# December 2020

- Link: https://isnr.in/december-2020/
- Published: 2020-12-31T00:00:00+05:30
- Author: ISNR

December 2020

A 71 year old male presented with 1-year history of ocular symptoms (diplopia, proptosis,
episcleral congestion).

**Case contributed by –**

Department of Imaging Sciences and Intervention Radiology, SCTIMST, Trivandrum (
from ISNR 2020 online quiz)

[⌊Case of the Month December 2020⌉⌊Case of the Month December 2020⌉[

Tangle of vessels in the TOF MRA at the hypoglossal canal. ASL demonstrating arterialized
signal in right cavernous sinus, TOF MRA shows early filling of right cavernous 
sinus, DSA demonstrating feeders, fistula location and venous drainage.

**Final diagnosis – hypoglossal (anterior condylar confluence-acc) dural AV fistula
with retrograde (cavernous sinus) drainage.**

 * Rare posterior fossa dural AV fistula.
 * Fistula is seen between ECA (ascending pharyngeal arteries) and anterior condylar
   vein in the hypoglossal canal
 * It retrogradely drains into cavernous sinus through inferior petrosal sinus and
   manifests like CCF
 * ASL can be useful to identify the fistula by demonstrating arterial signal in
   the veins (cavernous in our case).
 * Treatment: Surgery or embolization.

![Case of the Month December 2020](https://isnr.in/wp-content/uploads/2021/01/image1.
jpg)