Bilateral orbital signs predict cortical venous drainage in cavernous sinus dural AVMs

Background: Most cavernous sinus dural arteriovenous malformations (CSdAVM) have a benign clinical course. Those CSdAVM that drain into cortical veins have an increased risk for neurologic complications. Objective: To find whether a specific clinical sign predicts cortical venous drainage (CVD) in CSdAVM. Methods: The records of 118 patients with CSdAVM were evaluated for the clinical features of the disorder and tested for predictive value of CVD demonstrated angiographically or suggested by MRI using logistic regression and odds ratio (OR) analysis. Results: Clinical signs that predicted the presence of CVD included bilateral orbital signs (p = 0.004, OR = 23.84) and presence of a postauricular bruit (p = 0.035, OR = 23.8). No other clinical sign predicted the presence of CVD, including extraocular muscle dysfunction, abducens or oculomotor dysfunction, increased intraocular pressure, venous stasis retinopathy, choroidal effusion, optic neuropathy, subjective bruit, and objective orbital bruit. Conclusion: Patients who present with or develop bilateral orbital congestion should be recognized as being at increased risk for CVD.