The inner ear depends on a small artery, called the labyrinthine artery, for its blood supply. This artery typically branches off another artery, called the AICA (anterior-inferior cerebellar artery). Both of these arteries are part of a larger network of arteries called the “posterior circulation”, which supplies blood to the brainstem and cerebellum. Similar to other TIAs (transient ischemic attacks) or strokes (damage to brain tissue as a result of impaired blood flow), when blood flow to the vestibular system is interrupted, dizziness ensues. It can also cause other symptoms, including facial weakness, speech and swallowing problems, facial numbness, vision changes, confusion, lethargy, extremity weakness or numbness; all depending on which other parts of the brainstem or cerebellum have interrupted blood supply. Risk factors are similar to other stroke risk factors, including high blood pressure, high cholesterol, obesity, vascular disease/atherosclerosis, heart arrhythmias, and diabetes. Vertebrobasilar insufficiency (VBI) is diagnosed when there is transient and reversible changes in blood supply, and is usually treated with an antiplatelet agent (like aspirin or clopidogrel). Sometimes VBI can be provoked with certain neck positions (like turning the head far to one side). A posterior circulation stroke is a life-threatening medical emergency,
and treatment is usually managed by a stroke neurologist after stabilization in the emergency room.