Vascular abnormalities of the dura mater, irrigated by carotid branches or vertebral arteries before penetrating the dura mater. The occipital artery is one of the main “feeders”.
Generally adjacent to venous sinuses, mainly the transverse sinus.
Not of genetic origin, but acquired: collateral revascularisation after thrombosis of venous sinus.
Clinical signs when symptomatic: pulsatile tinnitus, headache, papilloedema, reduced vision.
Treatment: embolisation (onyx, bioglu) and/or surgery.