Reversible tonsillar prolapse and syringomyelia after embolization of a tectal arteriovenous malformation

Abstract

The authors report the case of a 21-year-old woman who presented with headaches, frequent sensations of loss of equilibrium, and intermittent strabismus. A tectal arteriovenous malformation (AVM) was diagnosed based on magnetic resonance (MR) imaging findings. The AVM drained toward the straight sinus and was associated with a tonsillar prolapse (Chiari malformation Type I [CM-I]) and cervical syringomyelia. The tectal AVM was embolized with N-butyl cyanoacrylate, and disconnection of about 80% of the lesion was obtained. All clinical symptoms resolved after embolization, and radiosurgery was proposed to treat the malformation remnant. A control MR image confirmed the regression of the tonsillar prolapse and the disappearance of the syrinx. This report emphasizes that CM-I and syringomyelia may be acquired and related to hydrovenous disorders.

Endoscopic third ventriculostomy in hydrocephalus associated with achondroplasia

“…This is demonstrated in reports of CTH reduced following embolization in patients with arteriovenous malformations involving the vein of Galen. 11,34 Thus, it is likely that elevated dural venous sinus pressures are transmitted "upstream," resulting in increased cerebellar blood volume and "turgor." This in itself may cause fourth ventricle CSF outflow obstruction but may also lead to CTH, which then worsens the degree of CSF obstruction.…”

Symptomatic Syringomyelia Associated With a Dermoid Tumor in the Posterior Fossa -Case Report-

“…This finding may be due to a common mechanism for most cases of syringomyelia associated with Chiari 1 malformation, 15) in which decompression of the foramen magnum without handling of the obex has often proved effective in collapsing the syrinx. 18) Only extirpation of the lesion or careful management of hydrocephalus to reduce intracranial pressure have been reported to resolve cervical syringomyelia caused by supratentorial meningioma, 20) tectal arteriovenous malformation, 17) brainstem glioma, 16) and arachnoid cysts, 14,21,23) whereas the cavity formation and resolution in the present case appeared to be closely associated with the management of Chiari 1 malformation. The syrinx clinically and radiologically disappeared within 12 months of removal of the tumor and posterior fossa decompression, without requiring surgical treatment for the cavitation, as shown in cases associated with other congenital tumors.…”

“…Interestingly, cervical syringomyelia associated with supratentorial meningioma 20) or tectal arteriovenous malformation 17) has also been reported. However, the cervical syrinx is asymptomatic in most cases, because the symptoms of the intracranial lesions predominate, especially if malignant 7,10) or cause increased intracranial pressure through hydrocephalus.…”

Microsurgical Management of Vascular Malformations of the Pineal Region

“…Choque-Velasquez 9 is a consensus that AVMs are acquired lesions caused by endothelial cell disorders, and the postnatal maturation of the intracranial venous system plays an important role in their development. [30][31][32] According to Hernesniemi et al, the prognosis of those lesions is related to the rupture status (worst in ruptured AVMs), the location (worst in deep and infratentorial location), and to the size (worst in AVMs larger than 5 cm in diameter). 6,9,33,34 Anatomic features of pineal region AVMs involve tectal and circumferential feeding arteries arising from the vertebrobasilar system which form a nidus with dilated tectal and superior cerebellar draining veins into the straight sinus.…”