Sonographic Clue in Non-traumatic Carotid-cavernous Fistula: Report of a Case and Literature Review.

Background: Failure to recognize a carotid-cavernous fistula (CCF) promptly may lead to worse prognosis due to a setback in providing proper treatment. To promote early diagnosis of non-traumatic CCF, we report a case with classic clinical symptoms and signs that was diagnosed and followed up with carotid Doppler sonography (CDS) and transcranial color-coded duplex (TCD).

Case report: A 45-year-old woman developed an intermittent headache, pulsatile tinnitus, and double vision sequentially within ten days. Progressive left retro-orbital pain, continuous ringing in the left ear, sensory impairment of trigeminal nerve and abducens nerve palsy were also noted on examination. Despite insignificant findings on computed tomography (CT) of the brain, TCD revealed an aberrant flow pattern with high velocity and low resistance at the left carotid siphon. Digital subtraction angiography (DSA) later confirmed a left direct type CCF by illustrating a quick opacification of left cavernous sinus via the internal carotid artery.

Conclusion: In addition to invasive DSA, non-invasive CDS and TCD may serve as useful apparatus during the initial evaluation and subsequent follow-ups. The positive sonographic clues, including abnormal turbulent and hemodynamic parameters, are quite exhibitive in the existence of CCFs.