A De Novo Sphenoparietal Dural Arteriovenous Fistula: Unveiling the Deceitful Culprit

Introduction: Intracranial dural arteriovenous fistulas (DAVFs) are an uncommon pathology, and a sphenoparietal drainage pattern is certainly rare. We present a case of a de novo sphenoparietal DAVF in a prepubescent patient previously treated for a cerebellar arteriovenous malformation (AVM) 10 years before. Case Description: A 10-year-old boy presented with worsening headaches for the past few weeks, swelling of the right side of face and eye, and chemosis and proptosis of the right eye. Of note, the patient had been treated successfully for a cerebellar AVM at 6 weeks of age with advanced imaging follow-up until 4 years previously demonstrating resolution of AVM and no other abnormalities whatsoever. Suspecting a carotid cavernous fistula, we performed angiography, which revealed a sphenoparietal DAVF with feeders from both the external and internal carotid artery. Despite sudden onset of symptoms and recent previously negative imaging, bony erosion was noted on computed tomography of the head and orbits. Successful treatment was achieved via transvenous embolization. Conclusions: This case highlights the different array of presentations that sphenoparietal fistulas may display. Even though most DAVFs are acquired, secondary lesions and spontaneous malformations must be considered in a differential diagnosis.