case_images: PMC11799692_01
case_images: Axial computed tomography (CT) scans of the brain: (a and b) non-contrast images and (c-e) contrast-enhanced images reveal a large enhancing varix adjacent to the occipital sinus, along with bilateral dilated cerebellar veins. Encephalomalacic changes are observed in the left frontal lobe. (f) Axial bone-window CT scan shows evidence of a previous left frontoparietal craniotomy. Arrowheads in (d and e) indicate the enhancing varix, and arrows in (d and e) indicate the enhancing occipital sinus.
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case_images: F1
case_images: Initially evaluated at a local hospital, a computed tomography (CT) scan of his brain revealed abnormal vascular structures in the posterior fossa [Figure 1], prompting referral to our institute for further assessment and management.
case_images: Magnetic resonance imaging of the brain obtained 2 weeks after symptom onset. (a) Axial T1-weighted, (b) axial fluid-attenuated inversion recovery, (c) axial T1-weighted with contrast, (d) sagittal T1-weighted with contrast, and (e) coronal T2* weighted gradient echo images reveal a large venous pouch with heterogeneous signal intensity in the anteroinferior aspect, likely indicating a partially thrombosed aneurysm. This large aneurysm is situated anterior to the occipital sinus. Bilateral dilated cerebellar veins are also observed. The asterisk (*) in T2-weighted gradient echo (GRE) imaging is used to denote the sequence type, a convention to describe the imaging technique.
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case_images: F2
case_images: These findings were consistent with a DAVF of the OS with malignant cortical venous reflux [Figures 2 and 3].
case_images: Sagittal maximum intensity projection image from contrast-enhanced magnetic resonance angiography demonstrates multiple dilated and tortuous vessels around the midline occipital bone, along with a large venous varix.
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case_images: F3
case_images: These findings were consistent with a DAVF of the OS with malignant cortical venous reflux [Figures 2 and 3].
case_images: Cerebral angiography demonstrating multiple arterial injections to reveal the dural arteriovenous fistula at the occipital sinus. (a) Anteroposterior (AP) and (b) lateral views of the right vertebral artery (VA) injection, (c) AP and (d) lateral views of the left VA injection, (e) AP and (f) lateral views of the right occipital artery (OA) injection, (g) AP and (h) lateral views of the left OA injection, (i) AP and (j) lateral views of the right external carotid artery (ECA) injection, and lateral view of the left (k) ECA and (l) internal carotid artery injection reveal a dural arteriovenous fistula at the occipital sinus. Numerous branches, including bilateral occipital arteries, middle meningeal arteries, a dural branch of posterior inferior cerebellar arteries, and the left meningohypophyseal trunk, feed this fistula. Arrowheads in (d and f) indicate the occipital sinus.
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case_images: F4
case_images: The caudal portion of the OS was occluded [Figures 4 and 5].
case_images: (a and b) Sagittal maximum intensity projection-reformatted images of angiographic computed tomography of the left vertebral artery (VA), (c) coronal, and (d) sagittal views of 3D reconstruction images fused from the right and left VAs clearly demonstrate the occipital sinus dural arteriovenous fistula draining into a large venous varix, cerebellar veins, and the anterior spinal vein. Asterisks in (a, b, and d) indicate the occipital sinus, and arrowheads in (b) indicate the anterior spinal vein.
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case_images: F5
case_images: The caudal portion of the OS was occluded [Figures 4 and 5].
case_images: (a and b) Fibered coil placement within the large venous pouch under road mapping guidance. (c) Coil deployment in the occipital sinus. (d) The lateral view of an unsubtracted image shows dense coiling within the venous pouch and occipital sinus.
