PMC9168309_01
Sagittal T2-weighted magnetic resonance images of (a) cervicothoracic and (b) thoracolumbar spines reveal cerebellar tonsillar herniation below the foramen magnum and holocord syringomyelia. (c) Coronal view of three-dimensional magnetic resonance myelography of the whole spine clearly demonstrates the septations in the syrinx. At the lower spinal cord, syringomyelia (arrowheads) affected predominantly on the right side.
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At the lower spinal cord, syringomyelia affected predominantly on the right side [Figure 1].
(a) Sagittal T2-weighted magnetic resonance image and (b) coronal view of three-dimensional magnetic resonance myelography of the thoracolumbar spine demonstrate the progression of syringomyelia at the lower spinal cord and edema in the conus medullaris.
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Follow-up full spinal MRI showed the progression of syringomyelia at the lower spinal cord and edema in the conus medullaris [Figure 2].
(a-e) Sequential axial, (f) coronal T2-weighted, (g and h) sagittal T1-weighted magnetic resonance images, and (i) contrast-enhanced magnetic resonance angiography reveal a large brain arteriovenous malformation involving the right parietal and occipital lobes with markedly dilated cortical draining veins (arrows) and diffuse engorgement of dural venous sinuses (asterisks), including the posterior two-third portion of the superior sagittal sinus, bilateral transverse sinuses, torcula, and straight sinus. There is a large venous varix (black arrows) in the anterior portion of the nidus, probably protruded into the posterior horn of the right lateral ventricle. In addition, dilated posterior fossa veins (arrowheads) are noted.
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No hydrocephalus was seen [Figure 3].
(a) Anteroposterior (AP) and (b) lateral views of the right internal carotid artery (ICA), (c) AP view of the left ICA, (d) lateral view of the right external carotid artery, (e) AP view of the left external carotid artery, and (f) lateral view of the left vertebral artery injections show a large right parieto-occipital arteriovenous malformation (AVM) supplied by enlarged cortical branches of the right middle cerebral artery, and posterior cerebral artery with multiple dural supply. Dural supply to the AVM includes the meningohypophyseal and inferolateral branches of the right cavernous ICA, bilateral middle meningeal arteries, and right occipital artery. In addition, there is indirect supply through leptomeningeal anastomosis from the cortical branches of the right anterior cerebral artery. The AVM drains toward the superior sagittal sinus through enlarged cortical veins. A large venous varix (arrowhead) is noted.
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AVM drained predominantly toward the SSS through enlarged parietal and occipital cortical veins [Figure 4]. Another venous drainage drained into the right transverse sinus through the dilated occipital basal veins.
Anteroposterior view of the left vertebral artery injection illustrates retrograde venous reflux into bilateral enlarged basal veins of Rosenthal (arrowheads) and dilated vein running along left-sided brainstem (arrows) corresponding with dilated posterior fossa veins on magnetic resonance images.
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In addition, venous draining of the inferior compartment of the AVM drained into the straight sinus and the vein of Galen with retrograde venous reflux into bilateral enlarged basal veins of Rosenthal and dilated vein running along left-sided brainstem corresponding with dilated posterior fossa veins on MRI [Figure 5].
(a-d) Anteroposterior views of different injections from the branches of the right middle cerebral artery through the microcatheters reveals the fistulous sites of arteriovenous malformation with markedly dilated cortical draining veins. A large venous varix (arrowhead) is noted. (e and f) During embolization with N-butyl cyanoacrylate. (g) Anteroposterior and (h) lateral views of unsubtracted image demonstrate the glue cast.
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Superselective catheterization of the middle cerebral branches demonstrated the fistulous type of AVM [Figure 6].
(a and b) Axial, (c) coronal, and (d) sagittal views of cranial computed tomography scan reveal intraventricular hemorrhage (arrowheads) in the right lateral and fourth ventricles with ventricular enlargement.
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Cranial computed tomography (CT) scan showed intraventricular hemorrhage in the right lateral and fourth ventricles with ventricular enlargement [Figure 7].
(a) Anteroposterior view of the right posterior cerebral artery, lateral view of (c) the right occipital artery, and (e) the right middle meningeal artery injections the fistulous sites of arteriovenous malformation with markedly dilated cortical draining veins. (b, d, and f) During glue injections with good penetration into the proximal draining veins. (g and h) During Onyx injections through the contralateral middle meningeal branch in anteroposterior view.
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During a period of 2 years, the patient underwent several staged embolization with NBCA and onyx through the branches of the right posterior cerebral artery, bilateral middle meningeal arteries, and right occipital artery [Figure 8].
Cerebral angiography obtained before radiosurgery. (a) Anteroposterior (AP), (b) lateral views of the right internal carotid artery (ICA), (c) AP view of lateral view of the left ICA, (d) lateral view of the right external carotid artery, (e) AP view of the left ECA, and (f) lateral view of the left vertebral artery injections demonstrate significant reduction in size and flow of the brain arteriovenous malformation.
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Final cerebral angiography after embolization demonstrated a significant reduction in size and flow of the brain AVM [Figure 9].
Cranial computed tomography scan obtained following several staged embolization shows no ventricular enlargement and metal artifact from embolic material.
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Follow-up cranial CT scan showed no hydrocephalus [Figure 10].
Sagittal T2-weighted magnetic resonance images of (a) cervicothoracic and (b) thoracolumbar spines reveal significant resolution of the syrinx cavity as compared to the previous images.
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A control whole-spine MRI revealed significant reduction in syrinx size [Figure 11].