eight cases of vein of Galen aneurysmal malformation (VGAM) assoicated with a “Chiari type I malformation.” In four cases magnetic resonance imaging (MRI) or computed tomography performed in the neonatal period did not demonstrate the posterior fossa anomaly, which appeared on later scans. In the other cases the MRI was performed in infancy and the anomaly was already present. We compared the venous phases of the posterior fossa angiograms and the MRI in these patients. In all eight cases, the angiograms showed a reflux in the cerebellar veins, via the petrous vein, associated with a uni-or bilateral stenosis or thrombosis of the distal posterior dural sinuses. Furthermore, in two cases the posterior fossa returned to normal on MRI following endovascular treatment, while in three cases the herniation of the cerebellar tonsils decreased after the embolization. Tonsillar prolapse becomes irreversible when the venous outlet is incapable of taking the flow even when the VGAM has been treated adequately. In eight additional cases of VGAM for which MRI and angiogram studies were available and in which stenosis or thrombosis of posterior dural sinuses was present without tonsillar prolapse, no reflux into the cerebellar veins was shown. We suggest that the posterior fossa hydrovenous congestion is a result of inadequate venous drainage and that the tonsillar descent is reversible if adequate venous drainage is reconstituted following therapeutic embolization of the fistula. Tonsillar prolapse is not a consequence of mass or raised intraventricular pressure. Our observation suggests that in some other conditions, the “Chiari I malformations” may be secondary to early hydrovenous dysfunction of the posterior fossa.
Similar content being viewed by others
References
Andeweg J (1989) Intracranial venous pressures, hydrocephalus and effects of cerebrospinal fluid shunts. Child's Nerv Syst 5:318–323
Barkovich AJ (1990) Congenital malformations of the brain. In: Barkovich AJ (ed) Pediatric neuroimaging. Raven Press, New York, pp 77–121
Berenstein A, Lasjaunias P (1992) Endovascular treatment of cerebral lesions. (Surgical neuroangiography, vol 4) Springer, Berlin Heidelberg New York, pp 267–317
Lasjaunias P, Terbrugge, K, Lopez Ibor L, Chiu M, Flodmark O, Chuang S, Goasguen J (1987) The role of dural anomalies in vein of Galen aneurysms: report of six cases and review of the literature. AJNR 8:185–192
Lasjaunias P, Berenstein A, Raybaud C (1990) Functional vascular anatomy of brain, spinal cord and spine. (Surgical neuroangiography, vol 3) Springer, Berlin Heidelberg New York, pp 223–296
Lasjaunias P, Garcia-Monaco R, Rodesch G, Terbrugge K (1991) Deep venous drainage in great cerebral vein (vein of Galen) absence and malformations. Neuroradiology 33:234–238
Quisling RG, Mickle PJ (1989) Venous pressure measurements in vein of Galen aneurysms. AJNR 10:411–417
Schwechheimer K (1983) Arteriovenous angioma of the vein of Galen causing cardiac failure in the neonate. Report on clinical and pathological findings in two cases. Neuropediatrics 14:184–187
Stern L, Ramos AD, Wiglesworth FW (1968) Congestive heart failure secondary to cerebral arteriovenous aneurysm in the newborn infant. Am J Dis Child 115:581–587
Zerah M, Garcia-Monaco R, Rodesch G, Terbrugge K, Tardieu M, De Victor D, Lasjaunias P (1992) Hydrodynamics in vein of Galen malformations. Child's Nerv Syst 8:111–117
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Girard, N., Lasjaunias, P. & Taylor, W. Reversible tonsillar prolapse in vein of Galen aneurysmal malformations: report of eight cases and pathophysiological hypothesis. Child's Nerv Syst 10, 141–147 (1994). https://doi.org/10.1007/BF00301078
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00301078