Wk 1, Case 5 - Review

Patient History
44-year-old male with 3 month history of intermittent pain and redness within the left eye.

Findings
Noncontrast Head CT:

Left-sided proptosis is demonstrated. Asymmetric diffuse thickening of the left-sided extraocular muscles including the superior, lateral, inferior, and medial rectus. There does appear to be a degree of tendinous sparing. The optic nerve is symmetric in size relative to the right. No significant inflammatory stranding within the left orbit. The right orbit is normal.

No evidence of acute infarction. No intracranial hemorrhage. No extra-axial collection. No mass, mass effect, or midline shift. The basal cisterns are patent. Ventricular caliber and configuration is normal.Paranasal sinuses are clear. No mastoid effusion. Bony calvaria and skull base are intact without focal lesion.

CTA Head:

There is asymmetric dilation and early opacification of the left superior ophthalmic vein with enhancement extending to the cavernous sinus such as on series 7 image 129 suspicious for a cavernous carotid fistula. Key images made. There are asymmetric prominent left superficial middle cerebral and middle meningeal veins which are likely outflow drainage. The right supraophthalmic vein is not opacified. There is no CT angiography evidence of a cavernous ICA aneurysm.

The intracranial portions of the internal carotid arteries are patent bilaterally without stenosis. The middle and anterior cerebral arteries are patent bilaterally without a site of stenosis.The left vertebral artery is dominant. Intradural portions of the vertebral arteries are patent bilaterally without stenosis. Vertebral arteries join to form a normal caliber basilar artery. Conventional branching pattern of the basilar artery. Superior cerebellar and posterior cerebral arteries are patent bilaterally without stenosis.No intracranial aneurysm is identified.

Impressions
1. Asymmetric dilation and early opacification of the left superior ophthalmic vein extending to the cavernous sinus suspicious for a cavernous carotid fistula. No CTA evidence of a cavernous carotid aneurysm. Further evaluation with conventional angiography is recommended.

2. Unilateral left proptosis and diffuse enlargement of the extraocular muscles again demonstrated favored to be secondary to suspected cavernous carotid fistula.

3. Patent intracranial circulation with no flow-limiting stenosis. No intracranial aneurysm identified.