Early cerebral venous drainage associated with focal seizures: a correlation of digital subtraction angiography and electroencephalography. Illustrative case

BACKGROUND Early venous drainage is a critical diagnostic feature of arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs). However, other conditions associated with early venous drainage can mimic AVMs and AVFs and mislead the treating physician team. OBSERVATIONS The authors present a unique case of a 56-year-old man with new left hemianopsia. Workup with magnetic resonance imaging and magnetic resonance angiography had revealed cortical enhancement and early venous drainage, possibly caused by an AVF or AVM. Catheter angiography confirmed the presence of early venous drainage of specifically the right occipital lobe. The early venous drainage occurred as the result of local hyperperfusion limited to the right occipital lobe. Subsequent electroencephalography confirmed focal seizure activity in the right occipital lobe. After seizure control with multiple antiepileptic medications, the patient regained his vision. Repeat digital subtraction angiography revealed restoration of normal cerebral blood flow. LESSONS Early venous drainage observed during catheter angiography can be associated with seizure activity. Differentiation from other conditions, such as AVM, AVF, or ischemic stroke, is critical to facilitate prompt and appropriate treatment.