Vertebral artery dominance and hand preference: Is there a correlation?

The two vertebral arteries are usually unequal in size, the left one being generally larger than the right one. It is not clear why this asymmetry exists. One of the hypotheses is that this asymmetry is related to the vascular requirements of the brain. To support this statement, we investigated the correlation between a dominant left vertebral artery and right-handedness and vice versa. No correlation between differences in vertebral artery diameter and hand dominance was found. Hence, the hypothesis that a dominant left vertebral artery is associated with right-handedness and vice versa cannot be confirmed.