Scalp vein sign caused by intracranial dural arteriovenous fistula.

A 68-year-old man presented with a headache that had started 1 month earlier. The scalp vein dilatation was observed at presentation. The findings of computed tomography and magnetic resonance imaging raised suspicion of a dural arteriovenous fistula, leading to the definitive diagnosis by digital subtraction angiography. Scalp vein signs can be a useful clue to suspect intracranial abnormalities, including dural arteriovenous fistula.