Cerebral ischemia: Arising due to damage in the vertebral artery-whether the result of injury or an endemic condition- cerebral ischemia is when not enough blood is getting to where it needs to go in the brain.Though cases in which these vessels are damaged due to an accident are relatively rare, the disruption of proper blood flow can certainly impact neurological function. Depending on the injury, blood clotting could arise, or there may be internal bleeding. Trauma: Falls, car accidents, and other issues can lead to injury and blunt trauma to the vertebral arteries and, often, damage to the neck’s vertebrae accompanies the issue.In 47% of cases, these are seen in the cranial area, while in 44% of cases it’s seen in the rear of the artery. Variable orientation of ostium: This refers to differences in the positioning of the openings of the vertebral artery. In most cases, both arteries emerge on the left side, though this can also be seen on the right side or there may be variation in the shape of both sides. Variable origin: An abnormality at the point of the vertebral artery’s origin.Also very rare-it’s only seen in between 0.23% and 1.95% of the population-it’s largely believed to be harmless, though some links have been found with certain kinds of brain aneurysms. Vertebral artery fenestration: This is when the lumen, or inside of the artery, actually splits into two either inside or outside of the cranium.In most cases, though, this condition is asymptomatic. Vertebral artery duplication: As the name implies, this a rare case when the vertebral artery has two sources rather than just one, affecting the course it takes through the neck.

In these cases, the vertebral artery either terminates into the PICA or is absent, which can affect the amount of blood that reaches the brain. Asymmetry: Irregular and insufficient development of arteries, a condition called “vertebral arterial hypoplasia,” can affect this region.V4 (intradural or intracranial): The final section of the vertebral artery ascends behind the hypoglossal nerve, joins up with its counterpart from the other side of the neck, to form the basilar artery at the base of the pons, the part of the brainstem that links the medulla oblongata and thalamus brain regions.This curved shape ensures that the vessel can accommodate head and neck movement. It then twists around to access the dura and arachnoid, the membranes that surround the brain. V3 (atlantic, extradural, or extraspinal): The artery emerges from the C2 vertebrae and sweeps across to pass through the foramen of the top neck vertebrae (C1).V2 (foraminal): The next segment runs through the lower four vertebrae of the neck and is accompanied by nerves, veins (delivering blood back towards the heart), before twisting to form an L-shape to access the second neck vertebrae (C2).V1 (preforaminal): The first, preforaminal segment arises in the subclavian artery of the shoulder and works itself behind the carotid artery (another major source of blood for the brain) to enter the lowest neck vertebrae (C6).

Pica artery anatomy