[A case of dural arteriovenous fistula requiring differentiation from herpes simplex encephalitis]

A 65-year-old man was admitted to our hospital following a sudden loss of consciousness and seizures. He presented with fever, and a head MRI revealed lesions in the left medial and lateral temporal lobes, as well as the thalamus. Initially, he was treated for suspected limbic encephalitis, including herpes simplex encephalitis (HSE). While his seizures resolved, aphasia persisted. Subsequent tests ruled out infections or autoimmune encephalitis, and a repeat MRI showed dilation of the left Labbe's vein. Further vascular examination, including MRA, 4D-CTA, and digital subtraction angiography (DSA), confirmed the presence of a dural arteriovenous fistula (dAVF), which drained from the left occipital artery and middle meningeal artery via the left Labbe's vein into the superior sagittal sinus. The patient underwent transarterial embolization for treatment. This case highlights the need to consider a dAVF in the differential diagnosis when a patient presents with seizures, fever, and temporal lobe lesions.