Rotational vertebral artery occlusion syndrome: Misnomers and classification

Rotational vertebral artery occlusion secondary to completely extraosseous vertebral artery

“…In this case, the patient had a hypoplastic left VA along with compression of the right V2 segment, which resulted in reproducible symptoms of VBI on head rotation to the right. Compression of the V2 segment of the VA is most commonly due to cervical osteophytes, 4 but in this case, the narrowing of the right VA was due to extrinsic compression from the thyroid cartilage and possibly the levator scapulae muscle.…”

“…RVAO is a term encompassing all conditions that result in VA stenosis or occlusion with cervical rotation 4 . Bow hunter's syndrome is one of these conditions and is characterized by symptoms of VBI on head rotation secondary to occlusion of the contralateral VA 2 .…”

“…Bow hunter's syndrome is one of these conditions and is characterized by symptoms of VBI on head rotation secondary to occlusion of the contralateral VA 2 . It is more common for occlusion of the VA to occur above the C2 level 4 . VA compression is usually asymptomatic, but if blood flow from the contralateral VA is compromised by hypoplasia, stenosis, or atresia, symptoms of VBI can develop 2 .…”

“…Rotational vertebral artery (VA) occlusion (RVAO) is a possible cause of VBI and is due to compression of the VA on head turning 1 . According to Lee et al, 4 RVAO can be classified into three types: extraosseous segment type (type I), in which the VA is compressed by the thyrocervical trunk and medial border of the scalenus anticus muscle; subaxial spinal type (type II), in which the VA is compressed in an area between the foramen transversarium of C6 and C2; and craniovertebral junction type (type III), in which the VA is compressed in an area between the foramen transversarium of C2 and the foramen magnum. We present a unique case of RVAO in a patient with a completely extraosseous course of the V2 segment of her right dominant VA.…”

Classification of vertebral artery loop formation and association with cervicogenic dizziness

“…Lee et al . classified ‘rotational vertebral artery occlusion syndrome’ into four types according to location and pathology 19 . Kuether et al .…”