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case_images: F6
case_images: Consequently, transvenous embolization (TVE) was performed through the right transverse sinus using fibered coils, achieving nearly complete obliteration of the fistula [Figure 6].
case_images: Cerebral angiography obtained 3 years after embolization. Anteroposterior (AP) views of the (a) right and (b) left vertebral artery (VA), (c) lateral view of the left VA, AP view of the (d) right occipital artery and (e) external carotid artery (ECA), (f) lateral view of the right ECA, (g) AP view of the left ECA, and lateral view of the left (h) ECA and (i) internal carotid artery injections confirm complete obliteration of the fistula.
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case_images: F7
case_images: Follow-up imaging, including MRI, MRA, and cerebral angiography, confirmed complete obliteration of the OS DAVF with no signs of recurrence [Figure 7].
case_images: PMC11799692_02
case_images: Sagittal T2-weighted image of the cervical spine shows an abnormal hyperintense T2 signal, indicative of venous congestion extending from the medulla to the C6 level.
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case_images: F8
case_images: A cervical spine MRI conducted at the local hospital raised suspicion of a spinal cord tumor, resulting in a referral to our institute [Figure 8].
case_images: (a) Coronal and (b) axial non-contrast computed tomography (CT) scans of the brain show encephalomalacic changes in the bilateral anterior and inferior frontal lobes. (c and d) Axial bone-window CT scans demonstrate a linear fracture (arrowheads) at the left occipital calvarium involving the left condylar canal.
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case_images: F9
case_images: On admission, a CT scan of the brain revealed an old cerebral contusion in the bilateral anterior and inferior frontal lobes, as well as a linear fracture in the left posterior fossa [Figure 9].
case_images: (a and b) Coronal and (c) sagittal maximum intensity projection images from contrast-enhanced magnetic resonance angiography demonstrate a dural arteriovenous fistula of the occipital sinus with downward drainage into dilated spinal veins. The arrow in (c) indicates the fistulous point, and arrowheads in (a) and (b) indicate the anterior spinal vein.
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case_images: F10
case_images: MRA identified a DAVF of the OS, with drainage into both the anterior and posterior spinal veins, causing venous congestion of the cervical cord [Figure 10].
case_images: (a-d) Anteroposterior and (e-h) lateral views of the left vertebral artery injection from arterial to late venous phases reveal an occipital sinus dural arteriovenous fistula fed by the meningeal branch of the left posterior inferior cerebellar artery, with drainage into the anterior and posterior spinal veins. Arrows in (e and f) indicate the fistulous point.
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case_images: F11
case_images: The cranial portion of the OS was occluded [Figures 11 and 12].
case_images: Oblique views of (a) the left vertebral artery injection and (b) a 3D-reconstruction image clearly demonstrate the occipital sinus dural arteriovenous fistula (arrowhead) fed by the meningeal branch of the left posterior inferior cerebellar artery. (c) Sagittal maximum intensity projection-reformatted image of angiographic computed tomography of the left vertebral artery clearly illustrates the occipital sinus, along with the anterior and posterior spinal veins. (d) The top view of a 3D reconstruction image, including body structures, also shows the fistula at the occipital sinus.
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case_images: F12
case_images: The cranial portion of the OS was occluded [Figures 11 and 12].
case_images: Cerebral angiography obtained 2 weeks post-surgery. (a) Anteroposterior and (b) lateral views of the left vertebral artery confirm complete obliteration of the fistula.
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case_images: F13
case_images: Post-procedural angiography confirmed complete obliteration of the OS DAVF, and a follow-up MRI demonstrated a reduction in cervical cord congestion [Figures 13 and 14].
case_images: Magnetic resonance imaging obtained 2 months post-surgery. Sagittal images show (a) T2-weighted, (b) T1-weighted, and (c) contrast-enhanced T1-weighted sequences, revealing a significant reduction in cervical venous congestion, with residual patchy enhancement extending from C2 to C5. (d) Contrast-enhanced magnetic resonance angiography of the brain and cervical spine confirms the absence of fistula recurrence.
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case_images: F14
case_images: Post-procedural angiography confirmed complete obliteration of the OS DAVF, and a follow-up MRI demonstrated a reduction in cervical cord congestion [Figures 13 and 14].